# Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit



## Hanatsu

External link: APL1

*Want to start off this review by saying that this is without doubt one of the better products I've come across for a long time. Many thanks to "Raimonds" here on the forum, the designer of this product - who introduced and let me demo this product.*

APL1, basically an advanced equalizer which utilizes FIR (Finite Impulse Response). It can form any curve you desire with very few restrictions, in addition to that it also corrects phase deviations in all minimum phase regions.

Instead of reciting the entire spec I'll just copy/paste it from the official website.



> _APL1 – Unbeatable Quality in Pocket Size
> 
> APL1 is a FIR based 2 channel equalizer with 4096 coefficient FIR filters per channel allowing curve resolution of up to 6Hz. It is capable of creating any arbitary Amplitude Frequency Respone (AFR), Phase Frequency Response (PFR) or Delay Frequency Response (DFR) suitable for very detailed and accurate corrections and equalization in critical applications such as studio monitors, headphones and car audio systems.
> 
> USB connection allows the upload of correction filter files to APL1 unit even in the middle of a live performance without any disturbdances in sound. The unit can optionally have a 16 preset memory accessible trough an external, freely placeable rotary switch, excellent for car audio installations.
> APL1 is available in three different configurations:
> 
> *1. RCA model for car usage – 4 RCA connectors for analog in/out, 2 – for SPDIF digital coaxial in/out, 2 TOSLINK digital in/out
> *
> 2. XLR model – 4 XLR connectors for analog in/out, 2 RCA– for SPDIF digital coaxial in/out, 2 TOSLINK digital in/out
> 
> 3. XLR model with optional AES/EBU digital in/out - 4 XLR connectors for analog in/out, 2 RCA– for SPDIF digital coaxial in/out, 2 TOSLINK digital in/out; 2 XLR for AES/EBU digital in/out
> 
> Specifications:
> 
> *Number of processing channels: 2
> *Resolution: 48kHz/24bits
> *Frequency resolution of correction curve: 6 Hz, 4096 coefficients at 24 kHz bandwidth
> 
> *Inputs: 2 analog balanced, digital - SPDIF coaxial and TOSLINK optical, AES/EBU on order
> 
> *Outputs - 2 analog (XLR balanced), digital - SPDIF coaxial and TOSLINK optical, AES/EBU on order
> 
> *Input/output analog signal max levels: +10dBu (can be changed on order)
> *Analog input/output connection types: RCA or XLR
> *Analog input impedance: 10 kOhm
> *Analog output impedance: 150 Ohm
> *Common mode signal rejection (CMSR) of analog input – 90 dB
> *Dynamic range (analog input/output):104 dBA.
> *THD (analog input/output): 0,07%
> *Signal delay: 1.6 ms (analog input/output), 2.4 ms (digital input/output)
> *Control and upload interface: USB
> *Interface computer system: Microsoft Windows
> *Power: 6.5 to 16 V DC, 3.5 W.
> *Dimensions 15х20х5.3 cm._


Let's begin with some pictures:

Good packaging...















Let's take a look inside:

















A little summary of the pictures. The components are high-grade as far as I can tell, ICs from Burr-Brown and ST. The circuit board is sturdy and it looks overall well engineered. I really like the USB connector, lots better than those small mini/micro USB connectors. Connections are gold-plated and feels sturdy, you don't break the board when you pull of those tight RCAs. Removable power connector for quick install/removal.

*The impressive part is yet to come though!*

Here's the software...



Does it look complicated or perhaps different? Let's "dumb it down" a bit.



*A few notes here:*

*1. APL measures and applies a curve which YOU CHOOSE.

2. Any curve can be modified or created saved as a simple text file. APL will interpolate adjacent frequencies.

3. APL uses multiple measurement points to find out the true sound power response (direct sound + reflections) of the listening space. This is feature different from using pink noise and an RTA.*

You can choose the "window" of the impulse response which basically determines the low-end accuracy. For car-audio use, Raimonds recommended 200ms length. You only need to choose the appropriate file and leave it at that. Nothing complicated.



Here's some "real life" use. Those who have read all my measurement guides and various threads involving DSPs should be used to my frequent use of graphs to display objective data.. Sooo - here's a few for you 

Initial setup - Simple 2-way passive + sub - No EQ (Crossovers at 100Hz 24dB/oct acoustic both ways). The null at 70Hz is a modal cancellation. Left/Right power response shown.



Previous setup - Basic EQ and a few shelf filters applied using a MiniDSP. Left/Right power response shown.



Some additional fixes after measurements with APL...



The APL software then calculates based on the correction and target response to give you this, (left channel shown / "semi-flat" setting):



Before I get into the subjective part. Let's continue with some additional software presentation:



This is a neat little "extra" program that calculates filters, target responses, EQ, corrections etc. It outputs your curve to a text file that APL software can read and apply in different ways. Of course you can make one for each channel. 

*Gain 20dB +/-
*Q from 0.1 to 100
*Center freq from 5-48000Hz.
*Low/High shelf filters.
*Low/high pass filters.

Pretty neat. There's a large room for customization here.


*Here's the actual software to hardware interface:*



You can store 16 presets in the unit and it only takes a second to shift between different settings. You just choose the *.fir file generated by the APL software and import it into this interface and you're done. Enjoy 

As I always do I like to confirm results or at least compare. Before using APL I used RoomEQ to a large extent (it still very useful, don't get me wrong). Again, even if you're not that accustomed to measuring you probably know of some of the procedure involving it, you basically measure around your head and average it together. APL is using a different method. With APL you measure the entire listening space, not just around your head. As a result the "ordinary" method using RoomEQ (or some other measurement program) differs from APL's result. When I first noticed this, I was skeptical because I always found my method quite accurate and correlated well with what I heard...

The thing I first noticed was that APL's version of flat didn't at all sound "flat", as in "RTA-flat". This made me curious to see how APL derived and displayed the curve. Below are results from RoomEQ using spatial average measurement method (headspace), using RTA and Noise with infinite averaging method.







Well, this is interesting indeed. "APL Flat" isn't actually "RTA-Pink Noise flat". If you were to use white noise as excitation signal, the results are fairly consistent with "flat". Using pink noise, it does create a downwards tilted curve explaining how the difference between "flat" and "flat". Another interesting thing is that the right side (passenger side) is lower in amplitude than the left side. This is consistent with the listening experiments I did when I derived my "house curve/target response" in RoomEQ. 

And... thirdly, look how good the curves sum. A testament that APL indeed performs proper phase correction between left and right.

_*What does this mean? It means that APL does indeed derives data and compensating correctly and it correlates exactly with what we hear.*_

*Conclusion & Subjective analysis*

*This is a very powerful unit, very different from the EQ available in the DSPs available for car use. Different in a good way, it can do things any "normal" DSP can't and it's easy and straightforward to use.

*T/A and L/R EQ issues are gone with this unit. The acoustic center is perfect, even a simple 2-way passive system like mine sounded like a competition grade car. Depth is improved subjectively. Everything sounds clearer, more transparent and so easy to listen at. No annoying frequencies that stand out, even crappy recordings that normally is un-listenable suddenly becomes tolerable. The center focus is insane, the up-front bass is improved by an enormous amount (in this car). With a crossover point at 100Hz/24dB both ways, the sub was impossible to localize with any material _(any amount of processing won't fix resonances in the car or non-linear distortion so take that into account)_ . The image stayed up-front and kept staying there. 

(_I am aware that the result varies, if you already got an audiophile grade competition car the improvement is less than with a "normal" install but in my opinion it's still worth every penny. It's that good.)_

*My noise-free preamp is still broken so I couldn't run I/O tests but I'll tell you, it's transparent as far I can hear. No noise whatsoever, I even maxed volume with a 0 bit track but nothing. Couldn't hear any coloration with the unit in "raw-passthrough". 

*This unit does NOT replace an ordinary DSP, in fact you need an ordinary DSP as well. You place the APL1 unit before the DSP - 2RCA's in - 2 out. Not more complicated that that. If you don't own a DSP and is interested in this product, I recommend using it together with a MiniDSP (among the cheapest and best on the market). 

*Support and feedback is great! The value in this is enormous with these types of products.

*Overall a 10/10 score from me. Will use it in my main competition build...*

Link to Raimonds profile; Car Audio | DiyMobileAudio.com | Car Stereo Forum - View Profile: Raimonds


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds has developed another software called TDA as well.

APL :: TDA

Not tried it yet though... will soon


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## teldzc1

Excellent in depth review. This product looks pretty amazing. Would be great if it had built in xover and TA as well. Just to clarify, you need to by the other software as well as the actual APL1 unit to actually tune right?


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## Beckerson1

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Keeping an eye on this as you said. Powerful tool

In the right hands this can take a system that much further


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## Hanatsu

teldzc1 said:


> Excellent in depth review. This product looks pretty amazing. Would be great if it had built in xover and TA as well. Just to clarify, you need to by the other software as well as the actual APL1 unit to actually tune right?


Well, the software that does the actual measuring can be used without the hardware unit. There's a VST-plugin for use with foobar2000 (for example) that carPC guys can use. You could of course use the software+VST in any home audio application if you use a mediacenter/computer as source.

With the amount of money people spend on audio equipment that makes little or no difference I find this APL-system quite cheap for the improvement given. Tried it both with my home audio system as well as my cheap computer speakers and it does improve both staging and tonality. It makes cheap stuff sound much better than you thought was possible. Not trying to act salesman here but I think the money spent on highend source units/DACs/amps could instead be spent on proper processing, especially if we're talking car audio. 

Sent from my Samsung Galaxy S5 using Tapatalk


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## Hanatsu

teldzc1 said:


> Excellent in depth review. This product looks pretty amazing. Would be great if it had built in xover and TA as well. Just to clarify, you need to by the other software as well as the actual APL1 unit to actually tune right?


Then it would have to be multichannel as well. This could be a future project for Raimonds though. Implementing APL correction in an ordinary DSP with 2in10out channels. Now that would be a unique DSP 

Sent from my Samsung Galaxy S5 using Tapatalk


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Your positive review and the other thread have me impressed with how powerful of a tool this is. I only wonder how it would fit into my system. I currently have all my processing in the head unit, and wonder how this unit handles sound post processing......With flat eq on input of course. A multichannel unit would probably be necessary, as I'm sure 4 two channel pieces would be cost prohibitive. Even then, can these units work together in multiples........maybe an 8 channel is down the road......


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Agree with Hanatsu - it is hard not to be a good "seller" promoting this amazing device. I do remember some comments to my posts about one year ago, when I tried to describe my first reaction on this unit. I can not say anything but positive about this unit (APL1).
It was my best investment during my almost 25 years in caraudio ...
By the way APLAUDIO has different models, for example with balanced inputs (XLR) or even a modification for 6 channels called APL3 - very practical when you are building multimedia in a car (supports easily 5.1).










Regarding time alignment - you can use a demo version of TDA software (free). My sub is in trunk. Even it is in a close box - delay is about 25 ms.
In order to adjust front compared to sub in a time domain I have used the third program, which was not mentioned by Hanatsu yet: Coneq C1. Even the max delay value is only 5 ms, it is possible to "delay" it several times using FIR-file. After 4 sessions I was already about the goal. The newest version of TDA (version 9) can also generate a text file comprising of three columns: frequency, delay and power responce. Non-linear distortions versus frequencies can be seen on a graf as well as delay graf in 2D, 3D, impulse responce, etc. 

Another practical feature is that you can asign one path for all these programs and use it for quick corrections. Listen - correct - apply (send to unit) - listen again, etc.


APL1 can be also used for analysis of the components in every setup. Just was wondering how SUB gain works on my HU (Alpine CDA-137BTi) - as an example. It is a powefull and at the same time easy to use device for research/investigation purposes.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Do not forget that EMMA refferies gave two 1 places to the setup with APL products in 2014 (Zalzburg, Eurofinals), and awarded the car provided with APL1 unit with the title - the best sounded car in 2013. No more words needed.


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## ansuser

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So, what we see here is a low power DSP with limited number of taps and some sophisticated measurement technique (pls. correct me if I wrong)

*Hanatsu*, can you please clarify some points:
1. Do I need to measure power response in full sphere around the headrest or, for example, in some plane with center at the headrest? Will changing measurement points field alter my results?

2. Windowed measurements in the car are almost useless, and with 200 ms window I don't really see how it can be different from simple pink noise "moving mic" technique 

3. What about FR in the listening point using good old REW with single point or averaged? Is it comparable to what you were able to achieve before?

4. FIR filters are great for managing phase. Can you control phase with this device? Are implemented filters minimum phase or linear phase? Square wave response plots would be great to see.

5. Open source FIR filter-generation tools are well developed and tested. What exactly separates APL from them (except hardware, obviously)?


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



ansuser said:


> So, what we see here is a low power DSP with limited number of taps and some sophisticated measurement technique (pls. correct me if I wrong)
> 
> *Hanatsu*, can you please clarify some points:
> 1. Do I need to measure power response in full sphere around the headrest or, for example, in some plane with center at the headrest? Will changing measurement points field alter my results?
> 
> 2. Windowed measurements in the car are almost useless, and with 200 ms window I don't really see how it can be different from simple pink noise "moving mic" technique
> 
> 3. What about FR in the listening point using good old REW with single point or averaged? Is it comparable to what you were able to achieve before?
> 
> 4. FIR filters are great for managing phase. Can you control phase with this device? Are implemented filters minimum phase or linear phase? Square wave response plots would be great to see.
> 
> 5. Open source FIR filter-generation tools are well developed and tested. What exactly separates APL from them (except hardware, obviously)?


4096 FIR-taps is quite adequate imo. Most car audio DSPs doesn't use FIR based processing at all. Those which use FIR, doesn't really have an accurate method of obtaining a correct power response. Alpine H800 is probably what comes closest but the how the Imprint calculation algorithm performs is questionable. 

1. You measure the entire listening space, from the left side window to the right window, from dash height to the roof, all the way from the dash to the seated position. So 'everywhere' in the listening space where the main reflections occur. 

2. 200ms is required to get enough resolution in low frequencies, you can choose a much smaller window if you like. I'm fully aware of the limitations and usability of gated measurements in a car. As I'm not the designer of the unit or software I can't give you a well educated answer, I can only observe and review the outcome.

3. I posted graphs from RoomEQ measured using pink noise/RTA, using a "traditional" measuring method in my first post. I can't EQ the response to equal that of the APL. I could get it close but it did not sound or stage the same. I believe it has to do with the summed response. Even if the L/R response is close to that APL outputs the summed response look very different with peaks and dips all over the place. APL does delay/phase corrections as well.

4. Believe it performs minimum phase correction. It definitely "clears up" the the time domain. While I'm not sure, I believe it performs time alignment corrections at the same time as amplitude correction. I leave Raimonds to answer that properly though.

5. I've tried multiple FIR based DSP/computer software able to generate FIR filters. I've messed around with the openDRC miniDSPs with rePhase and a few other programs. They have not impressed me even after extensive experimentation. Perhaps I should not blame the software, it does what it's supposed to do, it's the way you obtain the data. APL uses multiple point sweeps which derives data from an IR. A noise generator coupled with an RTA won't be able to display any data about phase/time domain, which APL does and corrects for. What APL does better, much better than other software I've tried is the way it measures, averages and derives the data from measurements. Again, I don't know the specifics how it works, I can only tell you that it does. It's much more user friendly than most other solutions with similar properties.


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



ansuser said:


> Will changing measurement points field alter my results?


Forgot to answer that. I did the same type of measurements with noise and ordinary sine sweeps at multiple points with REW. I did not get the same results as APL or close to them after averaging. As far as I can tell, APL performs some kind of "weighed averaging". Beyond 200 points, my results were fairly consistent every time.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Of course there is some know-how behind this unit and its soft. What differs this device from other product - is attempt to describe some theoretical background for this method. Some usefull information is present on the vendor's site, which to my mind can give answers to all these questions raised by ansuser. Another difference is that correction method is protected by a number of patents (in USA, Canada and other countries). I do not remember other DSP's with such protection. According to the manufacturer, the idea was awarded by "Pro Sound News Europe" as the best innovation in the field in 2005 and got the AES prize in 2007. Since 2011 that method has been adapted to caraudio application and finally got "best sound" prize at EMMA Eurofinals in 2013. So this small unit can do its job, I think (Has bought APL1 unit in 2012).

I can just confirm - it is minimum phase, and do not forget - 4096 filters in the range 20-20000 Hz compared to other DSP on the marked, which have typically about 31 filters to control the frequency response. This means resolution of about 6 Hz per filter. 

Besides automatical correction of phase during caclulations, it has possibility to delay separate channels manually - this feature can be applied several times for fine tuning in the phase domain. Using TDA soft you will get exact delay values in msec for left and right channels (both in 2d, 3d-graphical presentations and output txt-file).

Appart from autotuning (for example Imprint for PXA100), correction method applied for APL1 unit is unlimited for further adjustments, which could be made by C1 parametric EQ and implemented in no time - new FIR-file will be sent immediately to the unit and you will be able to hear results just after that.

Making averaging in listening position (or even testing only one point near the driver's headrest) will represent only small part of the information obtained by covering the whole space during the acoustic power measurements. Such measurements are well known in industry for testing noise level of pumps, motors, compressors, ets. You will need to know emitted power from them, that is why measurements should cover the whole surface around the noise source. Something similar is here with APL correction method.

Regarding pink noise tests vers. sinus sweep signal, tha later is better protected from backgroung noise and intermodulations dew to the fact that full dynamic range can be used for a single requency, and not simultaniously for the whole range of pink noise. 

I personally tried to tune my system with different DSP's (max - 31 bands) and was not satisfied with the results. What APL1 did in my car - simply amazing. It made rather cheap setup playing rich sound with a deep sceene and tons of microdetails in music records. I'm able to listen more instruments than before. This actually changed little my music preferences, moving to big bands with more complicated sounds, as masking is much less now.

It is my (user's) impression of APL1 unit, For technical specs pls contact the vendor or visit his site: Acoustic Power Lab :: Home

What about pricing - to my mind is little bit more expensive (hardware+software) compared to the majority of DSP's on the market. But you get what you pay. I never regreat any cent spent on this device, more over - it saved a lot of my lifetime (no need of nightmare tuning...).
In simpler words - champion sound to every car can be obtained at let say moderate price. 

Sure, it is excellent device for professional installers, as they need to by only one copy of soft (+licence). For end users -400 USD just for APL1 - seems to be acceptable, am I right?

Missing details: Android and iOS app for control of this unit, blutooth port. But this is nothing with sound quality to do.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Forgot to tell - by increase of gating during the measurements, one should achieve less accuracy for higher frequences. That is why I decided to use only 100ms as my sub (closebox) had delay less than 50ms compared to front speakers. In the case of vented port or even more complicated enclosures (4thband, etc) - using of 200ms gating can be more preferable, but this can be validated by several attempts and comparing the results.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Practical experience with APL:
One more thing that is rather important - how stable is this device in a real life. Let summarize a little. I had it about two years. Outside air temperature range was appr. -12 degrees Selcium (min) during the winter period and about +32 in summer time (max). Cabin temperature was not measured. No garage.The unit was placed in the trunk just behind the rear passenger seat - with natural ventilation (no fans). Would like to report - no issues at all. 

The same is with the software. It took some time to install all the components, including TDA (for time delay measurements), but since then - no problem. As it was recommended by the manufacturer, I have installed soft on the safe USB flash memory card and now can use every PC to run it. Had not tried yet on MAC computers, as I do not have any.

Up till 16 presets for APL:
Another usefull feature is 16 possible presets, which could be loaded at one time. If you do not like them, just change to another 16. Switching between presets - via external switcher - the only thing I use in everyday drive. APL1 device is hidden away. 

Some of these preset positions I used to program in order to control volume of CD changer when connected to APL1 with Toslink cable. I made presets with the same FR, but at -24,-18, -12, -6, -3 dB. The idea of implementing some corrections to FR based om Fletcher-Muntzon curve is not implemented yet - still project for the future.


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## CDT FAN

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have looked around and I haven't seen any prices for the hardware yet.


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Besides automatical correction of phase during caclulations, *it has possibility to delay separate channels manually*


It can? How? 

...and it got bluetooth? is that an addon?


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



CDT FAN said:


> I have looked around and I haven't seen any prices for the hardware yet.


About $500 (edit.. at least in Europe if I do a currency conversion). Might be different in US (you always get cheaper stuff there lol)


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## themad

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Up till 16 presets for APL:
> Another usefull feature is 16 possible presets, which could be loaded at one time. If you do not like them, just change to another 16. *Switching between presets - via external switcher* - the only thing I use in everyday drive. APL1 device is hidden away.
> 
> Some of these preset positions I used to program in order to control volume of CD changer when connected to APL1 with Toslink cable. I made presets with the same FR, but at -24,-18, -12, -6, -3 dB. The idea of implementing some corrections to FR based om Fletcher-Muntzon curve is not implemented yet - still project for the future.


How do you do it? Do you have a computer in your car so you can easily change between presets?

And thanks a lot for sharing your experience with it!


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## Bluenote

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is there any info available on the APL3?


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Delay of separate channels (front left and front right) can be made using Coneq C1. While sending FIR-files to the unit there is a possibility of chosing 0-5ms delay. You can use different delay values. In my case, I have managed to move the sceen centrum to its optimal location by implementing delay difference of about 16ms between left and right. It was funny to hear the difference. When the sceen image was in place, the whole system began to "sing".

Blutooth option and apps for smartphone - that is what I miss in this device. It was nice to have, but ... Maybe it will come in future as we know for Mosconi DSPs - addon module with AMAC protocol (up to 2 Mbit/s) - fine for streaming music files up to 48/24.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Regarding APL3 - as far as I know, it is the same as APL1, but for 6 channels. Maybe I am wrong. After I have studied the vendor's site, I was not able to find more technical differences, so I believe that filosofy of the both devices is the same. 

APL3 unit was used in the champion car at EMMA Eurofinals in Zalzburg, March 2014 - 1st place in very heavy class (MM Expert).


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Here yuo can see this program, where it is possible to set different delay values to FIR-files.








Sorry for the picture quality.


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## Bluenote

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Regarding APL3 - as far as I know, it is the same as APL1, but for 6 channels. Maybe I am wrong. After I have studied the vendor's site, I was not able to find more technical differences, so I believe that filosofy of the both devices is the same.
> 
> APL3 unit was used in the champion car at EMMA Eurofinals in Zalzburg, March 2014 - 1st place in very heavy class (MM Expert).


Thanks! I was interested in the 5.1 capabilities


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## Hanatsu

Alextaastrup said:


> Here yuo can see this program, where it is possible to set different delay values to FIR-files.
> View attachment 57416
> 
> 
> Sorry for the picture quality.


Hm... dunno if I got that program.

Sent from my Samsung Galaxy S5 using Tapatalk


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sorry for the error in my previos post: delay of 16 cm, but not 16 msec, of course between left and right channels.


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## aholland1198

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Correct me if I am wrong, but you are required to purchase a measurement software separately from the hardware? 

Also, did you set time, XO via DSP prior to using the APL1?


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## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I use a normal DSP (Helix DSP) to set T/A, overall levels and crossovers. When I tested it I only adjusted T/A "somewhat right", it's possible it might have done that for you "from scratch". Never tested that to be honest. Anyway, it improved upon the setting I made and put the staging exactly correct. The measurement software and the hardware are separate products (as far as I can tell), you can use the software without the actual unit if you got a carPC for example. You don't need an advanced DSP coupled with it, it's basically required to split the signal and manage crossovers. That's why I recommended the MiniDSP boards...

Btw. Alex - Raimonds informed me about the c1 peq software, noticed the folder contained 2 executables just now. So I do have the delay program, I'll try it out as soon as possible. I have a few other tests I wanna try as well. Would be interesting to see an analysis of the *.fir file generated. Perhaps MATLAB can analyze that?


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## aholland1198

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I currently have a Helix DSP, but have plans to upgrade to the pro very soon. This sounds like a very nice product, but very odd, to me, why the software isn't included.


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## Hanatsu

aholland1198 said:


> I currently have a Helix DSP, but have plans to upgrade to the pro very soon. This sounds like a very nice product, but very odd, to me, why the software isn't included.


You should probably see it the other way around 

Sent from my Samsung Galaxy S5 using Tapatalk


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello and thanks to everyone,
Let me join!

The minimum phase correction.
APL Workshop software generates minimum phase equalizer filters by default.
You can switch on a generation of linear phase filters for some scientific purpose.
But there is no practical reason to do that because of nice properties of minimum phase correction that is doing correction on amplitude as well as on phase.
Please take a look on Quested monitor correction example to see how it works:
*delay estimation and measurement*


It is almost impossible to have useful information from on point („listening position”) measurement (TDA measurement (Quested example) is exception).
Please find attached two pictures: „listening position” measurement and power response measurement of some studio monitor.

The rotary 16 position preset switch for APL1 can be installed anywhere in a car by use of an unshielded 5 wires cable of any length (flat cable, cable for security systems).

The APL3 is simple stack of 3 PCB of APL1 to save a space. The new version of an APL1 thin stainless steel enclosure will allow stacking APL1 as it is to get more processing channels.



CDT FAN said:


> I have looked around and I haven't seen any prices for the hardware yet.


You can find useful information in this thread:
*http://www.diymobileaudio.com/forum...apl1-equalizer-system-acoustic-power-lab.html*

The APL Workshop software and APL1 unit are set of two products for solving equalizing tasks in different environments.
You can use APL Workshop just as measurement tool or with software equalizer – VST plagin APL EP1.
You can use just APL1 unit if you are able to generate FIR filter yourself. It supports wav format FIR filter coefficient files.
You do not need to purchase more than one copy of APL Workshop software if you are representing tuning studio and installing lot of APL1 units.

You do not need to analyze FIR filter generated by APL Workshop because the yellow curve already represents it fully. The FIR filter file format used by APL is proprietary, closed format. I can convert it to any specific format you like on order.
But anyway, you can check how accurately APL1 unit creates that curve by measuring just unit with respective FIR file uploaded to it…

Anyway, please feel free to ask me more questions!

BR,

Raimonds
Acoustic Power Lab :: Home


----------



## Bluenote

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So is the APL3 discontinued? Or is it the same price as 3 APL1's?


----------



## Hanatsu

Ok. Then I won't attempt to read it. One question, the other files... the .*DAT which can be opened in notepad. What different data do they represent, I assume that PR is power response.

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right, and PRS - power response smoothed on your own demand from 1/3 to 1 octave


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Bluenote said:


> So is the APL3 discontinued? Or is it the same price as 3 APL1's?


APL3 is still available on order. It costs little bit more than 3 APL1 due to specific production.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Got a question how to load the VST plugin in foobar2000. Here's how:


----------



## Jcharger13

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was the one that had troubles with the VST plugin. Thanks Han. 

I figured out what was going on. I didn't have a VST plugin drop down in my components like Han does in the example above. I originally thought you just put the APL VST plugin into the component file of foobar but foobar wouldn't recognize the plugin. I finally figured out I needed a VST plugin just to be able to load the VST for APL that's called (Foobar 2000 VST 2.4 adapter). Now all is working well.


----------



## CDT FAN

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was looking at the flat response curve and how it was able to remove the null. If a null is caused by certain frequencies cancelling each other out (I guess that is the opposite of a resonance frequency), then how does it adjust the level to counteract that?


----------



## Hanatsu

CDT FAN said:


> I was looking at the flat response curve and how it was able to remove the null. If a null is caused by certain frequencies cancelling each other out (I guess that is the opposite of a resonance frequency), then how does it adjust the level to counteract that?


It fixes areas which are minimum phase. So phase cancellations between drivers will not be much of an issue. Modal dips can't be EQed, but you can lower the adjacent frequencies to gain a 'flat' response. Doing it this way will cause a higher demand of power at the modal dip though. In my example there were major peaking at 100Hz and 50-60Hz which made it look worse than it was.

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Modal dips can't be EQed, but you can lower the adjacent frequencies to gain a 'flat' response......
> 
> Sent from my Samsung Galaxy S5 using Tapatalk


.....and since you're now attenuating a range, everything else will need to fit in with this range to keep tonal balance. Each null that one addresses means you're cutting across ranges. 

On the power of eq......One doesn't need to 'treat' every null. Deep and narrow nulls are less of an issue. Shallower nulls spread over a 1/3 of an octave or more are a bigger issue specially in the mid range. More than the units ability to flatten out the response, I would value the L/R balance across 2000 odd points. A eq at 1/6 octave with nice slider controls for each channel/side (assuming you stack these units), would be the cherry on the cake. Of course 1/3 to 1/6 would be a two year learning curve


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> .....and since you're now attenuating a range, everything else will need to fit in with this range to keep tonal balance. Each null that one addresses means you're cutting across ranges.
> 
> On the power of eq......One doesn't need to 'treat' every null. Deep and narrow nulls are less of an issue. Shallower nulls spread over a 1/3 of an octave or more are a bigger issue specially in the mid range. More than the units ability to flatten out the response, I would value the L/R balance across 2000 odd points. A eq at 1/6 octave with nice slider controls for each channel/side (assuming you stack these units), would be the cherry on the cake. Of course 1/3 to 1/6 would be a two year learning curve


All correct. High Q (narrow) dips/peaks are less audible than low Q (wide). Overall response (summed) isn't THAT important to get 100% either, this is responsible (no pun intended) for overall tonal balance. The L/R response however is far more important as it largely dictates how the system stages, here we have far more use for an accurate 'multipoint' FIR EQ. Any dip or peak that isn't consistent from left to right channel will cause the stage to either side. Same with absolute phase, which is inaudible. Relative phase is not however. Having phase correction (phase EQ) is invaluable in the ITD-range (below 1600Hz or so) because it can keep the center/staging calm even if the relative group delay (magnitude/phase relation) is off. 

Since APL does all the corrections automatically the amount of EQ you want/need to adjust yourself is not that big actually. I found 2 or 3 areas in the initial run of APL that I manually applied some minor correction to. By all means, this is far less than I usually correcting for when fine tuning after measuring using the 'traditional method'. 

Again, you already know this. You just so anal about doing everything manually xD


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Sorry for the error in my previos post: delay of 16 cm, but not 16 msec, of course between left and right channels.


I haven't tested it yet but it seems from your screenshot that it can be adjusted 0-5ms. If so, 5ms ~ 170cm. Correct me if I'm wrong...


----------



## CDT FAN

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The more I read about the details, the more I realize that I don't quite understand. I am going to download the plugin and see what I can do with it.

I have a laptop with foobar, a Dayton Audio iMM-6 Calibrated microphone, a head unit that has a line level input and the soon to be downloaded plugin. It there anything else I need?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hanatsu,
Both yes and no. If 1 ms at normal atmospheric pressure corresponds to appr. 34 cm (little bit more, indeed), so you are right. You can backup fir-flter with the max delay of 4,797 ms.
It will be a new filter: ***-fir_4,797ms. Then you can use this new file to delay it further. New file name will be: ***fir_4,797ms_4,797ms. I mean that the last one has a delay of 4,797 x 2, which is about 350 cm. I can not see any restrictions for this process. Going to ask Raimonds about this issue.

I'm now trying to tune my front again as some things have been changed (HPF, LPF, crossover frequencies and the most important - frequency response of the both fronts). If I would still use old APL-corrections made onr year ago, the sound will be more bright than necessary. I will for sure make some tests of the delayed files with TDA software.

Regarding time alignment, phase control etc. - to my opinion the majority of people underestimate its importance as they think it is not audibe. I could easily hear the stage center moving by just applying different delays between left and right speakers. It is kind of rotating image, which has its own optimal position. Do not forget about midbass and sub. For some complicated subs it is required quite siginificant optimization ion the time domain (much more than 5 ms). Try to spend your time analysing results of tests with TDA - sure you will be surprised. By the way, the latest version of this soft: TDA 9.0 gives you even more information - distortion analysis.

When you open graffs in TDA, it is possible to use a cursor for determination of exact values needed to be corrected. APL's accuracy is rather high (compared to fx. min. delay steps in my HU - 0,1mc (3,4 cm)).


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Hanatsu,
> Both yes and no. If 1 ms at normal atmospheric pressure corresponds to appr. 34 cm (little bit more, indeed), so you are right. You can backup fir-flter with the max delay of 4,797 ms.
> It will be a new filter: ***-fir_4,797ms. Then you can use this new file to delay it further. New file name will be: ***fir_4,797ms_4,797ms. I mean that the last one has a delay of 4,797 x 2, which is about 350 cm. I can not see any restrictions for this process. Going to ask Raimonds about this issue.
> 
> I'm now trying to tune my front again as some things have been changed (HPF, LPF, crossover frequencies and the most important - frequency response of the both fronts). If I would still use old APL-corrections made onr year ago, the sound will be more bright than necessary. I will for sure make some tests of the delayed files with TDA software.
> 
> Regarding time alignment, phase control etc. - to my opinion the majority of people underestimate its importance as they think it is not audibe. I could easily hear the stage center moving by just applying different delays between left and right speakers. It is kind of rotating image, which has its own optimal position. Do not forget about midbass and sub. For some complicated subs it is required quite siginificant optimization ion the time domain (much more than 5 ms). Try to spend your time analysing results of tests with TDA - sure you will be surprised. By the way, the latest version of this soft: TDA 9.0 gives you even more information - distortion analysis.
> 
> When you open graffs in TDA, it is possible to use a cursor for determination of exact values needed to be corrected. APL's accuracy is rather high (compared to fx. min. delay steps in my HU - 0,1mc (3,4 cm)).


I agree...

If correcting for group delay in the subwoofer frequencies, we either require channel independent delay (not possible with 2ch), which means more than 1 board of APL. 

OR

Can it do frequency dependent delay to correct a specific frequency range? If so, how's that done manually? In TDA? I'm hopefully trying out TDA this week


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



CDT FAN said:


> The more I read about the details, the more I realize that I don't quite understand. I am going to download the plugin and see what I can do with it.
> 
> I have a laptop with foobar, a Dayton Audio iMM-6 Calibrated microphone, a head unit that has a line level input and the soon to be downloaded plugin. It there anything else I need?


Except the APL software... that's it.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I agree...
> 
> If correcting for group delay in the subwoofer frequencies, we either require channel independent delay (not possible with 2ch), which means more than 1 board of APL.
> 
> OR
> 
> Can it do frequency dependent delay to correct a specific frequency range? If so, how's that done manually? In TDA? I'm hopefully trying out TDA this week


The APL Workshop measurement is showing only "real" dips (not caused by interference) and we must deal with them by ordinary means but not with a direct equalizer use at first.
We should try to find real problem causing that dip and remove it by basic tuning.
Usually such dips are caused by improper crossover tuning (including out of phase). And they are non minimum phase. The correction of non minimum phase problem (do not have ringing in its impulse response) with minimum phase equalizer (will have ringing in its impulse response) is not the best to do.
Only in the case when we can not do anything with a basic tuning we should use an eq.
And we may need to reduce a deep of that dip by 2 times (manually) to get best audible result. That was tested on problematic studio monitors where crossover bands did not overlap as needed - simply did not reach each other making huge dip at 1 kHz.









“Can it do frequency dependent delay to correct a specific frequency range?”

Yes, but it is based on TDA measurement and must be aplayed “manually” (no ready to use tool) after all work on “amplitude” is done.
Returning to Quested monitor example - *delay estimation and measurement*


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds,
Does it mean that if there is a dip of -10dB, correction for avoiding it will be -20 dB for the best results?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Raimonds,
> Does it mean that if there is a dip of -10dB, correction for avoiding it will be -20 dB for the best results?


It will be -5 dB ...


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

An issue about use of two soundcards ( one for playback, another for recording) become actual.
Two different clocks are working in such case. And we will have time compression or expansion in our measurement data that depends of which clock is faster. Therefore the actual set of soundcards must be tested for that issue. APL Workshop Impulse Response tab is drawing all IRs in one graph. All of IRs must be on 5 ms with they max spike. 










In case of time compression or expansion we will see IRs covering some time interval. It is ok if this interval goes under window (green curve). 










If no, we have a problem.


















The workaround for this is to accent first or last measurement (put the microphone more closely to the speaker/tweeter) that depends which clock is faster and you must find it by an experiment.


----------



## Brian Steele

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


>


I'm curious as to how it removed your 70 Hz "dip". Did it just decrease the output above and below that dip to flatten the response?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I agree...
> 
> If correcting for group delay in the subwoofer frequencies, we either require channel independent delay (not possible with 2ch), which means more than 1 board of APL.
> 
> OR
> 
> Can it do frequency dependent delay to correct a specific frequency range? If so, how's that done manually? In TDA? I'm hopefully trying out TDA this week



I do not think TDA is able to make frequency dependent delay manualy, But is this necessary for junction of two sources (midbass and sub, for example)? Of course it will be nice to have ...
My sub is not connected to APL1 - only two front channels (2way-passive with its own crossover). I delay front left channel (quite a lot) in order to fit to the response from the sub (more than 25 ms). The same - with the pair: front right channel + sub. And it works fine, as sceene is placed just where it shoud be. No other time alignment adjustments are needed.


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## Hanatsu

Brian Steele said:


> I'm curious as to how it removed your 70 Hz "dip". Did it just decrease the output above and below that dip to flatten the response?


Yes as I said, there was in fact large modal peaks above and below the "dip" 

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello,

As customers requested, the new thin, stainless steel enclosure become available for APL1 RCA. Dimensions 178 (DIN) x 144 x 22.5 mm


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Great news! Thanks. Even the first model of APL1 was not rather thick after my mind, but to get it smaller makes this unit more portable with the increased flexibility for installation.


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## Hanatsu

Looks awesome ^^

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Fast1one

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have a convertible which is a bit challenging because the response changes drastically with the top up and down. Luckily, I drive the car with the top down 80-90% of the time. 

For that 10-20% that I have my top up, is it possible to do two separate calibrations and switch on the fly?


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> .
> 
> The rotary 16 position preset switch for APL1 can be installed anywhere in a car by use of an unshielded 5 wires cable of any length (flat cable, cable for security systems).
> 
> 
> Anyway, please feel free to ask me more questions!
> 
> BR,
> 
> Raimonds
> Acoustic Power Lab :: Home


Is this 16 position switch included? if it's not included do you have a link. i'd like to see what this looks like. Thanks


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yes, it is possible to do two separate calibrations (and not only two) and then switch on the fly. The switching takes about 1 second. The switching process is clear – without pops, noise or muting.
The switch is this:
BCKS1001 - LORLIN - SWITCH, ROTARY, HEX, NO STOP, IP65 | Farnell element14
The switch and flat cable of length you need are included in “16 preset” option.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Yes, it is possible to do two separate calibrations (and not only two) and then switch on the fly. The switching takes about 1 second. The switching process is clear – without pops, noise or muting.
> The switch is this:
> BCKS1001 - LORLIN - SWITCH, ROTARY, HEX, NO STOP, IP65 | Farnell element14
> The switch and flat cable of length you need are included in “16 preset” option.


Where do you connect the cable btw?

There's a 5-pin connector on the board somewhere? Interested in making a switch myself.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I've got my 16-position switch included in the package from Acoustic Power Lab along with APL1 unit. In my car it is installed now near the cigaret lighter - so it is easy to switch when driving.

Normally I use no more than 3-4 presets (one with "dispersion" solution for the tweeters). 6 positions are programmed for volume control when the CD-changer is connected to APL1 with the optical cord (from-24dB till -6dB).


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> I've got my 16-position switch included in the package from Acoustic Power Lab along with APL1 unit. In my car it is installed now near the cigaret lighter - so it is easy to switch when driving.
> 
> Normally I use no more than 3-4 presets (one with "dispersion" solution for the tweeters). 6 positions are programmed for volume control when the CD-changer is connected to APL1 with the optical cord (from-24dB till -6dB).


Does the same 16 position switch also control the inputs?

Are you using another DSP to control crossover so and TA? ( Is your system active?)
Thanks


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You can't switch inputs with it. 16 position switch is for changing between 16 presets, in other words - different target curves. Apl1 is only two channel device, but could be used together with every dsp. One of examples - aplaudio on Facebook. Here you can see the two diagrammes of the install in the champion car (2 first places in Eurofinals in 2014). 

In my present car I am running passive front with TA from the HU. Almost finished a new passive 3way crossover (my own design) for new install.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Some good questions:


> - Can I use digital in and provide an analog (RCA) output? In other words, are the inputs and outputs assignable?
> - If I run an active setup, what should I look for in a processor? Is time alignment and level adjustment sufficient or would more EQ help? Or should I just leave it flat and let the APL1 do its thing?
> - What is involved for the measurements for the driver seat position? In other words, how many measurements?


1. All three outputs (analog, SPDIF, TOSLINK) are working in parallel and simultaneously.
The active input depends on fact is digital carrier present on digital input or not.
If yes - digital input is working. If not - analog input is working.
You can use APL1 as commutation unit between two sources - analog one and digital one such way.

2. You should tune up your processor as accurate as possible. The TDA software is good helper for this. *http://www.diymobileaudio.com/forum...ain-analysis-measurement-software-review.html*
You must critically evaluate FR curve measured by APL Workshop also. Are there possibilities to improve it by more accurate processor tuning?
Please keep in mind that it is not good practise to use EQ to correct processor tuning mistakes. Therefore the TDA was developed.

You should leave flat processor's EQ part and let the APL1 doing all eqing tasks.
The switching on even one of processor's parametric dramatically degrades quality for most of ordinary processors ...

3. It depends on your driver directivity. I have seen setups where directivity issues was not presenting and was not need to work on driver seat position.
In case of strong directivity you should run additional measurement to deal with that directivity.
You can chose number of measurements 25 ...50 ...100 ...200. But even 200 takes just 1 minute ( 3 measurements per second). The 50 ... 100 usually are sufficient.


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Some good questions:
> 
> 3. It depends on your driver directivity. I have seen setups where directivity issues was not presenting and was not need to work on driver seat position.
> In case of strong directivity you should run additional measurement to deal with that directivity.
> You can chose number of measurements 25 ...50 ...100 ...200. But even 200 takes just 1 minute ( 3 measurements per second). The 50 ... 100 usually are sufficient.


For the on-axis measurement, is it being used as additional measurment or as the corrective ?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

On-axis measurement is used as a correction to the total EQ, not as a separate setup


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Im interested in trying this product, APL1. I think I would like 6 channels of control, 2 fro tweeters, 2 for midrange and 2 for midbass. Is this recommended Raimond?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



deeppinkdiver said:


> Im interested in trying this product, APL1. I think I would like 6 channels of control, 2 fro tweeters, 2 for midrange and 2 for midbass. Is this recommended Raimond?


Such a powerful setup will be hard to take under control : )))


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> For the on-axis measurement, is it being used as additional measurment or as the corrective ?


Hello,

I will try to explain how to use additional „near on axes” measurement to make the correction result more accurate for „on axes” position in case when loudspeaker has a pretty strong directivity in some frequency band. 

1.	You should make an „ordinary” Power Response measurement by collecting measurement points in full wide angle or volume.










2.	You should make an additional „near on axes” measurement by collecting measurement points in relatively small square, about 20 x 20 cm, on axes.










3.	Let’s calculate the curve that is representing an effect of directivity by subtracting our first curve from the second one by setting the first one as „correction” for the second one.










4.	Let’s smooth it










5.	Let’s remove LF part by flatting it (by use of „Limiter”).










6.	Let’s make the correction for first measurement by adding the smoothed and edited directivity curve as „correction” for first measurement but by using „INV” check box because we need to add it, not subtract.










Now we have the measurement curve and, of course, the equalizer curve that do not boost up frequencies that are emitted in narrow beam on axes.


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Such a powerful setup will be hard to take under control : )))




I understand this would be a very difficult setup, what do you recommend. If I want to run completely active, tweeters midrange and midbass running on separate channels. Should I only run APL on midrange, I would not think this would give positive results. 

Perhaps I should try to run 3 way passive in order to effectively utilize the benefits of APL..


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



deeppinkdiver said:


> I understand this would be a very difficult setup, what do you recommend. If I want to run completely active, tweeters midrange and midbass running on separate channels. Should I only run APL on midrange, I would not think this would give positive results.
> 
> Perhaps I should try to run 3 way passive in order to effectively utilize the benefits of APL..


The most important benefit from „active” is that you can go to the result „straightly” – 1) measure and 2) apply. In a „passive” version you will have to run infinite loops of tuning of your passive crossover.


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It would seem to me the main benefit comes from how one ALP1 works for the entire frequency range. Its ability to smooth out crossover points being a very big part of what it does.
I'd think you'd want all your source signal to go through one ALP1, then to your DSP for Time Alignment and crossover.


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Im wanting to run active and would like to use the APL. It does not make sense not to apply it at all frequencies as Fishman also said. 

From the APL into my DSP and then on to amplifiers.

Raimond my question to you sir is what product do you offer to apply APL to my build across all Channels that will be controlled in an active manner. Do I need 3 or 4 of the 2 ch devices? Is there a 6 or 8ch option? 

I will have one amplifier per driver in my truck. Each mono amplifier on tweeters, midbass and midrange will be fed a signal of L/R accordingly.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

i would love something that has FIR filters and can use strictly for crossovers.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



deeppinkdiver said:


> Im wanting to run active and would like to use the APL. It does not make sense not to apply it at all frequencies as Fishman also said.
> 
> From the APL into my DSP and then on to amplifiers.
> 
> Raimond my question to you sir is what product do you offer to apply APL to my build across all Channels that will be controlled in an active manner. Do I need 3 or 4 of the 2 ch devices? Is there a 6 or 8ch option?
> 
> I will have one amplifier per driver in my truck. Each mono amplifier on tweeters, midbass and midrange will be fed a signal of L/R accordingly.


The recommendations earlier in the thread are to let the apl do its work in stereo.....as in directly after the source, either digitally or via rca.....then allow your processor to split the signal with crossovers and allignment. Then you only need one two channel apl unit for the entire system.


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

^ sorry I missed that.. I would not have asked.

Thank you sir! This has me thinking..


----------



## Guest

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

SO what exactly does the APL unit do ?

Is it just a measurement device or does it provide some form of filtering/manipulation ?


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SQ_TSX said:


> SO what exactly does the APL unit do ?
> 
> Is it just a measurement device or does it provide some form of filtering/manipulation ?


As i understand, it provides quick Auto EQ (4096 bands of it), and some minor phase correction for a near perfect tune. 
Post 11 & 13 seem to explain it best to me.


----------



## Guest

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So no real need to EQ after the unit ?


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SQ_TSX said:


> So no real need to EQ after the unit ?


If I understand correctly.

Set your crossovers, and time alignment, with your DSP. 
Then let the APL1 do the rest. 
Then enter your desired eq curve options, up to 16 tunes for the remote control knob.


----------



## Guest

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So, you enter your desired final EQ curve into APL software.... The processor then creates that curve in real time.... ?

Very nice...


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The good question: 


> Why is a FIR based EQ better than others ?



Because you can create any curve you like and can do that instantly.
With ordinary parametric EQ you can only approximate to curve you need. And you may spent hours for that.
FIR also allows create phase/delay curves independently from an amplitude curve.
And FIR has much higher processing quality than ordinary IIR.
You can sum any number of curves (parametrics) and run them in one FIR filter.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello,

The brand new APL1s HR unit becomes available. Half rack, 117 dBA, 96 kHz, 0.0003%, 0.12 ms …

Acoustic Power Lab :: APL1s


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds,

What is the difference between the APL workshop and TDA EQ?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> Raimonds,
> 
> What is the difference between the APL workshop and TDA EQ?


The APL Workshop software is based on Sound Power evaluation and it takes special measures in some „not simple” cases – 1) tweeters have serious directivity issues 2) the complex sub is used and it is introducing very large delay in its band. The solution for first case is published few posts higher. You should use large Time Window – 100 ms, 200 ms (and may be curve editing) for second one.
The APL TDA EQ software is exploiting incredible time resolution of TDA processing and is free from two drawbacks of APL Workshop mentioned. But it is not as stable as Workshop. It was developed as a tool for near field application that is free from very early reflections. The car environment is opposite. It has very serious early reflections that can ruin the result of TDA EQ work. Therefore it is possible to get very exceptional result by use of TDA EQ in car environment and it is possible to go into treble. Some examples for a car environment.
1.	A pretty nice result. First image – before eq, second – after EQ



















2.	A nice result also but we can see an excessive phase added on crossover points caused by an improper initial tuning of crossover.




















3.	A problematic result. Midrange and HF drivers have strong side lobes of directivity (not clear piston motion, surface waves on driver membrane) that are „ caught” by early reflections and than is „amplified” by TDA EQ.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So what's the difference between this and say dirac fir example?

Do they achieve the same result through different means or are there different functions happening here?


----------



## cajunner

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

we need (and by this, I mean I need) a price quote and a retail store option, for everything necessary to implement this awesome technology.

I assume I will need a good microphone, calibrated by elves...

then I will need to spring for a software package of at least 3 component parts, at least one of which is not from the same people who sell this processor?

and the new version, I assume, is now more expensive than before?


at 400 Euro, for just the hardware, that's about $600 US?

so a good mic, at the bottom is the ECM-8000, calibrated, will cost at least 150?

then the computer software is near 1000?

and the computer that runs this admirably, would set me back at least 200?

add in the extra software (TDS) that doesn't come with, and we're looking at more money?

just how much, is everything together to move into FIR filter product, without having to buy and learn how to use a CAR PC?


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Car PC would be stealth, on screen real time results. I've discussed that option with Raimonds but it was some time ago. I just so happen to have a e3io indash Custom PC id let go at a great price if interested.


Im also interested to know exactly what all is needed to run this in car and would it work on an Ipad?


----------



## cajunner

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



deeppinkdiver said:


> Car PC would be stealth, on screen real time results. I've discussed that option with Raimonds but it was some time ago. I just so happen to have a e3io indash Custom PC id let go at a great price if interested.
> 
> 
> Im also interested to know exactly what all is needed to run this in car and would it work on an Ipad?


I suspect it takes a decent processor to run this.

if the Ipad has the program that allows it to run VST plug-ins, whether Foobar or whatever, then it should be able to run this?

you'd be buying the software suite, which is higher cost but could you improve on the new hardware?


I would imagine that having a Car PC already is the way to go, otherwise buying the hardware makes more sense?


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have the room for a full Ipad so depending on oem integration that is the route Im headed. Ill run the suite if I can per on the Ipad. If it makes more sense to run the hardware and can view results on the Ipad ill do that instead.


----------



## cajunner

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

my guess is that the iPad is a full-blown computer, with enough processing power to run this software but only in 2 channel, or a USB sound card slash, break-out box would be needed to go with 5.1 processing. I believe that you can do everything in Foobar or whatever passes for VST plug-in compatibility with Apple/Mac software, and if not, at the very least, within a shell that runs in Windows architecture?

I don't have any of this stuff down pat, but it makes sense to me to possibly use an external sound card with the iPad and a program that costs a bit of money to use the VST plug-ins.

I imagine it would be easier with a tablet PC that runs Windows 8.1, then you'd have more compatibility and possibly less lag based on how much processor the programs use when in operation...

it would suck to have all the good **** working and when you go to play a video on the in-dash iPad the thing bogs down and goes to buffering every few seconds...


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



cajunner said:


> *we need (and by this, I mean I need) a price quote and a retail store option, for everything necessary to implement this awesome technology.*
> 
> I assume I will need a good microphone, calibrated by elves...
> 
> then I will need to spring for a software package of at least 3 component parts, at least one of which is not from the same people who sell this processor?
> 
> and the new version, I assume, is now more expensive than before?
> 
> 
> *at 400 Euro, for just the hardware, that's about $600 US?*
> 
> so a good mic, at the bottom is the ECM-8000, calibrated, will cost at least 150?
> 
> then the computer software is near 1000?
> 
> and the computer that runs this admirably, would set me back at least 200?
> 
> add in the extra software (TDS) that doesn't come with, and we're looking at more money?
> 
> just how much, is everything together to move into FIR filter product, without having to buy and learn how to use a CAR PC?


The bottom line price would be nice. 
I'm a bit doubtful i could find any shops in my area that could/would be able to help with the setup for a reasonable price.


I see you're behind on the current conversion rates also. 
Now $400 EUROS is $450 US dollars. 
Overseas purchases are looking more attractive lately


----------



## cajunner

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



1fishman said:


> The bottom line price would be nice.
> I'm a bit doubtful i could find any shops in my area that could/would be able to help with the setup for a reasonable price.
> 
> 
> I see you're behind on the current conversion rates also.
> Now $400 EUROS is $450 US dollars.
> Overseas purchases are looking more attractive lately


sweet!

now I can call up my Sevruga supplier, Petrossian and get a couple of tins sent out, chop chop..



as for the local shop being able to handle Raimonds and his wunderbar/kind doo *** diddy two stop, not likely...

however, anyone slips into the install bay and has one of these installed and working, will probably garner much attention...

with that display of charts, people will say "is that a waterfall plot? who makes this, I never saw this before, is this really mapping the interior, you say it's an impulse response software, can you really make the left and right phase perfect, together..."


or, maybe not...


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Werd caj....I'm with you on all you've said. I'm very curious about this system and how I might apply it to my own car.......but details are few around total cost......and what all is needed to fully implement it and all its functions.......maybe it's language barriers holding us back?


----------



## cajunner

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Werd caj....I'm with you on all you've said. I'm very curious about this system and how I might apply it to my own car.......but details are few around total cost......and what all is needed to fully implement it and all its functions.......maybe it's language barriers holding us back?


I think that's part of it.

also, I think that the advanced nature of this proprietary device, is hitting a wall of novelty in the thought process.

people don't have access to a system that uses mapping to create a response, because that seems to be new.


the MS-8 does it for it's own software generation, and has sophisticated filters run according to algorithms, but this thing appears to use more of the car's test points than the binaural mics on the headset of the MS-8.

So a lot of what this thing is doing is the full version, and MS-8 seems to be using a lite, version that is low on corrective input from the user.

I believe both use 4096 taps, or is that Audyssey....

I don't know.

So it gets deeper into the corrections than MS-8, or MS-2, for that matter except that it is more like MS-2 in that it's just a 2 channel product.

If you buy the software and have the computer/ sound card, I suspect the opportunity exists to save money and use several '2 channels' together in a split, or crossed-over system?

If the opportunity to rent the software long enough to program a car to one's liking would be offered, the hardware might sell a lot better.

although with the bunch of tweaker sluts that frequent this place, the software rental would end up being like that library book that you can't seem to return to the library...

always trying out this speaker or that tweeter, each time needing the software to do it's thing, a pillar or kick, dash pod or sails, nope...


gonna have to bundle that software with the hardware for less than 800 American, US dollars.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So us it like dirac or opendrc??


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



madcowintucson said:


> So what's the difference between this and say dirac fir example?
> 
> Do they achieve the same result through different means or are there different functions happening here?


Just FIR is not giving you any benefit. It is a powerful DSP tool capable to do anything you like or need. But you must know what you like. And you must know how to supply that to FIR. Everything is about how to prepare FIR filter.

Lot of developers are following a trend of digital room correction. With hope, that the predistortions, introduced by their DRC equalizer, will be neutralized by distortions of the room. But this still remains as hope. Our hearing, developed by millions of years, is capable to separate (localize) the sound source (party effect). And the distortions, introduced into the sound source with hope to correct the room, will remain as distortions. The experience shows that the predistortion-distortion concept (correction, equalizing) works only for the sound source. You must know problems of your sound source (loudspeaker) and than you can create predistortions that will be neutralized by distortions of your loudspeaker. And everything is about how to know (measure) what loudspeaker is doing. The two concepts, that “extract” properties of the loudspeaker, may help – 1) the measurement in power domain 2) the use of very high time selectivity.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So you are saying that your unit does the speaker and not the room.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



madcowintucson said:


> So you are saying that your unit does the speaker and not the room.


Actually, the unit is doing FIR processing and everything depends what we supply to the unit.
If we supply such curve, we and unit will do "drc".










If we supply the speaker’s curve measured in Power domain, we will do the speaker.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Regarding pricing - you get actually what you pay... SQ costs money. Good sound demands more money. Nothing is free of charge under the sun (except sun rays, of course). For me it was a significant amount of money to be spent (both hard and software), but I never regret this purchase. It was my best investment in caraudio. Before comparing prices for APL1-pack with others on the market, one should find out what the compatitors can. Sorry, but I could not find any compatitor, capable for 4096 filters. My previous experience with up till 31 parametric bands was not successful - a lot hours spent for tuning (mainly - night hours), but result was not good enough for me before I met APL1 option.

Concerning software - I used it not more than 15-20 hours last year (different setups etc). It could be more attractive for potential buyers to have a time limited licence for let say one month or 30 starts, which could be bought cheaper and to keep the full price for installation companies. 

Yes, I agree that APL1 is not the cheapest solution. But on the other hand with the APL1 you could save money on loudspeakers (like in my case). It will tune low-cost sets to produce a rich sound you never could expect. Sounds promissing? Yes, but I would not compare this device (do not forget - protected with patents) with ordinary sound processors on the market today. If you need some new smart features like bluetooth, active crossover, wireless remote control, big touch screen - there are some good opportunities today. But if you seek the device that can give you exceptional sound quality in the car - APL1 is your choice. I hope this explanation can help to understand what kind of device is designed by Raimonds.

Up till now I have not seen any negative review of this unit. I am the first owner of it in Scandinavia (already 2 years) and can only exchange my positive experience. More over - it is rather durable and stable - no issues at all during this period of time.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So what, basically optical in to the apl1, then optical out and on to the main dsp where the crossovers and various other things operate?? Do I have this right?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



madcowintucson said:


> So what, basically optical in to the apl1, then optical out and on to the main dsp where the crossovers and various other things operate?? Do I have this right?


Yes, as usually with any new thing in the signal path – optical output of head unit to optical in of APL1, optical out of APL1 to optical in of DSP. But this is simplest thing of all process ...


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Kiss man, kiss lol. So basically like the dirac or drc, but you are saying your unit is more effective. I like the idea of a 12 volt ready unit then I don't have to mess around with conversion. So what are your recommended mics again??


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



madcowintucson said:


> Kiss man, kiss lol. So basically like the dirac or drc, but you are saying your unit is more effective. I like the idea of a 12 volt ready unit then I don't have to mess around with conversion. So what are your recommended mics again??


Any measurement mic will work. It is not critical. Of course, it is nice if you have a calibration curve of your mic. But, if you can borrow the reference grade mic from your friend, you can make a calibration curve of your mic yourself.


----------



## subterFUSE

I have 2 optical sources in my car.

1. mObridge DA1
2. Audison Bit Play HD

Both have variable volume embedded in the optical signal. MObridge uses the OEM head unit volume knob and Bit Play has a wireless remote.

I still have a volume controller for my Helix DSP Pro so I don't use the volume on my sources.

Just curious if the APL will work in my car? Or would I need 2 of them because I have 2 optical sources?


Sent from my iPhone using Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You could have optical signal switch and use only one APL1


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I don't write on this forum that much anymore, but I thought to stop by and applaud Raimonds for this unit. With a completed system and a proper setup my system sounds better than ever. I'm not afraid to say that it's now at a point where it competes with the best systems I've heard.

It works perfectly with no issues at all so far and everyone I demoed my system for were impressed primarily by the imaging but also the neutral sounding tonality. I have done lots of measurements and research related to the APL unit and will present it later this summer. I have no time at the moment to process it all.


----------



## Bluenote

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Would the APL-1 be redundant in an MS8 setup? Redundant meaning the fact that MS8 sets an EQ curve and then having this set one also...


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimond. I am ready to purchase your APL1 and would like to ask a couple more questions to confirm my needs/purchase. How do you prefer I contact you sir?


----------



## Bai Qui

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I've been following this and the other thread on the APL1 for a while, glad to see people asking the questions I've been wondering. I'm piecing my system together and my question basically boils down to exactly what I need in order to use the APL1. My setup will be pretty simple, two way front and a sub, all running active.

From what I've gathered, I would run the signal from the source into one 2-channel APL1, into a dsp which will do the crossovers and TA, then onto the amps and speakers.

To use the APL1, I need a computer, sound card, calibrated mic, the APL1 and the APL Workshop software. And I would need to enter the target curve. 

Looking at the APL website, the APL1 and APL software together runs 830 Euros or ~$920.

This all sound about right? You'll have to excuse me if this is a dumbass question, just looking to confirm what I'm figuring I need.


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

hanatsu and alex,

Do you have a reference target curve that you can share to me, because as of right now i am setting this apl1 unit?

I am starting the setting with APL TDA to clarified and set the basic setting in my PS8, now i get to the point to start playing around with the apl1rca

Thx


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Bai Qui said:


> I've been following this and the other thread on the APL1 for a while, glad to see people asking the questions I've been wondering. I'm piecing my system together and my question basically boils down to exactly what I need in order to use the APL1. My setup will be pretty simple, two way front and a sub, all running active.
> 
> From what I've gathered, I would run the signal from the source into one 2-channel APL1, into a dsp which will do the crossovers and TA, then onto the amps and speakers.
> 
> To use the APL1, I need a computer, sound card, calibrated mic, the APL1 and the APL Workshop software. And I would need to enter the target curve.
> 
> Looking at the APL website, the APL1 and APL software together runs 830 Euros or ~$920.
> 
> This all sound about right? You'll have to excuse me if this is a dumbass question, just looking to confirm what I'm figuring I need.


IMHO
That is basicaly what you need to used this system


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I have 2 optical sources in my car. ...


It is possible to add second optical input for APL1 (plastic) that can be managed by a relay and remote switch.



Bluenote said:


> Would the APL-1 be redundant in an MS8 setup? Redundant meaning the fact that MS8 sets an EQ curve and then having this set one also...


You should switch off any other eq because (in most car audio cases) they are degrading signal (poor processing). But if you leave as is, no problem also.



neoysj said:


> hanatsu and alex,
> 
> Do you have a reference target curve that you can share to me, because as of right now i am setting this apl1 unit?
> 
> I am starting the setting with APL TDA to clarified and set the basic setting in my PS8, now i get to the point to start playing around with the apl1rca
> 
> Thx


The "mp1" should be used for basic start. Next will depends on your preference. You can find it by use of parametric EQ.



neoysj said:


> IMHO
> That is basicaly what you need to used this system


Right!



deeppinkdiver said:


> Raimond. I am ready to purchase your APL1 and would like to ask a couple more questions to confirm my needs/purchase. How do you prefer I contact you sir?


Questions should go here. 
Please use the Contact or Buy form on Acoustic Power Lab :: Home for a first contact.


----------



## subterFUSE

I think the APL1s makes more sense for me because of the higher sample rate matches my sources and DSP sample rates.

Can APL1s be used in a car?


Sent from my iPhone using Tapatalk


----------



## deeppinkdiver

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I think the APL1s makes more sense for me because of the higher sample rate matches my sources and DSP sample rates.
> 
> Can APL1s be used in a car?
> 
> 
> Sent from my iPhone using Tapatalk




Yes sir. That is what I am looking at it for is car use. It is installed in a few guys vehicles that compete over seas and do very well with them. I will be getting my order in asap.


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I think the APL1s makes more sense for me because of the higher sample rate matches my sources and DSP sample rates.
> 
> Can APL1s be used in a car?
> 
> 
> Sent from my iPhone using Tapatalk


Yes, the APL1RCA is the stainless steel enclousure version that is perfect tobe installed in the car.
I, myself, right now installing this device in my car and in the stage of trying different setup


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I think the APL1s makes more sense for me because of the higher sample rate matches my sources and DSP sample rates.
> 
> Can APL1s be used in a car?


The four year history of APL1 unit is showing that it serves almost all demands for use in a car. 
The APL1s unit was planned for studio and live sound as it adds more freedom but for serious additional costs. And it does not have power input ready for car environment (7.5 V). It will be hard to have a return from such investment in a car installation.


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## subterFUSE

If using the mobridge DA1 preamp as the optical digital source, the OEM volume control can be retained. This is possible because the mobridge has variable volume embedded in the optical signal.

If the APL1 is used after the mobridge via optical, will the volume still be controlled at the OEM head unit?

Or does the APL1 need a constant volume signal fed into it and then a DSP with volume control be required after the APL1 to adjust volume?


Sent from my iPhone using Tapatalk


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What I have been doing is cell phone aptx bluetooth to optical converter=cheap. Then optical into behringer. So I could swap out the behringer stuff for an apl1. Then on from there into optically into a dsp. My cell phone is what I listen to most on milk or slacker it sounds good enough for me.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> If the APL1 is used after the mobridge via optical, will the volume still be controlled at the OEM head unit?
> 
> Or does the APL1 need a constant volume signal fed into it and then a DSP with volume control be required after the APL1 to adjust volume?


It is very good if the digital signal source device has its own volume control. Everything will work very well. Another story is about digital source without volume control and having digital signal level squeezed to FS. You must reduce equalizer gain to deal with such high level and avoid clipping.



madcowintucson said:


> What I have been doing is cell phone aptx bluetooth to optical converter=cheap. Then optical into behringer. So I could swap out the behringer stuff for an apl1. Then on from there into optically into a dsp. My cell phone is what I listen to most on milk or slacker it sounds good enough for me.


It should work very well!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



madcowintucson said:


> What I have been doing is cell phone aptx bluetooth to optical converter=cheap. Then optical into behringer. So I could swap out the behringer stuff for an apl1. Then on from there into optically into a dsp. My cell phone is what I listen to most on milk or slacker it sounds good enough for me.


APTX protocol still has some limits regarding Hi-res music streaming. What you can use with Android phone is otg (on to go) USB cable directly to Behringer sound card with oprical out. It works perfect for me together with APL1. Now I can listen to FLAC music in the car.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What otg to optical converter are you using. I also was thinking hdmi to optical. Those boxes are cheap, since we don't need a dac I can get them at monopole for cheap. I just didn't want any wires to my phone the aptx sounds fantastic for streaming milk or slacker. So yeah I can stream milk and all them through hdmi to optical as well.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right now - Meridian Explorer:
http://www.amazon.com/Meridian-Explorer-USB-DAC/dp/B00BCJWTAM

But Behringer 202 worked olso fine for me (both usb-powered).
I do not have HDMI out in my cell phone, so I have no need to invest in video-part provided by the HDMI. 96/24 is ok for me.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oic, so the meridian is working as just an optical converter? I tried this using a topping USB to optical. It worked perfect on my laptop but I only got it to work one time on my phone. I was so frustrated. The idea was just a cheap phone otg to optical but why oh why only once did it work lol. So if you have a car pc or something that work great to go to optical. A better, albeit bulkier option, was hdmi to optical, totally stable from the android platform and cheaper, still getting full bandwidth out of that. 


I should know this, but does the apl1 have a switching input so I can go from optical to another format?? And if so how is the input selected?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

As soon the APL1 gets a digital signal, it will automatically swith to it. To choose between OPT and COAX digital you need to select one on the board inside the unit. Please ask the vendor about details. I have not used this function by myself. No need for COAX ... and APL1 was at the beginning programmed for optical digital input.

I have never got issues with Meridian and Behringer sound card. Both work perfectly with USB Audio Player PRO ... app. Hibymusic on the contrary gave some problems. I do not use it any more.

You must check if your phone is compatible with the otg-function. Mine Samsung Galaxy s4 is fully ready for this... Works every time.


----------



## madcowintucson

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

No I want to switch between analog and digital. I see it has both analog and digital in and out, I just don't see the way to switch. I want to go from hd radio to cd to android radio for example. So analog to optical and maybe coax if I choose. Is it all auto switching?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Regarding digital inputs of APL1.
Hello,
As soon as you power on your digital source the digital input of APL1 will be active.
The power down of digital source will activate analog inputs.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

A little update.

Been waiting to be a lot of measurements but I have had massive technical difficulties. Preamp broke on me (again), dropped my microphone in the floor, had to get a new one and on top of that the damn laptop crashed. Couldn't recover the data on the SSD drive and I had to redo every measurement again. Unfortunately lots of stuff got lost anyway...

These measurements are done with a bad preamp so there are some interference showing up primarily at 50Hz with some distortion overtones, rest of the the measurements are accurate enough though. Compare data above 200Hz.

I've gotten myself a new car since the last one had an automatic transmission breakdown, so new system and back to tuning again. Since the APL hardware is in my "main car build", I've been using the VST plugin and the workshop to do measurements and some experimentation with.

Here's a measurement of my new system after inital setup, basically only some crossover tune. No subwoofer installed in the car yet, working on that.



This was acquired with over 200 samples using the "APL method". The large peaks around 4-5kHz are a hassle, they are indeed audible. Don't know where they "come from" but it's not the speakers themselves causing this. 

Notice the resolution if we compare with a standard RTA 1/48oct smoothed with over 200 samples with "infinite averaging". Measured around the head as we normally do with this type of measurement.



As I've found out several times now, some parts of the measurements are correlating and others are not. I've tried multiple methods of acquiring the same results with traditional measuring methods but the results does never come near really, except below the modal range where a single point measurement usually is enough. The APL Workshop software does a much better job in finding problem areas with good resolution.

For this build I only have a Pioneer p99rs to tune with, which means a dual channel 31band GEQ. Even with this limitation I can attain a better center image when I use the workshop software to base my corrections from. Even when I initially tuned the center image with my 1/3oct spaced correlated noise files by ear, the measurements correlate better with what I hear in APL. Using averaged sinesweeps/RTA does correlate in lots of areas but never accurately throughout the whole spectrum as the APL software does. 

I will do a few experiments later on after I get my new preamp to show some further examples.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Looking good even without APL1 correction. This means - good components chosen and correct install done. Less work is left for Workshop and APL1. As it improves the overall situation with the small phase problems, the final result is expected to be quite predictable - very close to the selected target curve. The better "before" situation - the better will be a final result. This rule works also for APL as its capacity will be enough to struggle against non-perfection of the speakers, errors in mounting, reflections from the cabin surfaces, etc.

The Workshop along is a powerfull tool (maybe one of the most powerfull on the market today) for tuning, but applying of TDA will be further improvement on the way to SQ. The Workshop programme works only with one channel at a time and therefore the mutual cancelling and unnecessary dips are to be revealed and eliminated later (or at least minimized) by TA and phase alignment with the help of TDA software. In this case with a mic placed in the listening position opposite to the sweeping method of Workshop/APL.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Looking good even without APL1 correction. This means - good components chosen and correct install done. Less work is left for Workshop and APL1. As it improves the overall situation with the small phase problems, the final result is expected to be quite predictable - very close to the selected target curve. The better "before" situation - the better will be a final result. This rule works also for APL as its capacity will be enough to struggle against non-perfection of the speakers, errors in mounting, reflections from the cabin surfaces, etc.
> 
> The Workshop along is a powerfull tool (maybe one of the most powerfull on the market today) for tuning, but applying of TDA will be further improvement on the way to SQ. The Workshop programme works only with one channel at a time and therefore the mutual cancelling and unnecessary dips are to be revealed and eliminated later (or at least minimized) by TA and phase alignment with the help of TDA software. In this case with a mic placed in the listening position opposite to the sweeping method of Workshop/APL.


Yeah indeed. Would be fun to meet up some day and listen to eachothers systems. I do live quite close to the bridge


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'm pretty close on ordering a apl 

I have a few questions tho and hope someone can help. 


1. If I'm using a apl post dsp on 2ch will it be able to handle just correcting a pass band? Midrange only? 

2. How does it react to changes in signal after its corrections are done? 

Another words , with my p99 I like make TA/EQ adjustments as I'm driving. Will I still be able to do that without the apl radically changing its corrections or how it relieves its input signal? 

Thanks in advance ,


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> I'm pretty close on ordering a apl
> 
> I have a few questions tho and hope someone can help.
> 
> 
> 1. If I'm using a apl post dsp on 2ch will it be able to handle just correcting a pass band? Midrange only?
> 
> 2. How does it react to changes in signal after its corrections are done?
> 
> Another words , with my p99 I like make TA/EQ adjustments as I'm driving. Will I still be able to do that without the apl radically changing its corrections or how it relieves its input signal?
> 
> Thanks in advance ,


If you connect only midrange - yes. It will do. As far as I remember you could also change the working range, but was never interested in this as it is not clever not to use apl1 capability.
It is a stupid machine. You test and it corrects. If you make some changes by HU, a new set of measurement is necessary. Suggestion: first TA and XO and only after this make test to create a correction curve. Manual adds after are unlimited, but let apl to make job. 

Retest will depend on how severe are your current changes. Apl is not checking it in a real time. Remember to check target curves after some time if you install brand new speakers. For sure they will change their behavior.

I used to change only a low-end fraction while driving - sub volume from HU, as mastering quality is varying a lot. Actually it is nothing to do with mp3. 

For TA it is best to use TDA, if you have another opinion, you will change it quickly after just few tests.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

1. Why do you want to use it post DSP? If so then yes, it's 2ch.

2. No problems there. Got a p99 myself and fiddled with settings. It bases its settings on the input signal it was fed with during setup, then it's fixed there. I believe you can swap between 16 different setups using a switch iirc... 

Hope that answers it.


Skickat från min iPhone med Tapatalk


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> If you connect only midrange - yes. It will do. As far as I remember you could also change the working range, but was never interested in this as it is not clever not to use apl1 capability.
> It is a stupid machine. You test and it corrects. If you make some changes by HU, a new set of measurement is necessary. Suggestion: first TA and XO and only after this make test to create a correction curve. Manual adds after are unlimited, but let apl to make job.
> 
> Retest will depend on how severe are your current changes. Apl is not checking it in a real time. Remember to check target curves after some time if you install brand new speakers. For sure they will change their behavior.
> 
> I used to change only a low-end fraction while driving - sub volume from HU, as mastering quality is varying a lot. Actually it is nothing to do with mp3.
> 
> For TA it is best to use TDA, if you have another opinion, you will change it quickly after just few tests.



Okay . That makes sense. It sounds like a whole lot of work. 

Basicly my system sounds superb ....(not bragging it does sound excellent) EXCEPT FOR....(the depressing part) there's a reflection off the glass from my 7" dash midranges. The sound around 630hz is reflected and causes a nasty phase issue where it's out of phase at 630hz between left and right. 

That's really the only issue with the system. Other than that one problem it's fantastic! 

It sounds like the APL one will address my reflection problem and my phase issue , other than hooking it up, doing the correction, I want to be able to use the p99 as normal and make adjustments on the fly ( yes because recordings vary so much) that I love doing with this deck. 

Do you see any issues I could potentially have?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Correct, that was exactly my feeling about the present setup (at that time) before I purchased the APL1 and Workshop. It opened the freedom for further improvement. If you are as good as APL with its 4096 filters and can get the same results by using ears, than the APL will just save your time. No many people can compete with DSP having more than 31 bands  Correct me if I am wrong.

Along with APL1 I have a switch which I use for different target curves and volume control when a CD changer connected digitally to APL (from 0 till -18dB, five steps). Ai-net can only make this from HU if connected with RCA cables (analog).

Regarding reflections at certain frequencies - I made additional lab work to deminish their influence just by moving fronts accordingly. Most of reflections and cancelling dissipeared then. Such TA job does not influence the former corrections made by APL separately for left and right channels. What I could hear now is more details and some kind of surround sound comming from other directions than the speaker placement. Sure, improvement achieved by that is not drastic, the tonal balance is almost unchanged, but it is audible.

And actually it is proved to be true as a graphical presentation of RTA in time domain became more stable for the whole working range. I used software called TDA, version 10, for this purpose.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Yeah indeed. Would be fun to meet up some day and listen to eachothers systems. I do live quite close to the bridge


Good idea. Contact me (PM) when you intend to cross the bridge in the near future and we will find the solution. Despite the fact that parallel to my virtual life I have also a real one with some obligations (job, family, children, ...) Quite a busy Fellow


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Since I got new measurement gear and moved my computer to another place in my living room I figured I could re-measure my computer speakers.

The main speakers are widebanders in vented boxes, TangBand w3-871s.

Here's the left & right side measured in APL workshop.



I made a pink noise/RTA measurement with 250 samples with both speakers on (measured around sitting position). I extracted the difference with and without the APL VST on.



If you check the first plot and compare it to the second you'll see that the acoustic response correlates well with the corrections made.

Tried out a few different curves while I was at it. The curves affect tonality only, center focus and major staging elements remain the same whatever curve you choose.

- - - - - - - - - - - - - - - - - - - - - - - - - - -

"Flat" - Sounds very open/spacious, very neutral character. Nothing stands out. I like this...




"MP1" - Too bass heavy, midrange sounds recessed. Didn't like it.




"PD4" - Pretty neutral sounding, a little recessed midrange, less presence. Sounds more laid-back. Sounds ok.




"1dBperoct" - Kind of bass heavy, sounds open and spacious, similar to the flat setting. Sounds pretty neutral in otherwise... Sounds pretty good but the flat setting is better.

 


"ES1" - Sounds neutral. More presence in the "low vocals", more bass but not too much. The flat setting sounds more open than this but on some bad recorded tracks the ES1 sounds more balanced. 




I found it interesting because the curve I liked the least with my computer system is the one that sounds the best in my car (mp1). The flat setting got too little bass in car and the lower midrange sounds washed out, the mp1 setting fixes that. Again, this is nothing new - knew beforehand that the same target responses sounds different in cars and home environments.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hanatsu:

1st off thanks for all your advice ! 

I've been really trying to decide on the minishark or the apl1

I've been reading a lot of posts on diy that rephase author has posted (pos)
And rephase with the mini products sounds way over my head. 

The APL seems a bit more easy. However it seems over my head a bit as well.

Is this something I should even try? I'm not very smart when it comes to this level of ..... Stuff.

I really badly want to fix some phase issues tho. 
Whe I look at the phase responce in REW is goes from -180 to +90 back and forth and has like perfectly streight up and down transitions between some smoother Transitions all throughout 200hz to 1k and some smoother transitions after 1k.

The transitions look like a saw tooth to try to describe it.

Am I barking up the wrong tree? 

Right now I have my midbass on rev phase just because the transition to the midrange goes out of phase that bad. If I change slopes or crossover the way I like the sound goes away. 

I want to keep the settings I have but fix the phase problems. 
Is there anything easier? Or what is the easiest prouduct to do the job. Thank you, 

Cheers


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Minisharc and rephase requires manual tuning. You need to measure the FR, export it to rePhase, EQ the response, export it as a impulse response and then send it to the hardware unit. The way you need to measure (sine sweep in REW), you can only do accurate single point phase measurements. Single point measurements only have good accuracy in the lower frequencies. While you certainly can attain good results with it, it does require more work - more advanced if you will. 

APL measures power response and got an accuracy that you can't compare to single point measurements above the modal range. It also applies corrections automatically based on what curve you choose. APL isn't that advanced to learn, to use the basic functions you can go with the initial settings for the most part and it's pretty straightforward to work with. If you got correctable issues in the mag/ph response it will fix it for you.

If you looking at phase I'd recommend looking at group delay, it tells you about the minimal phase region that's correctable.


Sent from my iPhone 6 using Tapatalk.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The "sawtooth" will dissappear if you choose unwrapped phase view btw.


Sent from my iPhone 6 using Tapatalk.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> The "sawtooth" will dissappear if you choose unwrapped phase view btw.
> 
> 
> Sent from my iPhone 6 using Tapatalk.


Duh! I'm a idiot. I can't believe I've been using REW for this long and never seen that. Oh my gosh I feel dumb now. 

Well it looks better , not perfect tho. Still some wavy lines in midbass but mostly flat ish .

The wrapped version is a lot more in line of what I'm hearing tho. 

Like my midbass plays 60-500 and all through the pass band there's areas that sound correct and areas that don't. When I reverse the polarity in both midbasses it makes 300-500 hz sound way way way better and blend with the midrange a ton better, but than there's issues below 300 when I have normal polarity the 100-300 range sounds normal but 300-500 sounds very much out of phase . And dosent blend with dash mids at all. 

I look at the sawtooth graph and listening to the system it really makes sense on how it sounds. 

I think the dash mid/pods are playing a negative effect on the phase at crossover . 

When I reverse the phase on midbass it sounds better but imaging goes to hell.

I have tryed using time delay to ajust for the half wavelength at crossover and nil. 

This is why I think the APL will help me .

I have read a bunch and people say that phase isn't audible, maybe I'm hearing group delay? Or both. 

For me I want to dive into the APL and just learn it and make use of it . However I would feel very sad if it didn't fix my problem areas .

I also have that 630hz suck out as well that is a mess also.


If you think APL will help me , I will place my order tonight . 

What do you think ?


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Phase is such a common subject for headache so I will probably make a thread about it. Looking at at an unwrapped phase plot is pretty impractical. A time delay (T/A) would look like a downwards sloping line as it's linear vs frequency (1ms at 50Hz = 18deg but 1ms at 500Hz = 180deg). Group delay is a derative of the phase response, basically it's the negative slope of the phase response that will be displayed as a positive peak. So any downwards sloping part of phase response indicates a delay. In the "wrapped phase" plot it only goes to 180deg before it goes full circle and hits -180deg on the other side. The wrapped phase view is easier to derive something useful from but even that is tricky. 

Group delay tells you what you need to know, it tells you about non minimal phase regions. If you "generate minimum phase" in top right corner under the GD tab you will now see two new plots; "minimum group delay" and "excess group delay". Minimum group delay shows you the GD of a system perfect minimum phase chatacteristics, excess group delay shows the excess between a minimum phase system and your actual GD. This is done to highlight all areas which ain't minimum phase and therefore can't be EQed. This usually correlates to large dips in mag response. 

Know that this is valid for only one point in space, move the mic and you'll move all the peaks around in the EGD plot too, the higher in frequency the worse it gets.

APL doesn't measure one point in space, it does multiple (I tend to do at least 200+) in continious sweep bursts. This allows the unit to correct mag/phase over a larger region with retained accuracy. If the issues you got not due relective destructive interference the APL unit will fix it. 

One other thing about phase audibility. There are "different types of phase". First off absolute phase which is completely inaudible, this means you won't hear if both channels in a signal is shifted 360deg for example. Relative phase between L/R is very audible, in fact our mind uses phase differences in lower frequencies to localize sound direction (i.e staging mainly below ~1000Hz). The we got group delay (frequency dependant delay) which also is audible, the threshold varies vs frequency. You can read more about this in detail with a "group delay audibility" google search.

APL will improve upon any system. That is my experience after trying it in cars, home audio systems and even headphones.


Sent from my iPhone 6 using Tapatalk.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> If you think APL will help me , I will place my order tonight .
> 
> What do you think ?


You will not be dissapointed. 

Above to APL1 you might purchase the APL VST plugin, which works perfectly with Windows on my PC. I am using foobar2000 as a media player. Plugin is almost 3 times cheaper than the hardware version of APL. 

Actually applying APL concept demands some basic knowledge of what you are doing, some practical experience with calibration and measurement techniqs. But the results attained with the help of APL are worth trying.

To be honest (finally!), I have never seen a device, that is so successful in many different areas as APL: big concert halls, home cinemas, room stereo and finally - car audio with some first places at EMMA Eurofinals. You could read more about awards on the vendor's homepage. That actually has convinced me to buy APL, Workshop and TDA sofware and to leave the Army of enthusiasts having nightmare of system tuning. Three years run with APL in the two installs made me really happy with this unit.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> You will not be dissapointed.
> 
> Above to APL1 you might purchase the APL VST plugin, which works perfectly with Windows on my PC. I am using foobar2000 as a media player. Plugin is almost 3 times cheaper than the hardware version of APL.
> 
> Actually applying APL concept demands some basic knowledge of what you are doing, some practical experience with calibration and measurement techniqs. But the results attained with the help of APL are worth trying.
> 
> To be honest (finally!), I have never seen a device, that is so successful in many different areas as APL: big concert halls, home cinemas, room stereo and finally - car audio with some first places at EMMA Eurofinals. You could read more about awards on the vendor's homepage. That actually has convinced me to buy APL, Workshop and TDA sofware and to leave the Army of enthusiasts having nightmare of system tuning. Three years run with APL in the two installs made me really happy with this unit.



Okay . Im going for it . Im going put my order in when I get off work today. 
IM very excited to learn it

Thanks for taking the time guys . I can't wait to see the results


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> You will not be dissapointed.


Don't think anyone will...


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I still can't seem to wrap my head around the concept that a 2 channel EQ placed in front of the DSP can fix phase issues created by an IIR crossover.

I believe you guys that it works.... but man, I just keep trying to process the concept in my head and just feel baffled. 



I'm tempted to buy one of these things, or maybe a miniDSP OpenDRC unit, just to try it out. The only hangups I've got are source related:


1. I'm planning a new project car right now that will have multiple sources. Most likely 2 optical sources, plus 1 analog source. Switching sources could easily be handled by a Helix DSP Pro, but if I wanted an ALP1 in front of the Helix that would only work for 1 source unless I had some source switch upstream from the APL1.

2. The sample rate on the APL1 is only 48k. Since I will have digital sources with higher sample rates than that, plus a Helix Pro which processes at 96k, that's a bit of a downer to me that the APL would be downsampling to 48k before the signal even arrives at the Helix. Not the end of the world, but it's a bummer to be buying a hi-res source unit with high sample rate and then not take full advantage.



Putting multiple APL1 units after the Helix Pro would be a possible solution to the source issue, but I'm not sure if I'm that excited about it yet to go that far.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Crossovers must be fixed beforehand. It's a non mimimum phase issue.


Sent from my iPhone 6 using Tapatalk.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

APL1 has two digital inputs: Coax and optical, but as I am concern, they will not switch automatically between each other. Between analog and digital input - yes, works perfect.


BTW, there are many cheap switches on the market:

http://www.maplin.co.uk/p/3-way-optical-digital-audio-switcher-l34ak


----------



## Niick

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Speaking of acoustic phase, single point in space, and all that.........

One of the reasons that I have began using Smaart v7 (started using it again, it's the program I started with) is because of its real time phase and magnitude measurement capability, you can measure multiple SIMULTANEOUS transfer functions as well as have a real time average of the magnitude AND phase, ALL running simultaneously. 

So, for example, say you have a 5 or 6 mic array (running into a multi-channel interface), you can have on the screen the magnitude AND phase measurement of each mic position AND an averaged magnitude AND an AVERAGED PHASE! 

A lot of analysis (in fact, every other one I know of) systems DO NOT average phase data, because it isn't "real" I guess. But Smaart v7 does. So you can see the average phase response across those 4 or 5 (or whatever #) mics, in real time. 

It's pretty interesting. 

You can get a free 30 day trial. For anyone who is well versed with REW, it's probably very much worth doing, it's extremely enlightening to be able to measure in the frequency AND time domain in real time. 

This thread is a very interesting read, I thought I'd throw that out there for Hanatsu and others who might see a potential benefit to measuring multiple mics simultaneously and multiple phase measurements averaged together. 

Not at all trying to "hi-jack", my apologies to anyone who might take my post as such.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am sure APL TDA does not averaging phase data. Data are received from one point. The major idea of this test is to investigate possibilities of TA based on the real measurement with the mic placed in the listening position. Correct - to place in correctly is art.

REW in general benefits from spatial averaging when measuring the frequency responce curve. But I can not see how averaging of phase could have further potentials for TA alignment. In any case, the final touch will be done by ears.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I found it interesting because the curve I liked the least with my computer system is the one that sounds the best in my car (mp1). The flat setting got too little bass in car and the lower midrange sounds washed out, the mp1 setting fixes that. Again, this is nothing new - knew beforehand that the same target responses sounds different in cars and home environments.


Some time ago I have found the RTA curve developed by Bruel&Kjær for home stereo speakers. They called it "ideal curve". To my opinion, it is too bright in the car (especially in the mid range) and scene missed its deepness compared to mp1 target curve. But for home application it seems to be a good one. I have SNELL EIII loudspeakers as front for my home cinema with quite similar tendency to reproduce this "B&K Ideal curve".









One could try it...


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Niick said:


> Speaking of acoustic phase, single point in space, and all that.........
> 
> One of the reasons that I have began using Smaart v7 (started using it again, it's the program I started with) is because of its real time phase and magnitude measurement capability, you can measure multiple SIMULTANEOUS transfer functions as well as have a real time average of the magnitude AND phase, ALL running simultaneously.
> 
> So, for example, say you have a 5 or 6 mic array (running into a multi-channel interface), you can have on the screen the magnitude AND phase measurement of each mic position AND an averaged magnitude AND an AVERAGED PHASE!
> 
> A lot of analysis (in fact, every other one I know of) systems DO NOT average phase data, because it isn't "real" I guess. But Smaart v7 does. So you can see the average phase response across those 4 or 5 (or whatever #) mics, in real time.
> 
> It's pretty interesting.
> 
> You can get a free 30 day trial. For anyone who is well versed with REW, it's probably very much worth doing, it's extremely enlightening to be able to measure in the frequency AND time domain in real time.
> 
> This thread is a very interesting read, I thought I'd throw that out there for Hanatsu and others who might see a potential benefit to measuring multiple mics simultaneously and multiple phase measurements averaged together.
> 
> Not at all trying to "hi-jack", my apologies to anyone who might take my post as such.


I actually checked that program out last time you mentioned it. Haven't installed it yet but I'll be sure to check it out. I find it interesting to check out different audio software. Thanks for the tip btw.

REW can average phase measurements too, sort of. Not in realtime but if you choose multiple sweeps you can move around the mic between the automatic measurements and get an averaged reading. Don't know how this works or even if it's intended to work this way though. Smaart7 is quite expensive I must say, $895 (!) for a full installation. I only got two mics and maximum two inputs on my preamp but I can definitely see some experimental use for such a function.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I still can't seem to wrap my head around the concept that a 2 channel EQ placed in front of the DSP can fix phase issues created by an IIR crossover.
> 
> I believe you guys that it works.... but man, I just keep trying to process the concept in my head and just feel baffled.
> 
> 
> 
> I'm tempted to buy one of these things, or maybe a miniDSP OpenDRC unit, just to try it out. The only hangups I've got are source related:
> 
> 
> 1. I'm planning a new project car right now that will have multiple sources. Most likely 2 optical sources, plus 1 analog source. Switching sources could easily be handled by a Helix DSP Pro, but if I wanted an ALP1 in front of the Helix that would only work for 1 source unless I had some source switch upstream from the APL1.
> 
> 2. The sample rate on the APL1 is only 48k. Since I will have digital sources with higher sample rates than that, plus a Helix Pro which processes at 96k, that's a bit of a downer to me that the APL would be downsampling to 48k before the signal even arrives at the Helix. Not the end of the world, but it's a bummer to be buying a hi-res source unit with high sample rate and then not take full advantage.
> 
> 
> 
> Putting multiple APL1 units after the Helix Pro would be a possible solution to the source issue, but I'm not sure if I'm that excited about it yet to go that far.


Here's what APL does to the phase of a sealed subwoofer in a car. First measurement is an acoustic, the rest are electrical measurements with the output filters from first the MiniDSP and then the APL filters applied to the first measurement to see how it affects the output.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Some time ago I have found the RTA curve developed by Bruel&Kjær for home stereo speakers. They called it "ideal curve". To my opinion, it is too bright in the car (especially in the mid range) and scene missed its deepness compared to mp1 target curve. But for home application it seems to be a good one. I have SNELL EIII loudspeakers as front for my home cinema with quite similar tendency to reproduce this "B&K Ideal curve".
> 
> View attachment 122802
> 
> 
> One could try it...


Yeah, car curves and home audio tend to differ quite a bit.

I'm building new speakers right now, dipole widebanders with a ported subwoofer. I wonder if I can launch multiple instances of the APL VST and use it to optimize the entire cutoff range of the crossover, i.e use it in "2-way" mode.


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Would one of you gents please give me a _*minimum phase system vs non-minimum phase system For Dummies*_ explanation? I have tried to read about it but no luck with understanding it.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



brumledb said:


> Would one of you gents please give me a _*minimum phase system vs non-minimum phase system For Dummies*_ explanation? I have tried to read about it but no luck with understanding it.


There are minimum phase and there are linear phase systems. Using minimum phase corrections are the most common way to do it as we need phase shift to correct for the phase distortion of the environment when dealing with room acoustics. A perfect audio system in a perfect room without reflections is normally minimum phase (+delay). The phase response in a true minimum phase system will relate to the amplitude (magnitude) of the signal perfectly, if a system would be 100% MP then you could calculate the magnitude response from the phase response and vice versa. 

IIR filters in the digital domain emulates analog filters and are by definition minimum phase. FIR can be minimum phase or non-minimum phase, linear phase filters can be done with fir processing. This way you can have any phase response with any amplitude response, this is non-minimum phase.

Sound that is delayed acoustically and reflected off surfaces will have a different amplitude and phase response and will interfere with the direct sound at some point, this cause non-minimum phase regions to occur that cannot be EQed out fully. Any region where the amplitude and phase response don't correlate with eachother are not minimum phase, EQing these areas will yield unpredictable results. 

RoomEQ for example can calculate how the minimum phase response would look like in a perfect system and compare it with the actual phase and from there give you the "excess phase".


----------



## Niick

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> . But I can not see how averaging of phase could have further potentials for TA alignment. In any case, the final touch will be done by ears.


maybe you cannot see this because you have not done it? When I say spatial average, I'm talking about the mics being in a rather tight formation about the listener's head area.


----------



## Niick

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oh, yeah, I remember now why I came back to this thread....I was searching thru threads on a another forum and found this delay estimation and measurement

Rather interesting, it's the inventor of APL talking about the time delay analysis software he wrote. 

I wasn't sure if anyone had already posted a link to this thread or not. If so, oops.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Niick said:


> maybe you cannot see this because you have not done it? When I say spatial average, I'm talking about the mics being in a rather tight formation about the listener's head area.


That was I also ment - spatial average around the head at the listening position. EQ-wotk in this case can be optimised due to averaging of reflections. In the case of TA (Group delay, phase issues) I used to apply graphical presentation for the whole frequency range, which APL TDA sofware provides me after just one sweep. It is not a real time. You could correct time alignment based on RTA, DFR and other graphs. Afterwords - there is a possibility for further improvement - when sending sweep simultaniously to both front channels. it is very easy to see how these channels interfere each other. By the way - trial version is free, as I remember.

Yes, Raimonds Skuruls came to caraudio from the prosound world. and his APL (from 2009) is a mini-version of Coneq unit used for big concert halls, etc.

For your information this concept is used today by some producers of Tv's. PanasonicTX-PR50GT30 is one of them.


----------



## Niick

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> That was I also ment - spatial average around the head at the listening position. EQ-wotk in this case can be optimised due to averaging of reflections. In the case of TA (Group delay, phase issues) I used to apply graphical presentation for the whole frequency range, which APL TDA sofware provides me after just one sweep. It is not a real time. You could correct time alignment based on RTA, DFR and other graphs. Afterwords - there is a possibility for further improvement - when sending sweep simultaniously to both front channels. it is very easy to see how these channels interfere each other. By the way - trial version is free, as I remember.
> 
> Yes, Raimonds Skuruls came to caraudio from the prosound world. and his APL (from 2009) is a mini-version of Coneq unit used for big concert halls, etc.
> 
> For your information this concept is used today by some producers of Tv's. PanasonicTX-PR50GT30 is one of them.


 I often overlook the very different perspectives that I and the majority of DIYmobileaudio forum members have. Especially regarding tuning and car audio in general. I am always looking at it from a perspective of multiple cars, multiple scenarios, many unknowns regarding these cars and their installations, often times the design and installation of the systems I'm working on was not done by me. Or anyone I know. And time is a massive factor. 

It's in the HF where I see the POTENTIAL benefit of multi-mic averaging phase responses. Smaart v7 is able to resolve phase in cars without the usual mess of noise and random lines most other measurement platforms have. Again, with unlimited time on your hands, you can achieve this with REW too. The rather new frequency dependent windowing feature of REW works a treat for resolving phase data in the HF in cars. I've tried it. 

I want to download and test out the TDA software when I have a little time to experiment with it. It looks interesting. And as far as FIR filtering, that's on the agenda too. Although, the smallish amount of taps being used by APL makes me wonder about its effectiveness AS COMPARED TO OTHER FIR systems I've read about. 

Of course, this is just a thought, I'm sure it works great, no doubt about that. But with other systems (although none of these other systems are at present made for car audio) using many, many times more taps than APL, and with manufacturers like Audison soon to be entering the market with FIR technology, I'll bet ya it isn't long before the APL1 is in need of a refresh, a version 2 if you will, in order to stay relevant.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nick, fully agree about necessity of upgrade of the APL unit in the near future. Me too - missing some smart features (like Bluetooth, tuneIt, multiple digital input, etc.). The major concern is actually about a limited possibility for time alignment. You simply have to use another post-DSP for this purpose (as I do). But on the other hand - final adjustment of TA (0-5 msec) could be made much-much more accurate compared to other DSP's like H800, as an example. So, the best way to use APL1 is to combine its strengths with further processing by another DSP. MiniDSP can be a good choice. Then you can go full active. 

There is another version of APL (for home application) available on the market - with 96kHz internal processing, but I will doubt if majority of customers could hear a difference between 48kHz processing (with downsampling) and 96kHz (without). Especially during driving. If you tune a car for competition - it might be another story indeed.

On the other hand - APL1 should be compared with existing car designed DSP's with FIR filters. But not with professional equipment from other branches, from different price levels. It's my point, you might disagree, of course. If one will compare the APL1 with 4096 FIR filters with normally used 31 bands/channel, so APL will be definetely a winner. The difference is audible, and this is the most important here: sound quality and capability of the device to rich the goal.

My personal experience with the APL1 - 3 years continuos run without issues. Funny to mention, I've started to drive little bit slower in order to prolong the pleasure of listening


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Even if other manufacturers make fir based processors more widely available it doesn't really matter, I mean the MiniDSP DIRAC and the MiniSHARC is already on the market. You can use these units with rePhase to EQ your systems but you need accurate measurements to acquire the data for accurate corrections. The power of APL lies in its software and how it attain acoustic data imo. No matter how powerful hardware you got, it can't do any good unless it knows what to correct for.

Regarding sample rates etc... 48k vs 96k doesn't have any real benefits in reproducing audio. 48kHz sampling gives us the Nyquist frequency of 24kHz which is beyond human hearing. This 24bit craze is also ridiculous, it only affects the dynamic range. The DR of the normal 16bit system is far from capped with any recording available. Vinyl recordings got about 11bits equivalent DR if you find material with a good master. I'd even be so bold to say that there are zero audible difference between 48k/16 and 96k/24. 

I still stand by my claim that there are no real audible difference with mp3 with a bitrate above 256kbit/s against any lossless format. Our hearing ain't sensitive enough to discern certain forms of distortion and loss of data that get masked by overlapping frequencies, there are exceptions of course - people who know exactly what to listen for with certain material as proven by that klippel ABX distortion test.

Deviations in the frequency response that cause staging issues due to phase inconsistencies between left/right channels are by far the most audible forms of distortion. APL does a wonderful job compensating for these issues.

Sure, I'd like to see some other features like BT control, wireless streaming, tablet compatibility etc and most of all a complete all-in-one solution DSP/amp. In a future APL v2 I'd like to see a complete DSP:

*10 output channels, 6 analogue inputs (2 with input sense) and 2 toslink inputs
*Crossovers 6-48dB/oct on each channel + HS/LS filters.
*Gain control with 0,1dB accuracy on each channel with the capability of locking left/right side channels together.
*Low-increment T/A with 25ms range on all channels.
*Volume dependent EQ
*Direct USB or WiFi stream from harddrive or Apple/Android unit with FLAC, mp3, wma, ALAC decoding. Control via iPod/iPhone/iPad/Android (wifi or BT)

AMP, Class D fullrange.

4x25/50Wrms @ 4/2ohms
4x100Wrms/200Wrms @ 4/2ohms
2x300Wrms/600Wrms @ 4/2ohms bridgeable for 600W @ 4ohm.

APL EQ on each speaker. Correcting the entire stopband of each driver. All-in-one software solution with the ability of manual control of allpass filters (phase EQ) on all channels. Realtime updating the graph while measuring would be cool too. Integrate TDA pl graph to show before/after corrections. 

If such a unit could be made, it would destroy the competition completely. A box of awesomeness xD


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right. It is nice to dream. but the reality create some limitations. And it is not a bad idea to accept those, which have logical background. I do believe that based on psychoacoustics the APL company have designed the full concept of measurements and tuning, which is enough for caraudio for the best perception of sound.

Some people are talking only of the APL1 unit camparing it with other DSP's. But actually the software provided by APL company is not less interesting. Especially for those who are trying to heal the sound in cars suffering from fault install, uncorrect tuning, etc. To my mind they could benefit from using this software and save a lot of time, increasing incomes and efficiency of their work. Am I so wrong?

Working at the accredited lab, I spend a lot of time everyday on calibration of measurement equipment, testing accuracy and repeatibility. Caraudio for me is just a hobby appart from some other forum members. But I will just express my overall satisfaction with the APL concept as a whole, including the APL plugin for carPC and home computers. It works perfect even without this hardware box called APL1.


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have very limited understanding of the hows and whys of the APL1. It seems that it is best in the hands of very experienced audio guys. (which is not me) So this may be a dumb question, but. 
Is there any reason not to use APL1 with a MS-8?  Auto tune with the JBL MS-8 then auto tune further with the APL1.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



1fishman said:


> I have very limited understanding of the hows and whys of the APL1. It seems that it is best in the hands of very experienced audio guys. (which is not me) So this may be a dumb question, but.
> Is there any reason not to use APL1 with a MS-8?  Auto tune with the JBL MS-8 then auto tune further with the APL1.


I will recommend to use APL for EQ and MS-8 for TA. APL1 has only two channels, so it is not possible to use it alone for active install. The APL1 has 4096 minimum phase FIR taps, so why to destroy everything afterwords with another processor? Actually it is not too much complicated to use APL with its measuring technique. Once you learned it - everything will be fast, logical and easy. The most important - repeatibility of results (acoustic power frequence response) - it is simply amazing. Then, do not forget that APL's software permits unlimited correction of the results obtained from the measurements. A switch with 16 positions will give you possibility to change quickly from one target curve to another. I use it also as a volume control when the CD changer connected digitally to the APL1.


----------



## Niick

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I will say that I think it's wonderful actually that such a product exists for car audio as the APL1. On a regular basis I'm completely baffled by the proliferation of simplistic 31 band graphics STILL hanging around, and even being released as new products. 

This is baffling to me. But such is the nature of mainstream car audio. I've said it before, but the continued staying power of the lowly 2 conductor RCA connector as the "industry norm/standard" speaks volumes about the mentality of the mainstream car audio industry as a whole. 

This is only my opinion. I'm sure that it's not difficult for someone to make an argument against any of these points. 

So, in closing, I say, the more people who buy, use, promote, and cause others to buy, use and promote products like the APL1 the better. These are the type of products from out of the box thinkers that this industry so badly needs.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'd be curious too about a combo with ms8, since I already played a bit with dual dsp (to keep L7 and easy auto tune for 8+ channels).
We know the ms8 cannot do TA without EQ/phase, they're all tied together, only thing still working when its DSP is off are the crossover settings.
So if ms8 is the master (for logic7 for exemple) > only two channels so bye bye the XO
If it is the slave (to manage a front 3 way) > XO ok, TA ok, but double EQ/phase

In my experience ms8 impacts a lot the phases, more than EQ.
I tried dual ms8, and both seemed to work in the same directions.
Well, based on what I could read of my before/after REW measurements on each.
And it sounded nice and fun so maybe it can work!
(I'm not a golden or even silver ear like you guys)


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Doesn't matter what the ms8 does to EQ/phase. APL will measure the acoustic response and correct based on that. It doesn't "know" that the ms8 modifies the signal.

I agree with Niick. I find it unbelievable that TOSLINK is considered "high end" in car audio. A $50 dvd player connected to your tv had toslink 15 years ago. Unbalanced analog rca should be phased out.


Sent from my iPhone 6 using Tapatalk.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ya, it is a question of music files formats as well.

Nobody expected us to listen to FLAC or even hi-rez music files. Mp3's from USB-stick is normal today, such a pitty. Digital out/in from HU is just a dream except some few models.

Think of Tesla - with its computerised features ... and how little has been done for SQ in this amazing car.

Sellers promote new cars with 12 or even 16 speakers as a selling parameter! More - better ... 

Average representant of a young generation does not know about sound processor and why it should/could be used in a car. Majority think simply that in order to improve sound quality - one should buy a subwoofer. Such a development!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Doesn't matter what the ms8 does to EQ/phase. APL will measure the acoustic response and correct based on that. It doesn't "know" that the ms8 modifies the signal.


I just expected that too much treatment could degrade the signal, or create some kind of conflict if both algorithms "fight" each other.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Ya, it is a question of music files formats as well.
> 
> Nobody expected us to listen to FLAC or even hi-rez music files. Mp3's from USB-stick is normal today, such a pitty. Digital out/in from HU is just a dream except some few models.
> 
> Think of Tesla - with its computerised features ... and how little has been done for SQ in this amazing car.
> 
> Sellers promote new cars with 12 or even 16 speakers as a selling parameter! More - better ...
> 
> Average representant of a young generation does not know about sound processor and why it should/could be used in a car. Majority think simply that in order to improve sound quality - one should buy a subwoofer. Such a development!


Most people I do car audio installs for don't understand why any form of processing is important, or don't even understand what EQ is etc. They don't want to pay the added cost of a DSP until I let them hear the difference themselves with T/A - EQ bypassed/on. Then suddenly most people feel like they need the processing. After a few months they say; "normal cars sound like crap now when I know how it should sound".

The questions I get the most when I say I compete in car audio is:

1. How many dBs?

2. How many speakers do you got?

3. How much did all of this cost?

The general car audio interest is usually just large subwoofers and deebeez. Demo a SQ car just isn't fun when you have to explain what they should listen for instead of maxed out bass... lol


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I just expected that too much treatment could degrade the signal, or create some kind of conflict if both algorithms "fight" each other.


Nah, don't overthink what happens in the electrical domain. What's interesting is how the acoustic magnitude response looks, how the acoustic phase response looks etc.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

ok 

Damn', another dsp on my list!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was waiting for the new ddrc88, but in the mean time I couldn't just ignore all your good words on this unit Hanatsu. So I pulled the trigger!


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I was waiting for the new ddrc88, but in the mean time I couldn't just ignore all your good words on this unit Hanatsu. So I pulled the trigger!


Be sure to let us know how it works for you. I am very interested to know how easy you find it to manipulate.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I was waiting for the new ddrc88, but in the mean time I couldn't just ignore all your good words on this unit Hanatsu. So I pulled the trigger!



Nice... I'm waiting for my 2nd unit myself. Post your results later 


Sent from my iPhone 6 using Tapatalk.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds measured my headphones (AKG Q701) and supplied me the EQ correction for them.





Look at the FR! One might think that a pair of good headphones would have flatter response than this.

Amazing to listen to them with and without the VST active to compare. I guess this could be called "reference sound". Once again, awesome...


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Funny pictures. Mine Sen HD457 have some similar problems in the range 0,7-5kHz, which I 've corrected with the VST plugin MathaudioHeadphoneEQ (including crossfeed). But honestlly speaking, I prefer JB Isone pro with HRTF adjustment and room acoustics. Do not think it worth sending them to Raimonds. Missing my previous Beyerdynamic a lot.


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## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How many taps do you guys generally need to use per channel?


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## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Look at the FR! One might think that a pair of good headphones would have flatter response than this.


Yep, looks a lot like this, inverted!


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Headphones needs to be measured through a set of artificial ears so the ELC curve is indeed a correct observation...


Sent from my iPhone 6 using Tapatalk.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just received mine! Will make a thread once I start.
I took few really rough measurements to get an idea of the process, it's promising!
I love the "one button" approach.
Well there's still the burden of the pc and a learning curve, but I don't see any big trouble, just need time to read everything and test.
In fact I see it almost as an advanced ms8, with customizable target, per channel, so big difference.
I already have few questions, but just one for now: does the unit need to be powered to sync with the pc, or is it powered by usb? I think I have trouble with the drivers...


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have one on order.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



brumledb said:


> I have one on order.


Cool! Looks like the begining of a little community around this
It seems so flexible, I'm sure we could learn a lot.


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## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am pretty excited. I am redoing a bunch of my install, so I am thinking at first I won't use the APL1. I will have it installed but either bypass it or Raimonds suggested I could also use a "flat" eq curve in the APL1 and that would be like bypassing it. I am thinking at first to tune with just my Helix like normal and see how it sounds and take measurements. Then go ahead and fire up the APL1.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sounds like you'll get the best of it, what do you plan as source?
Me till I find the next car I'll simply install it with in front of my ms8.
Just time to fiddle with both etc.


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am curious to see how it performs with the MS8.

I have a 2014 vehicle with a lot of built in features so I have a stock H/U. But it's going to go like this--from OEM Amp---JL Fix82---APL1----Helix---- (3)Mosconis. Right now I use an Ipod that connects to my truck via USB and not 3.5. Eventually, I would like to get a Fiio lossless player. Then I would just run digital straight from the Fiio to the APL1 and use the RCA connections for the Fix82 to APL1. That way, the headunit would be the primary and any time I want the Fiio I just simply turn it on. Whatever source is connected via the Toslink becomes primary when that source is turned on. And so just turn the Fiio back off and I would have my headunit back.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



brumledb said:


> I am curious to see how it performs with the MS8.


Me too, see if it can fix what ms8 didn't.
And I really want to keep it, or them since I might use two later.
I could use something else with surround, but I really appreciate the time it saves (and so far it does a better job than me).



brumledb said:


> I have a 2014 vehicle with a lot of built in features so I have a stock H/U. But it's going to go like this--from OEM Amp---JL Fix82---APL1----Helix---- (3)Mosconis. Right now I use an Ipod that connects to my truck via USB and not 3.5. Eventually, I would like to get a Fiio lossless player. Then I would just run digital straight from the Fiio to the APL1 and use the RCA connections for the Fix82 to APL1. That way, the headunit would be the primary and any time I want the Fiio I just simply turn it on. Whatever source is connected via the Toslink becomes primary when that source is turned on. And so just turn the Fiio back off and I would have my headunit back.


Sweet, and a lot of processing power. I didn't know the Fix82, seems a nice unit.
Good to know about the toslink, as I plan to keep my iphone in dash for now, and probably an ipad in next one. So I could replace my actual istreamer.
The easy switch between sources is another good value.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> does the unit need to be powered to sync with the pc, or is it powered by usb? I think I have trouble with the drivers...


Anyone can help on this?
I didn't really use windows since 10 yrs at least, completely rusty on this.
(I use Windows 7 on // desktop, and my mac too does not see the unit)


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

No idea if it powers up with usb. I can try in a few min...


Sent from my iPhone 6 using Tapatalk.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok. Mine does not power up on usb.


Sent from my iPhone 6 using Tapatalk.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Ok. Mine does not power up on usb.
> 
> 
> Sent from my iPhone 6 using Tapatalk.


Nice, thank you Hanatsu!


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is there one that has analog in and digital out?

Post back when you guys get them in with the MS8.


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## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It has digital in/out (both spdif and toslink) & analog in/out. 

And if I quote Raymond here:
"All outputs are working simultaneously all the time. You may use any of them.
But inputs - if digital signal is fed to digital input, the unit is switching from analog input to digital. If no digital signal - analog input is active.
The jumper switch is for selection between coaxial SPDIF and optical TOSLINK digital inputs."


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## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Products like this one are so intimating. I wonder why the manufacturers don't make a step by step set-up videos for these things. If they had a video, I probable would have bought one by now. (if it were in English)


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## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am also a bit confused as to what software does what, and which would you need to do EQ and the TDA stuff. And what is the difference in the functionality of the different licenses?


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



thehatedguy said:


> I am also a bit confused as to what software does what, and which would you need to do EQ and the TDA stuff. And what is the difference in the functionality of the different licenses?


This is the response from Raimonds when I asked pretty much the same thing.



> 1. You need APL Workshop to make measurement and create equalizer files for APL1 unit.
> I am recommending to use APL TDA software for initial setup. You may find APL TDA demo version sufficient for that.
> 
> 2. Yes, APL TDA is measurement software with focus on timing. The AFR (amplitude frequency response) curve of TDA process has some value also.
> TDA EQ is measuring AFR in more detailed way than TDA software but is using TDA process for that. The result is corrected (flat or target) AFR.
> 
> 3. TDA EQ is strong for near field applications with minor reflections. The car environment is not so in most cases.
> Workshop is giving very reliable results for a car environment.
> 
> TDA EQ software is showing all curves as TDA software except it does not show Non Linear Distortion Analysis.


So, Workshop is the software we need for use with APL1 that will generate the .fir filters. 

TDA is an analysis tool for time delay. For our purposes, the free trial will most likely suffice.

TDA EQ is a whole different animal that is designed for correcting near field measuring, like those found in studio monitoring.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



thehatedguy said:


> I am also a bit confused as to what software does what, and which would you need to do EQ and the TDA stuff. And what is the difference in the functionality of the different licenses?


Don't think there's any difference in functionality, it's more the purpose of usage. TDA is a measurement software. TDA EQ is a measurement software and correction fir generator designed primarily for studio monitor and nearfield corrections. 

APL Workshop is the primary measurement and fir creator software that measures and creates power response corrections which is sent to the APL hardware.

I might do a video review in a few days, I just hate to speak English as it's not my native language :<


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I see.

Was getting confused again looking over the site.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do a video review in a few days, I just hate to speak English as it's not my native language :<


A video could be cool for sure, with youtube translation if you prefer?
(btw you're not the only one with an accent )

But what you do usually with screenshots etc is already awesome!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Well in fact you know what, I'd be really curious to see how you "paint" during the measurements. A video w/ or w/o sound would be perfect


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Maybe this will help a little to understand how it works:

TDA – Time Domain Analysis software

and video, which I have found on the Russian TDA forum:

https://www.facebook.com/100001906122992/videos/o.942640939161471/1013353445404850/?type=2&theater


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Haha now I understand the look of my neighbor when she saw me last morning when she took out her trash 

He seems to do it a bit fast no?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Danley Sound Labs Inc. decided to use APL processing to relieve all beauty and nuances of their loudspeaker’s designs for a show at Prolight & Sound Frankfurt Musikmesse 2016. Come hear that in hall 3.1 (stand J81) and Concert Sound Arena.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Congratulations Raymond!
Will you be there?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Congratulations Raymond!
> Will you be there?


No this time, sorry : )


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nobody can regreet using the APL technology. It is not so easy, but the results worth trying.

Congratulations anyway, Raimonds.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Congrats Raimonds, I'm sure they will be happy with the results.


Sent from my iPhone 6 using Tapatalk.


----------



## cvjoint

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Bookmarked for more reading. Fascinating tech.


----------



## cvjoint

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Raimonds measured my headphones (AKG Q701) and supplied me the EQ correction for them.
> 
> 
> 
> 
> 
> Look at the FR! One might think that a pair of good headphones would have flatter response than this.
> 
> Amazing to listen to them with and without the VST active to compare. I guess this could be called "reference sound". Once again, awesome...












Etymotic target FR.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Heh the FR of the headphones are typical, because of the way they are measured in an artificial ear canal. What is "Etymotic" btw?


----------



## cvjoint

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Etymotic Research | How We Measure Response Accuracy

As they should be! They make my favorite pair of reference in-ear headphones.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



cvjoint said:


> Etymotic Research | How We Measure Response Accuracy
> 
> As they should be! They make my favorite pair of reference in-ear headphones.


Ah I see, something like this then?



Does sound a little more open in the upper midrange, but ~10dB is way too much. Got pretty harsh sounding at that point. The beauty of the APL workshop is that I can create any curve I want with the correction automatically applied


----------



## cvjoint

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Ah I see, something like this then?
> 
> 
> 
> Does sound a little more open in the upper midrange, but ~10dB is way too much. Got pretty harsh sounding at that point. The beauty of the APL workshop is that I can create any curve I want with the correction automatically applied


Yep! They claim to have a tuned chamber design that creates that target FR to "build in" what your ear shape would normally create. I don't know if other companies attempt to do the same, or whether they are as successful, but that should be imo the way the target FR should look. I just wish they designed them around my big ole ears.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



cvjoint said:


> Yep! They claim to have a tuned chamber design that creates that target FR to "build in" what your ear shape would normally create. I don't know if other companies attempt to do the same, or whether they are as successful, but that should be imo the way the target FR should look. I just wish they designed them around my big ole ears.


Ah cool. I knew about the headphones testing conditions but I've never really read up about how reference headphones should behave. Good to know!

Sounds really good now actually lol...


----------



## cvjoint

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Ah cool. I knew about the headphones testing conditions but I've never really read up about how reference headphones should behave. Good to know!
> 
> Sounds really good now actually lol...


Yeah, just make sure you apply that target FR to the same type of headphones (in-ear). Once you get hooked on it it's hard to listen to other tunes. 

You basically achieved their design with DSP instead of their tuned chamber and at the same time maybe fixed some other irregularities in the basic response of the headphones. Not to mention DSP hugs that target FR more precisely.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hanatsu do you listen from your pc then?
Would be another good reason to apply the correction on the source here, if played from a portable thing.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

VST plugin, foobar2000. It got no real limitations so if you want you could go crazy with the amount of taps used. If you use JRiver you could do virtual loopback and running measurement sweeps with APL or any convolution engine active to observe results (thanks Wesayso for that tip)...


Sent from my iPhone 6 using Tapatalk.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I just hate to speak English as it's not my native language :<


That never stopped this guy..... :laugh:


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Maybe this will help a little to understand how it works:
> 
> TDA – Time Domain Analysis software
> 
> and video, which I have found on the Russian TDA forum:
> 
> https://www.facebook.com/100001906122992/videos/o.942640939161471/1013353445404850/?type=2&theater




I still don't quite get it....



So do we use TDA to set the time delay in our normal DSP, and then use APL Workshop to generate EQ filters that will fix the response?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Generally speaking - yes. But I made Apl EQ first for the both front channels separatelly.

Actually the APL1 is provided by the software, that it able to make some small delays. I use the external DSP for this, as it can be controlled directly from the HU.
Sendt fra min GT-I9505 med Tapatalk


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Apl will correct the FR and thus the phase response. Pure time delays you need to dial in anyway, theoretically the apl1 supports linear phase so it could correct time delays as well. Right now it does minimum phase correction (which should zero all delay if T/A is set correctly and the response regions actually are MinPh).


Sent from my iPhone 6 using Tapatalk.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I've read this thread, and the TDA thread a few times over the last few months, and I decided today that it's time to get an APL-1...


----------



## crazhorse

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Good to see more people getting these .... more info to be had from others


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Great one more!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The order has been placed!

I only have 10 days off(not in a row) between now and the end of July, so let's hope I'll have the time to play with it before then.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I must admit, I am still horribly confused. 


Some questions....


1. Since this EQ creates filters for left and right channels, does this mean we need to mute all speakers on 1 side of the car and measure. Then mute the other side and measure?

Or do we measure with everything playing together?



2. I see that it is suggested to set only crossovers and time alignment on the traditional DSP, and leave the EQ to the APL1. However, setting a crossover on a DSP without using EQ is pretty much impossible. Electrical crossover filters will never have the expected acoustic result without EQ. For example, if you want a Linkwitz 24 dB slope @ 500 Hz, you will never be setting the electrical filter at 24 dB / 500Hz unless you use EQ to correct the response. So how do you know what you are doing with the crossovers in this case?

Furthermore, if you don't use independent EQ on a single driver to correct response then your crossover slope will probably be all over the place. It could start at a 24 dB slope but then drop off to a 36 or 48 just based on the natural rolloff of the speaker. So I am having a hard time understanding how a 2 channel EQ can correct response in the crossover region if it's not able to apply filters to the independent drivers. In other words, let's say your crossover region is 500Hz. The left side midrange speaker needs -3dB of correction at 520 Hz. But the left side midbass needs +2 dB at the same frequency. How is this conflict resolved without independent EQ?


----------



## crazhorse

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

You do mute and measure left and right separate, you end up with a left and right filter to apply.The apl1 goes after the hu and before the dsp if that helps any...


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

subterFUSE,

this is also what i have done
APL only doing LR equ, not independent driver
if I have different response in the crossover region between LR, I do the equ independent for each driver only to equ the diff

and also in apl workshop, there is the capability to play the impulse only left or right channel only




subterFUSE said:


> I must admit, I am still horribly confused.
> 
> 
> Some questions....
> 
> 
> 1. Since this EQ creates filters for left and right channels, does this mean we need to mute all speakers on 1 side of the car and measure. Then mute the other side and measure?
> 
> Or do we measure with everything playing together?
> 
> 
> 
> 2. I see that it is suggested to set only crossovers and time alignment on the traditional DSP, and leave the EQ to the APL1. However, setting a crossover on a DSP without using EQ is pretty much impossible. Electrical crossover filters will never have the expected acoustic result without EQ. For example, if you want a Linkwitz 24 dB slope @ 500 Hz, you will never be setting the electrical filter at 24 dB / 500Hz unless you use EQ to correct the response. So how do you know what you are doing with the crossovers in this case?
> 
> Furthermore, if you don't use independent EQ on a single driver to correct response then your crossover slope will probably be all over the place. It could start at a 24 dB slope but then drop off to a 36 or 48 just based on the natural rolloff of the speaker. So I am having a hard time understanding how a 2 channel EQ can correct response in the crossover region if it's not able to apply filters to the independent drivers. In other words, let's say your crossover region is 500Hz. The left side midrange speaker needs -3dB of correction at 520 Hz. But the left side midbass needs +2 dB at the same frequency. How is this conflict resolved without independent EQ?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It is not necessary to mute the opposite side, as in the APL Workshop during the tests one should select wether left front will be measured or right.

I do understand the concern about crossover points settings. APL will not change the electrical filter, while the acoustic point might move on after EQ. This is a task of APL to correct both sides to the same target curve. And this works amazing, even some people do not understand why and how. I really do not understand how my mobile phone works (in all the technical details), but I just use it. 

After EQ there is unlimited number of after-EQ corrections that could be made in a very advanced PEQ. If the box is connected to the laptop by USB cable it is even possible to upload these corrections to the desired preset individually for right and left channels. 

With APL-3 comprising six channels it is possible also to EQ separate drives, but why to make own life so complicated as the APL method can make its optimization work perfectly for the whole side despite previously done XO settings. One should give his drivers some head in order to avoid burning of the tweeters and avoiding the regions close to max on the impedance curve.

XO pre-work is a technical science, while application of the APL method is just a fun. And in order to make this fun optimal one should not forget about TA. It will create better circumstances for the APL to make its job, including solving of the minimum phase problems.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Skimmed through the thread. Got all drooling and excited about this box, especially hearing good words about it from Hanatsu.

So i am currently an MS-8 user. I have 3 way active front, 2 way central channel with a 6" midbass, rears and a sub. I just love the Logic 7 and don't wanna lose it. 

But... i wanna try these two devices in a tandem.

The thing is, in my 2007 Cayenne i get the sound signal from MOST optics which is converted by moBridge into TOSLINK, fed to a cheap DAC and then RCA'ed to MS-8. 

Since APL1 has both digital and analog IOs, I would love to see the following signal path with APL1:

HU --MOST--> moBridge --TOSLINK--> APL1 --RCA-->MS-8 

So, the quuestion becomes - is it possible to use APL1 as both a room correction unit and a DAC?

And i am wondering what is the best way to do the measurements with APL1 while used in a tandem with MS-8:

- Do the autotune with MS-8, switch to stereo and turn off the rears, do the sweeps, apply FIRs and then switch back to Logic 7? This way, front speakers and a sub get the most correction. What happens to rears and a central channel is unknown. 

- Do the autotune, disable MS-8 processing, run sweeps with the APL1, apply FIRs and then re-do the MS-8 autotune? This way, we correct sound for the front speaker and a sub and then we recalivrate MS-8, central channel and rears get their correction too. 

- Any other ideas?


----------



## jb4674

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How much is this thing?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> Skimmed through the thread. Got all drooling and excited about this box, especially hearing good words about it from Hanatsu.
> 
> So i am currently an MS-8 user. I have 3 way active front, 2 way central channel with a 6" midbass, rears and a sub. I just love the Logic 7 and don't wanna lose it.


First, how do you do 3way+sides+2way cc+sub with 8 channels?
I guess you have an crossov3r for the cc, but also for the front between midranges and tweeters?





StabMe said:


> But... i wanna try these two devices in a tandem.
> 
> The thing is, in my 2007 Cayenne i get the sound signal from MOST optics which is converted by moBridge into TOSLINK, fed to a cheap DAC and then RCA'ed to MS-8.
> 
> Since APL1 has both digital and analog IOs, I would love to see the following signal path with APL1:
> 
> HU --MOST--> moBridge --TOSLINK--> APL1 --RCA-->MS-8
> 
> So, the quuestion becomes - is it possible to use APL1 as both a room correction unit and a DAC?


Yes, and it can also be used as a switch:
- digital and analog outs are always active
- digital in takes over analog when there's a signal
- there's a jumper to select what kind of digital in (optical or toslink)





StabMe said:


> And i am wondering what is the best way to do the measurements with APL1 while used in a tandem with MS-8:
> 
> - Do the autotune with MS-8, switch to stereo and turn off the rears, do the sweeps, apply FIRs and then switch back to Logic 7? This way, front speakers and a sub get the most correction. What happens to rears and a central channel is unknown.
> 
> - Do the autotune, disable MS-8 processing, run sweeps with the APL1, apply FIRs and then re-do the MS-8 autotune? This way, we correct sound for the front speaker and a sub and then we recalivrate MS-8, central channel and rears get their correction too.
> 
> - Any other ideas?


In both cases here you'll mess up your center channel, because it will receive some corrections (x2!) based on other driver's response (L&R only). Phase and amplitude would probably be completely off.

But there should be a way, I recently had both APL & ms8 for a month or two maybe, and they definitely worked very well together, but when they focus on the same channels.
I didn't have a center channel but I really enjoy L7 too, just for the surround with side & rears (I like it so much that I even tried 2xms8).


So for now only 2 ways I can think of:

1 - if you're ok to remove the cc of the equation (but still L7 with sides).
APL feeding the ms8, so its filters would impact everything behind, no big deal for sides I think. This way the filters would be optimum for L&R 3 way & sub
> Calibrate ms8 first, to the best possible, with EQ and sub boost if needed. (just don't change this later)
> Then put sides to zero, L7 to off, measure and "calibrate" APL, done.
You'll cascade the brain power of both units.
(it might not work for you, but it worked very well for me).

2 - if you really want to keep the CC:
Buy 2 APL1, one feeding the ms8, one dedicated to cc and sub so this time after the ms8.
> like in #1
> maybe put CC to 0 as well during front APL measurements
> then measure CC and sub independently for 2nd APL
That could probably be great too, but seems very complex to manage...


I'd start easy with 3 way + sub.
I still miss L7 sometime now, but the soundstage is so good now with APL that I can wait (I plan to re-insert the ms8 one day).


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> First, how do you do 3way+sides+2way cc+sub with 8 channels?
> I guess you have an crossov3r for the cc, but also for the front between midranges and tweeters?


Yes! Crossovers for central channel, for the front (mids and tweets), and rears are passive.






Elgrosso said:


> Yes, and it can also be used as a switch:
> - digital and analog outs are always active
> - digital in takes over analog when there's a signal
> - there's a jumper to select what kind of digital in (optical or toslink)


Nice to know. Thanks!



Elgrosso said:


> In both cases here you'll mess up your center channel, because it will receive some corrections (x2!) based on other driver's response (L&R only). Phase and amplitude would probably be completely off.
> 
> But there should be a way, I recently had both APL & ms8 for a month or two maybe, and they definitely worked very well together, but when they focus on the same channels.
> I didn't have a center channel but I really enjoy L7 too, just for the surround with side & rears (I like it so much that I even tried 2xms8).


Yeah, the central channel is a nice thing. I kinda got used to it so much and i'd hate to waste so much effort installing it. 



Elgrosso said:


> So for now only 2 ways I can think of:
> 
> 
> 
> 1 - if you're ok to remove the cc of the equation (but still L7 with sides).
> APL feeding the ms8, so its filters would impact everything behind, no big deal for sides I think. This way the filters would be optimum for L&R 3 way & sub
> > Calibrate ms8 first, to the best possible, with EQ and sub boost if needed. (just don't change this later)
> > Then put sides to zero, L7 to off, measure and "calibrate" APL, done.
> You'll cascade the brain power of both units.
> (it might not work for you, but it worked very well for me).
> 
> 2 - if you really want to keep the CC:
> Buy 2 APL1, one feeding the ms8, one dedicated to cc and sub so this time after the ms8.
> > like in #1
> > maybe put CC to 0 as well during front APL measurements
> > then measure CC and sub independently for 2nd APL
> That could probably be great too, but seems very complex to manage...


Well, yeah. 

But what if i let the MS-8 do the final tune? Turn the L7 and rears off, tune with APL1 and apply a FIR filter which resembles the curve that MS-8 tries to get to, then recalibrate with MS-8 again. In this case, MS-8 gets a very nice signal from the L/R fronts and sub, tunes the central channel and rears. 

I understand that a lot of the sound comes from central channel with L7 turned on, maybe more than 60%. That means that i won't be getting much help from APL1. 

Another way is two APL1s, yes. Or a CarPC with a VST host and APL1 plugin, which is gonna be cheaper, i guess.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> ...But what if i let the MS-8 do the final tune? Turn the L7 and rears off, tune with APL1 and apply a FIR filter which resembles the curve that MS-8 tries to get to, then recalibrate with MS-8 again. In this case, MS-8 gets a very nice signal from the L/R fronts and sub, tunes the central channel and rears.


Well think about it differently, it would still be like trying to apply a correction from your rear right driver to your front left woofer for example.

And ms8 cannot do the final tune, you'll need to set TA and XO on the ms8 to calibrate at least one time for the APL to get some measurements.
And it you want to recalibrate again once APL is in the loop, then you'll mess with its filters (based on first ms8 calibration %).


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> And ms8 cannot do the final tune, you'll need to set TA and XO on the ms8 to calibrate at least one time for the APL to get some measurements.


Um... yes. Well, almost. The process as i see it:
- do the initial setup with MS-8 with APL1 installed before it and turned to bypass mode.
- Switch MS-8 to stereo (L7 disabled), turn off the rears so only the front L/R and a sub are active. Disable processing.
- Do the sweeps
- Apply the APL1 filters with a house curve that maximally resembles what MS-8 tries to achieve. 
- Recalibrate MS-8 once again. MS-8 will detect a house curve that resembles what it tries to achieve and hopefully won't mess with it. Central and rear speakers will be corrected by MS-8, though.

Not optimal, i agree. Well, must be tested 



Elgrosso said:


> And it you want to recalibrate again once APL is in the loop, then you'll mess with its filters (based on first ms8 calibration %).


Not if processing is disabled. With this option, only XOs are active, i think.

But quite possible, such setup will just create a mess 

Thinking of a MacMini, 8 I/O channel sound card and a VST version of APL1. But with this setup i might just get rid of MS-8 as well and do the whole processing (including 5.1 matrix processing) on a CarPC. Not as convenient as MS-8 with time alignment and EQing, but this way it should sound better.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I see, well ms8 off will disable TA & EQ, so it's asking a lot from the APL but maybe.
alexstastruup has a passive front 3 way with APl I think, he might help.

Yeah try the macmini with APl, then I'll follow you soon 
But you could also try just one APL first


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In the APL1, after the main sweep for the L and R Channel, is it necessary to do the on axis (short) sweep in the car?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> In the APL1, after the main sweep for the L and R Channel, is it necessary to do the on axis (short) sweep in the car?


Not sure about the question, since there's no "main" sweep, but a bunch of them, no limit, so including on axis yes.


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Not sure about the question, since there's no "main" sweep, but a bunch of them, no limit, so including on axis yes.


Raimonds has suggested me to do additional sweep for "on axis" measurement for speaker that has a strong directivity
the result then become additional correction to the main sweep result

Is it necessary to do this step in car environment?
or somebody here already try this?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> Raimonds has suggested me to do additional sweep for "on axis" measurement for speaker that has a strong directivity
> the result then become additional correction to the main sweep result
> 
> Is it necessary to do this step in car environment?
> or somebody here already try this?


Ha ok so yes it could also be required, depending of your setup.
I think Hanastu had to correct some tweeters in waveguide on the dash like that (few posts older in this thread maybe?).


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Ha ok so yes it could also be required, depending of your setup.
> I think Hanastu had to correct some tweeters in waveguide on the dash like that (few posts older in this thread maybe?).


Thanks a lot for the info

:beerchug:
:2thumbsup:


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> Raimonds has suggested me to do additional sweep for "on axis" measurement for speaker that has a strong directivity
> the result then become additional correction to the main sweep result
> 
> Is it necessary to do this step in car environment?
> or somebody here already try this?


Yes, I did it twice in two different setups. 

I was tired of the HF output comming from the closest tweeter and the method worked for me. The result was amazing and very! audible. Sound was comming from everywhere. (Tweeters were mounted in the front door triangles - faced almost back). 

Second time I have tried the same procedure with the TW's placed close to the windshield at the angle of about 25 degrees from the on-axis position, meaning much less reflections from the side Windows and other surrounding surfaces. The result is almost neglictable. Rajmonds means it is ok, as efficiency of this extra-test is varying depending of the actual of placement of drivers.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Looking for help understanding these graphs.

Left Side:











Right Side:











Why is the yellow line tracking the response at the low end, but then goes straight on the upper range?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Did you use any options in the EQ frequency limiter? I guess it could give this kind of results


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

No. I don't think so.











Sent from my iPhone using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Must be the time window then


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I thought I was using the recommended window for cars?


Sent from my iPhone using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I use 50 or 100ms, usually 50.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Looking for help understanding these graphs.
> 
> Left Side:
> 
> Right Side:
> 
> Why is the yellow line tracking the response at the low end, but then goes straight on the upper range?


Hello,

It is because HF "limiter" is starting work too low (150Hz and 1kHz).
And this is caused by a dominance of a sub - too much it is.
What should be done?
Let`s reduce a sub by about 6 dB.
Than let`s use target curve with a setting "C" not "T"
and set HF limiter to such value that allows correction for a frequency band we need.
Good luck,


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I will turn off my subwoofer and try again.


I'm surprised that my subwoofer is too loud. Everyone who listens to the car at competitions says the sub is too low.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok, you may turn off your sub just for test.
But it should be better just to reduce its level.
Than you will have ability to tune a sub level to meet your preference target
after APL correction will be applied.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Looking for help understanding these graphs.
> 
> Left Side:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Right Side:



Also, what is going on at 3kHz?

It looks like a phase issue but that's not possible because I don't have a tweeter. The midbass and mid are crossed over at 400Hz LR24.

I tried with 2 different microphones, but the dip is still there. And it's on both left and right side. And since the mic is moved all over the interior of the car for 300+ measurements, it can't be a modal cancellation.

Any ideas?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In such case, the problem around 3 kHz looks like a speaker problem.
Let APL do its job on that problem.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

For anyone that have issues with tonality after the target curve has been applied:

I pointed this out in Elgrosso's build thread. It's very important to be aware of the midrange drivers upper response. Breakup nodes that ain't attenuated enough, using swallow lowpass slopes (i.e using midrange drivers beyond the omnidirectional range) might cause overcompensation in the correction curve. Measure your midrange drivers (left/right separately) to find out the power response of the driver. Tweeters which are mounted on-axis will be directional in the higher octaves and might require the on-axis correction mentioned in the manual.

Don't use acoustic lowpass slopes shallower than 24dB/oct, it will save you trouble IME.


Sent from my iPhone 6 using Tapatalk.


----------



## Inese

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> The order has been placed!
> 
> I only have 10 days off(not in a row) between now and the end of July, so let's hope I'll have the time to play with it before then.


Have You already tried? Results?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Do we need to do any sort of level matching with the software target curve and/or microphone input gain?

I did some measurements and loaded my FIR files but the music is distorted. It's like the EQ is boosted and clipping the signal.

I wish there were some more detailed instructions on the setup, measurement process and use of the APL Workshop software.

Also, I found that my preferred target curve (similar to the whitledge) is too tilted for the APL. It cuts off the graph display on the subwoofer end of the response. Is there a limit to the tilt of the target that can be used?

Lastly, what is the difference between using a curve as C vs T? I was trying to use a target curve as T, but then told to load the target as C instead.


Sent from my iPhone using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello,


subterFUSE said:


> Do we need to do any sort of level matching with the software target curve and/or microphone input gain?


No, there is no such connection.



> I did some measurements and loaded my FIR files but the music is distorted. It's like the EQ is boosted and clipping the signal.


Such thing is happening when signal source level is very close to Full Scale and there is no headroom for normal signal processing. Especially if digital input of APL1 is used. The input level should be decreased or FIR filter gain.



> I wish there were some more detailed instructions on the setup, measurement process and use of the APL Workshop software.


If QSG is too short, please ask for online support.



> Also, I found that my preferred target curve (similar to the whitledge) is too tilted for the APL. It cuts off the graph display on the subwoofer end of the response. Is there a limit to the tilt of the target that can be used?


The Workshop work environment is giving as wide possibilities to control curves. Please ask for a guidance if you like.



> Lastly, what is the difference between using a curve as C vs T? I was trying to use a target curve as T, but then told to load the target as C instead.


The overall finale result of use of correction or target curve is same.
The difference is only in the way as curves are displayed.
In "C" case, the target curve is applied on measured (green) curve.
In "T" case the target curve is applied on FIR filter curve (yellow) and you can see a difference between green and yellow curves that is exactly by target curve`s value.


Sent from my iPhone using Tapatalk[/QUOTE]


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You should look at the impulse response, that will show you disturbances during the measurement and will help you to chose correct gating. Increasing of time duration will assist to measure the low end more accurate but will at the same time less informative for the other ranges.

No matching is necessary if you use the same target curve. I use to apply 0-settings, but it is up to you. There is an option for this in the Workshop. You might find also other settings for the limiters (both at low and high end), which will not cut the measurements and the correction curve. If there is a big difference in dB between sub and TW, please try to re-test with the lower volume for the sub. it might work.

Flat curve in APL is not as flat as for other programmes. Hanatsu has made some comparison with REW as far as I remember. Tilt can not be adjusted automaticaly. You have to correct your target curve or make correction in the PEQ C1. Being connected to the unit, C1 is able to send these corrections directly to it and they will work immediately for you.

According to Raimonds, there is no difference between T and C settings. I used to apply T for target curves and C (or -C) for other corrections, calibration files for the mic and sound card, etc.

Please check if your calibration file for your microphone is individual one, not generic. My own experience showed that application of the in-built sound card from the laptop can and (in almost all cases) will spoil test results. My DELL computer had irregularity of about 12dB at some frequencies. The remedy was to buy an external sound card with 48V supply for the condenser microphone.

It helps also to understand what is going on if you repeat measurements with the uploaded FIR-filters. Let's start with the flat target curve. You should get deviations less than 1-3dB except some modal regions and defect drivers. If you experience that low or high end are not corrected by APL, one of the possible reasons could be wrong limiters during the first test. No need to measure again. Just change the values (max -20dB, as far as I remember) and calculate once more. Add new corrections and calculate one more time. No limits her. These limiters limit calculations - not measurements.

The last question - accuracy of the final results depend much of the noise level. APL works fine if the difference between a signal and floor noise is more than 25-30dB. 

Do not forget to make 3-5 tests for the same side and calculate average value for it. By this you will also see repeatibility, stability of the tested results and possible errors (technical and methodological). Do not place a mic too close to the emmitting drivers (typically 15-25cm distance is OK in a car). In order to get reflection information, all surfaces should be "painted" at the distance about 5cm. You might come to other values - just shearing my practical experience with the APL.

If IR-response shows significant level of distortions - try to reduce both in- and output signals. For the tests I use nomally HU volume level of 17-19 from 0-35 available. Sub - in the min position - then you will be able to add more LF if needed.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Such thing is happening when signal source level is very close to Full Scale and there is no headroom for normal signal processing. Especially if digital input of APL1 is used. The input level should be decreased or FIR filter gain.


Hi Raimonds!
I got this issue yesterday too, high distortion on the midranges.
I thought it was just too much boost since they're not so far of their FS (250Hz for FS of 170Hz).
But I use digital so maybe it was just the input level?
Where should I adjust it, before the APL (but how?) or just after into the DSP?





Raimonds said:


> The overall finale result of use of correction or target curve is same.
> The difference is only in the way as curves are displayed.
> In "C" case, the target curve is applied on measured (green) curve.
> In "T" case the target curve is applied on FIR filter curve (yellow) and you can see a difference between green and yellow curves that is exactly by target curve`s value.


I don't understand this... :/
"C" is applied to the measured curve (green), and "T" to the FIR filter created?
So C is IIR only, when T is FIR?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

APL uses only FIR filters. Some minimum phase problems could be solved automatically by implementing these filters. Funny to check this with the TDA software: (with and without APL) - just to see the difference.

If one has no possibility to attenuate the volume from the player/HU while connecting digitally to the APL, there is function in the Workshop called EQ zero level. Normally it is set to 0 dB as a default value. In the case of rather strong signal it is recommended to use at least -10dB for this setting. During the calculation procedure, the target curve will be put down accordingly and speakers will not be distored due to a missing headroom. Again - no new tests are needed - just re-calculation with the corrected EQ zero level value.

Regarding XO point for a midrange with the Fs=170 Hz is preferable to try to raise the filter level to 1,5-2 octaves, meaning at least 340Hz. This might help. Have you tested Thiele-Small parameters by yourself? Just to be sure that 170Hz is a correct value for your specific driver.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> APL uses only FIR filters. Some minimum phase problems could be solved automatically by implementing these filters. Funny to check this with the TDA software: (with and without APL) - just to see the difference.


I do this usually, much cleaner after APL, but not magic if the base is all over the places.
About C & T, if C is applied to the measurement, and T to the filter, I can see that they are interchangeable.
Is it this?





> If one has no possibility to attenuate the volume from the player/HU while connecting digitally to the APL, there is function in the Workshop called EQ zero level. Normally it is set to 0 dB as a default value. In the case of rather strong signal it is recommended to use at least -10dB for this setting. During the calculation procedure, the target curve will be put down accordingly and speakers will not be distored due to a missing headroom. Again - no new tests are needed - just re-calculation with the corrected EQ zero level value.


I see! I did this before with ms8.
I'll load my "best" C-dsp setting and will try that.





> Regarding XO point for a midrange with the Fs=170 Hz is preferable to try to raise the filter level to 1,5-2 octaves, meaning at least 340Hz. This might help. Have you tested Thiele-Small parameters by yourself? Just to be sure that 170Hz is a correct value for your specific driver.


So first I'll check if it's the signal.
But yes higher would be safer, it's just that I tried lowest possible for the stage.
Also there was no big difference between 300/350/400, they all happen just after a dip.
The XO has very little effect there, but below the dip at 280, it is noticeably different.
THD seemed ok though, even 200Hz/12db it read ok.
But I'm not sure this is reliable, usually the noise from around during the sweeps shows up there.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> If one has no possibility to attenuate the volume from the player/HU while connecting digitally to the APL, there is function in the Workshop called EQ zero level. Normally it is set to 0 dB as a default value. In the case of rather strong signal it is recommended to use at least -10dB for this setting. During the calculation procedure, the target curve will be put down accordingly and speakers will not be distored due to a missing headroom. Again - no new tests are needed - just re-calculation with the corrected EQ zero level value.



That sounds like the solution to my distortion issue. I am running the output from my mObridge DA1 into the APL1 at full volume to maximize the signal/noise.

So the APL is attempting to boost EQ but the signal is already at 100% FS.


I will try using the EQ Zero Level setting and see if this helps. Thanks!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Regarding signal/noise - 25-30dB should be OK for APL. Do not maximise everything during the measurements.

EQ zero level - I used it to make "digital volume control" for CD-changer connected by toslink to the APL. 6 presets with the same target curve but different level values (-10 ... -18 dB) and I am on the go. Out of 16 positions on the APL switch only 6 are used for this purpose. Rest - different target curves, etc.

These 6 steps in the volume control should actually be supplied with the correction based on the advanced loudness (izofons). Somehow, do not know how to make it in a best way yet. Deepness of such correction might be variable, so it is a clear optimization task, may be not worth spending time on


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In my car, I have a Mobridge DA1 preamp which has optical output. The OEM volume control still functions. Max volume = 34. But the max undistorted volume = 33.

I have set my gains with the OEM volume at 33, and the Helix Director at 0 dB unity.

Should I keep the OEM volume at 33, and use the EQ Zero Level to reduce the level of the target curve to prevent EQ boost in the APL1?


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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I would actually do the opposite: reduce the OEM volume and keep EQ zero level at 0.

In my case (Alpine-137BTi) clipping starts already at 29 (full range 0-35). Little bit unlukky with this. Tests I used to carry out at the level 17-19. This gives enough S/N ratio. Then listening music at 20-25 will not distore the system, but loud enough for me while driving. In your case might be different. But again - APL does not demand maximasing everything.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> I would actually do the opposite: reduce the OEM volume and keep EQ zero level at 0.
> 
> In my case (Alpine-137BTi) clipping starts already at 29 (full range 0-35). Little bit unlukky with this. Tests I used to carry out at the level 17-19. This gives enough S/N ratio. Then listening music at 20-25 will not distore the system, but loud enough for me while driving. In your case might be different. But again - APL does not demand maximasing everything.


My setup is fully digital since the MMI uses MOST fiber optics to communicate with the Bose factory amplifier. I have bypassed the Bose amp by using a mObridge DA1 preamp. The output from the mObirdge is Optical Digital, but the volume level is still adjustable from the MMI volume knob.

I have already set my amplifier gains with the MMI volume at 33/34 which is the max undistorted volume as measured via oscilloscope, and the DSP volume at 0 dB unity. This way I can play my system at full volume without the risk of clipping.


So you're suggesting I reduce the factory volume level now and allow the APL1 to boost EQ? Wouldn't it be better for the overall S/N ratio to leave the source volume at max undistorted level and then set the APL1 so that it will not boost the EQ into clipping?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Different choices are available. It is up to you. Ad soon as you know the problem ... After EQ by APL you might expect severe change in the output. So you need a headroom for this. Awaiting your results...

Sendt fra min GT-I9505 med Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Will try and report back.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Btw, the lower Eq target fixed the distortion issue.
So now I have to retry my "old best" XO combo, and probably optimize a bit more the target level.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Btw, the lower Eq target fixed the distortion issue.
> So now I have to retry my "old best" XO combo, and probably optimize a bit more the target level.




So using a target curve with lower level prevents APL from making EQ boosts?


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----------



## Hanatsu

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

I think you set it with "EQ Zero level". If you press "view as eq" and check the yellow curve it should move down as you lower this value. Just re-calculate the measurement.


Sent from my iPhone 6 using Tapatalk.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> So using a target curve with lower level prevents APL from making EQ boosts?
> 
> 
> Sent from my iPhone using Tapatalk


It will prevent from too much boosts, but it still boost, relatively less than before and it will cut more.
In my case maybe a bit too much, a lot of cut on dsp, a lot on APL, I'm getting close to miss some juice!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Juice - it is just to select correct target curve and appropriate volume level for listening after applying of FIR-filters. Using PEQ C1 one will be able to create his own desirable target curve. The reason I like APL - it is due to unlimited number of choices, freedom for selections and quick way to apload and listen corrected results.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yes a lot of flexibility! So I can easily get lost, so many interrelated variables


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Inese said:


> Have You already tried? Results?


I won't be home for another 2.5 weeks. If things go as planned, I will have VERY little time to play with it before hitting the road for another three weeks. The n I'll be home for four days and might have a real chance to play with it. 

That said, I spent a lot of time last week reading everything I could about APL Workshop, and I think the one thing missing is a step-by-step tutorial for the newbie.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right. It is not for newbees ....☺

Sendt fra min GT-I9505 med Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Dear friends,

Some words regarding an issue when the input of APL1 unit (digital or analog) is fed with FS signal level without any headroom.
It is impossible to use any equalizer on signal that has zero headroom.
Therefor you must add a headroom. 
1) by reducing signal source (feeding APL1 input) output level if possible,
2) by reducing APL1 FIR filter overall gain. Two ways are possible a) by setting "EQ zero level" to some negative value, -6 dB for example, b) by use of level slider of C1 tool

Please feel free to ask me support questions here or directly to me.

BR,

Raimonds


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Right. It is not for newbees ....☺
> 
> Sendt fra min GT-I9505 med Tapatalk



I might do that video after all...


Sent from my iPhone 6 using Tapatalk.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do that video after all...
> 
> 
> Sent from my iPhone 6 using Tapatalk.


That'd be great! 

I work with some pretty complex electronics(jumbotrons) so I'm sure I'd figure it out. It would probably also help clear up some the confusion people have about what to buy and what does what too.

FWIW, It took me just a few minutes to figure out TDA, but it's much simpler than Workshop.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Does anyone have any experience EQing HLCDs with APL1? Any special considerations to be taken?
Wonder how it would work out.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll be finding out when I get the time to install mine.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do that video after all...



That would be awesome.


----------



## piyush7243

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do that video after all...
> 
> 
> Sent from my iPhone 6 using Tapatalk.


That would be stellar

Sent from my Nexus 6P using Tapatalk


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll be recording a video the coming week, I'm in the middle of a large job right now. I'll try to include as much as possible ^^


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks man!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hanatsu, do you have experience with 2 subs (or 4 way) and APL?

I have the best summing on left when I invert one on the dsp (strange because they're both in rear seats).
I left it normal while measuring with APL thinking it will fix it.
But no it's still better after the filter if I reverse it myself again.

I'll try L+R instead of L/R on both sub inputs.


----------



## piyush7243

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I'll be recording a video the coming week, I'm in the middle of a large job right now. I'll try to include as much as possible ^^


Thanks man. Much appreciated

Sent from my Nexus 6P using Tapatalk


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Hanatsu, do you have experience with 2 subs (or 4 way) and APL?
> 
> I have the best summing on left when I invert one on the dsp (strange because they're both in rear seats).
> I left it normal while measuring with APL thinking it will fix it.
> But no it's still better after the filter if I reverse it myself again.
> 
> I'll try L+R instead of L/R on both sub inputs.


No, can't say I do. I will install a raspberry pi in my car later and will use APL for all channels instead, then I will learn... 

I think you should bypass sub and run them off the c-dsp only in the meantime. The SPFR method combined with 4096 taps limits the resolution in the lowest octaves. Good news is that the lower octaves are very easy to tune, it only requires a single measurement point and the response is valid over a pretty large space.

You can change the resolution in Workshop to get better accuracy in lower frequencies if you wanna use it as measurement software.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Good idea thx!
I tried 25/50/100 ms but it impacts mostly the highs.
It will be definitely be easier if I go back to 4 small subs everywhere.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ah not the window length, I meant the fft size.


Sent from my iPhone 6 using Tapatalk.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hum, is it the filter setting box? I don't remember something like that.
Or maybe TDAeq could be useful there.


----------



## whoever

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do that video after all...
> 
> 
> Sent from my iPhone 6 using Tapatalk.


That would make a difference, thank you!


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I might do that video after all...
> 
> 
> Sent from my iPhone 6 using Tapatalk.


You should, what a video can do in a few minutes takes hours to type out and post. 

By end of week I will post a review of the minidsp 2x4hd for everyone. 
I'm definitely going to do a video, with 7kids and full time job I just simply don't have the time to do a write up. Although it would be nice if I did , like the apl1 it really needs to be known how much of a diffrance a good fir filter set can do for all of us.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I've recorded much of the video. I need to edit and some stuff as well. Not home tomorrow, gonna drive across half the country to buy me an ATV so I'll probably have it done by Thursday/Friday


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Perfect, I leave either tomorrow or the next morning for work and won't be back until the end of the month. That'll give me plenty of time to watch and rewatch your video!


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> That'd be great!
> 
> I work with some pretty complex electronics(jumbotrons) so I'm sure I'd figure it out. It would probably also help clear up some the confusion people have about what to buy and what does what too.
> 
> FWIW, It took me just a few minutes to figure out TDA, but it's much simpler than Workshop.


Do you work FOH or a line rigger or what? Sounds kinda fun


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'm an LED video tech, I work on and manage the LPGA tour. I setup and run the big video screens for about half of the North American tournaments, I remotely assist the tech on the other half of the tournaments. I'm at the Walmart Championship right now.

When this tour slows down I go work other tournaments. The other tournaments start with LED screens and can include audio for the media centers, CCTV and other live entertainment. 

This was my work console at the BMW Championship last year:


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Haven't forgot about the the vid for you who wonder 

I didn't manage to finish the video before my vacation. I'm home on Monday again, I just have some editing left. I'll probably split it into two parts.


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Haven't forgot about the the vid for you who wonder
> 
> I didn't manage to finish the video before my vacation. I'm home on Monday again, I just have some editing left. I'll probably split it into two parts.


Very cool, take your time and make sure you're happy with it. However it turns out I will very grateful.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Haven't forgot about the the vid for you who wonder
> 
> I didn't manage to finish the video before my vacation. I'm home on Monday again, I just have some editing left. I'll probably split it into two parts.


If you need help editing, I'll be glad to lend my assistance if I can. Not sure what app you're using but I've used several.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Premiere and after effects. I tried sony vegas but didn't like it :/


Sent from my iPhone 6 using Tapatalk.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> Premiere and after effects. I tried sony vegas but didn't like it :/


I've used Premiere before but don't have a license. I can use the demo if you'd like some help and then send the file to you for final encoding.

David


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sooooooooooooooo. Just checking if there's an update on the video? 


Sent from my iPhone using Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

bumpity bump....


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I should be installing my APL-1 in the next week or two, it'd be awesome if that video were just about ready


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yeah. Mine has been installed for months but I can't tune it yet. LOL. I just have the bypass switch on.


Sent from my iPhone using Tapatalk


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am needing to buy one.


----------



## 1fishman

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



thehatedguy said:


> I am needing to buy one.


I'm interested also, but not until i think i'm up to tuning it, OR i could pay someone local to walk me through it.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Need a video. Or more complete instructions. I'm not a tuning novice and I'm baffled.


Sent from my iPhone using Tapatalk


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Got all of my software licensed and running last night...maybe I can come to the party soon.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I had mine installed for about 15 minutes, then decided to rebuild the dash and removed almost everything from the car. Hopefully I'll have it back in next week and will be able to fire it up.


----------



## brumledb

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have one BNIB that I am willing to part with, if anyone is interested shoot me a pm.


Sent from my iPhone using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



thehatedguy said:


> Got all of my software licensed and running last night...maybe I can come to the party soon.


Cool!
I thought you went for 2 mini hd instead, I must have misunderstood.
Let us know how it works for you!


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I had thought about it. But it seemed easier to do the APL1 with another processor- will go optical from the APL1 to the Helix, have remote for levels/sub level, and thought would be more automated...but that might not be the case after getting the software lol. But I believe Raimonds is doing something pretty ground breaking and want to be in on that.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Probably yes, especially with another dsp in the loop.
Honestly the process is not that hard, I can now tune now much faster with the APL than the mini (well after few months ).
But I still sometime use the mini for testing/learning effects of different settings with presets.

I too would like to go manual FIR like obaieo one day, just not ready yet.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I would sincerely appreciate a thorough tutorial on tuning the APL1. I have mine installed but deactivated because I can't figure it out. It's a paperweight to me at the moment.


Sent from my iPhone using Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

And I'm not a tuning novice by any stretch of the imagination. 


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----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

A tutorial doesn't even have to be a video, it could be a simple PDF like this one I made for a piece of software at work: https://www.dropbox.com/s/hhz5rlbcfk1o3jf/Pro Presenter Twitter Tutorial.pdf?dl=0

Raimonds sent me this video, but there is a bit of a language barrier: https://youtu.be/a9G820cg2Mc


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Isn't the fellow in the videos with the mustache Raimonds?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I threw the title into Google Translate and it has Raimonds name in the title, so I think so. I think the other guy might be Alextaastrup from this forum.

I also tried to have Google Translate handle the audio from the video, and that didn't really help much.


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Maybe someone could get Victor to translate.

Think you're right.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Here are a few fun results from Google Translate 




























So yeah, maybe Victor might help us...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'm not sure to understand what you're missing guys.
You should find everything you need in this thread especially but also few others from Han' or Alex, plus of course Raimonds himself per email.
Are you stuck on one specific step?


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I just bought brumledb's APL1 so I'll need to buy the software soon. I know I need the APL Workshop software but I'm confused by the APL TDA and APL TDA EQ software. Which of the second two is needed to be purchased and what is the difference between the two?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> I just bought brumledb's APL1 so I'll need to buy the software soon. I know I need the APL Workshop software but I'm confused by the APL TDA and APL TDA EQ software. Which of the second two is needed to be purchased and what is the difference between the two?


No need for anything else than "workshop".
TDA is nice to have because it's easy to use to optimize TA for ex, but not necessary.
TDA eq, that I never used, seems to be able to export fir filters as well.
But not based on the power response, so more like a regular "auto" tune.
Would be curious to hear the difference though.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just watched the video, and the second linked: https://m.youtube.com/watch?v=Ewxv8yLxxbg
Sure it would be nice to get translation! I'll see if I can ask one colleague.
It gives an idea of the "painting" method.
Also they seem to go with "coneq" directly.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> No need for anything else than "workshop".
> TDA is nice to have because it's easy to use to optimize TA for ex, but not necessary.
> TDA eq, that I never used, seems to be able to export fir filters as well.
> But not based on the power response, so more like a regular "auto" tune.
> Would be curious to hear the difference though.


Thanks sir!


----------



## tonny

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Can anyone explain the difference between the 3 tuning software versions you can buy on there website? 
I see the normal APL workshop, the APL TDA end the APL TDA EQ software... 

And which would give the best results?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



tonny said:


> Can anyone explain the difference between the 3 tuning software versions you can buy on there website?
> I see the normal APL workshop, the APL TDA end the APL TDA EQ software...
> 
> And which would give the best results?


Hi Tonny,
Thank you for questions!
Yes, "APL Workshop" is basic measurement and correction filter (equalizer) syntheses program to use with APL1 unit or EP1 VST plagin.
The APL TDA software is for "pre eq" tuning - to set up correctly crossover unit, its delays and to "see" harmonic distortion curves.
The APL TDA EQ software is using TDA process to create EQ but with much less measurement points as Workshop. It is intended to tune up a near field performance of studio monitors or any speakers in near field application and closely to speaker`s axes.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



1fishman said:


> I'm interested also, but not until i think i'm up to tuning it, OR i could pay someone local to walk me through it.





Elgrosso said:


> I'm not sure to understand what you're missing guys.
> You should find everything you need in this thread especially but also few others from Han' or Alex, plus of course Raimonds himself per email.
> Are you stuck on one specific step?


Feel free to ask support from me! All my customers are far from me and I am very trained to use Skype and TeamViewer for that : )))
And have nice results : )


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Feel free to ask support from me! All my customers are far from me and I am very trained to use Skype and TeamViewer for that : )))
> And have nice results : )


I apologize if this has been covered already. I am trying to see what the TDA trial is on the website. I downloaded the zip as well as whatever the newest MCR runtime is. After installing both. I dont get a EXE file or an icon or anything. Im not sure what im supposed to be doing to run the software. Do i need to have the actual mathlab or matlab software or what am i missing?


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Jscoyne2 said:


> I apologize if this has been covered already. I am trying to see what the TDA trial is on the website. I downloaded the zip as well as whatever the newest MCR runtime is. After installing both. I dont get a EXE file or an icon or anything. Im not sure what im supposed to be doing to run the software. Do i need to have the actual mathlab or matlab software or what am i missing?


Jscoyne2 
Just go to the folder that the installation created, inside you will have the .exe file

and for the MCR, don't use the newest, use the 8.1


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Im running a windows 10 computer and if i try to run the 8.1 compiler version. I get a error message saying "this version is not compatible", if i run a newer 2016 version, i get a cannot find 8.1 version .dll. 


so...is there no way to run the TDA software on windows 10?


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



neoysj said:


> Jscoyne2
> Just go to the folder that the installation created, inside you will have the .exe file
> 
> and for the MCR, don't use the newest, use the 8.1


^^

Sent from my SGH-T999 using Tapatalk


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Jscoyne2 said:


> Im running a windows 10 computer and if i try to run the 8.1 compiler version. I get a error message saying "this version is not compatible", if i run a newer 2016 version, i get a cannot find 8.1 version .dll.
> 
> 
> so...is there no way to run the TDA software on windows 10?


JScoyne2,
try to download the 64bit version (both for the TDA and MCR 8.1), cause most of the windows 10 runs in this enviroment

now I am running TDA in Windows 10


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Here is some discussion ...
http://www.diymobileaudio.com/forum/4205505-post11687.html


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Here is some discussion ...
> http://www.diymobileaudio.com/forum/4205505-post11687.html


Im not sure that goes where you think it does. Link goes to guy talking about his 94 bmw?

Sent from my SGH-T999 using Tapatalk


----------



## Jscoyne2

*Re: Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Here is some discussion ...
> http://www.diymobileaudio.com/forum/4205505-post11687.html


Nvm. Must be a tapatalk error. For anyone on tapatalk. The link goes to the jbl-ms8 thread

Sent from my SGH-T999 using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

APL processing on Android devices.

The world of mini PC and Android is developing and its computing power as well. The APL also goes further and starts its Android era. Everyone who uses Android now can also use the APL product with all its high quality and significant options. The APL–Android compatibility pack is already here for customers. It provides a way to implement the APL`s processing into any Android device. The sound quality stays the same as it is when the APL equalizer unit is being used with some new options available. 

The APL tools and solutions are mostly developed for professionals and are used by sound specialists that is why they require some professional skills. And it would be a good idea to ask about tuning and setup service to someone who knows the nuances. It may be a APL representative or our client who is around and already uses the APL tools. 

Car sound enthusiasts are very important customers because the car sound environment is most challenging and Android devices have become a very popular media source for car.

The APL has a lot of experience doing detailed loudspeaker corrections and working with the most demanding professionals. Our first public presentation was in 2006 at San Francisco AES convention. We showed the world that it was possible to tune the sound of various loudspeakers to the same reference. 

Please contact us, our representatives or our customers to see how it works and how APL products can suit exactly to your needs!


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Meaning what exactly? Are you talking about plugging in your phone to your apl1 hardware instead of a laptop?

The Dirac and IIR/Fir filters needs the powerful shark processor that I think(?) Is far more powerful than what is in todays phones. Idk howd you make it a phone app only. How is this being implemented? Take measurements and processing is done on a mainframe and sent back to the phone?

Sent from my SGH-T999 using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Today`s mini PCs, tablets and carPCs are capable to process not only 2 channels of APL FIR processing with their 4 core, 1.8GHz processors.
You still must use ordinary PC with Workshop software to make the measurement and generate filter files. Than you can use that filters in Android device to process playback.


----------



## tonny

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is there also an version for the iPhone on it's way?


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Today`s mini PCs, tablets and carPCs are capable to process not only 2 channels of APL FIR processing with their 4 core, 1.8GHz processors.
> You still must use ordinary PC with Workshop software to make the measurement and generate filter files. Than you can use that filters in Android device to process playback.


How is this going to be priced as the apl1 hardware itself is quite expensive. Is this going to be an app that lets you play your music as well as bypassing many of the bad android internal DACS all while doing apl processing? Is it gonna be aux out or usb out? 

Should I just shut up and wait for more info? 

Sent from my SGH-T999 using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> APL processing on Android devices.
> 
> The world of mini PC and Android is developing and its computing power as well. The APL also goes further and starts its Android era. Everyone who uses Android now can also use the APL product with all its high quality and significant options. The APL–Android compatibility pack is already here for customers. It provides a way to implement the APL`s processing into any Android device. The sound quality stays the same as it is when the APL equalizer unit is being used with some new options available.
> 
> The APL tools and solutions are mostly developed for professionals and are used by sound specialists that is why they require some professional skills. And it would be a good idea to ask about tuning and setup service to someone who knows the nuances. It may be a APL representative or our client who is around and already uses the APL tools.
> 
> Car sound enthusiasts are very important customers because the car sound environment is most challenging and Android devices have become a very popular media source for car.
> 
> The APL has a lot of experience doing detailed loudspeaker corrections and working with the most demanding professionals. Our first public presentation was in 2006 at San Francisco AES convention. We showed the world that it was possible to tune the sound of various loudspeakers to the same reference.
> 
> Please contact us, our representatives or our customers to see how it works and how APL products can suit exactly to your needs!


Interesting news!
I have few droid’s phones at work that I could try.
Is there any tuning feature in this app, for on the fly?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The solution for iPhone is not so far.

The Android solution is intended to be an economy class solution. It is replacing APL1 unit
It is for free for Workshop`s clients for two places of installation.

The original DACs of Android device should be bypassed by use of HDMI digital audio output part as first idea.
MiniPCs and tablets have it. CarPCs should also have.



Elgrosso said:


> Is there any tuning feature in this app, for on the fly?


Yes!


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Pretty cool Raimonds! Nice foward thinking.

Maybe a tablet with my Song GS9 would be a complete solution...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> The solution for iPhone is not so far.
> 
> The Android solution is intended to be an economy class solution. It is replacing APL1 unit
> It is for free for Workshop`s clients for two places of installation.
> 
> The original DACs of Android device should be bypassed by use of HDMI digital audio output part as first idea.
> MiniPCs and tablets have it. CarPCs should also have.
> 
> 
> Yes!


Yes nice step! I'll contact you
Is there potential for more than 2 channels with hdmi?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Yes nice step! I'll contact you
> Is there potential for more than 2 channels with hdmi?


Yes of course : ) There is potential for more than 2 channels!
I would like to see some voting to understand how many supporters APL will have in such direction ...


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Yes of course : ) There is potential for more than 2 channels!
> I would like to see some voting to understand how many supporters APL will have in such direction ...


Me me me me me

Sent from my SGH-T999 using Tapatalk


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Yes of course : ) There is potential for more than 2 channels!
> I would like to see some voting to understand how many supporters APL will have in such direction ...


Fir processing is rediculously powerful but 95% of us dont understand how or why it works. If you bring fir processing to android. I think you might find a new market. Hard to say. I wish people on here would go more in depth in how it works. All the explanations ive seen are biquad this and biquad that and way over the general populaces head. Its almost like auto tune when used right though. Its totally cheating.  



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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

This is exactly correct. I have had an APL1 in my car for months and never could figure out how to tune it, and therefore I have it disabled and never used it.

The instructions are so vague. The tutorial that was posted here is a nice start but not in depth enough for me to understand how to get it working.


Sent from my iPhone using Tapatalk


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

In my case, it would be competing against something in the Helix camp of the Audiotec-Fischer line up. Currently an 8-channel DSP. Having experienced the limitations of IIR, I'm certainly intrigued. But I too would need some self-education how tuning the system would change. 

Sent from my iPhone using Tapatalk Pro


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In the Pro Audio world, FIR filters have been a big hit. Many of the Pro DSP units offer FIR now. They are typically used to flatten the response of a speaker cabinet with multiple drivers. For example, let's say A company builds a speaker with a horn and a bass driver in a single cabinet. You can buy that speaker and then tell the manufacturer which DSP you have and they will send you the FIR filters to make that cabinet perfectly flat in response with a linear phase crossover. Then you put that cabinet into your venue and use the input EQ to adjust the tonality to taste or EQ the room.

In the pro audio world the FIR filters typically don't have more than 1024 taps, however. This is because more taps = more delay in the sound. Since most pro audio setups are for live music, long delays in the sound make it difficult to perform. You would basically be singing and then hear yourself on delay from the speakers which can get distracting.

So 1024 taps is generally considered a limit for a live PA system with FIR.


For a playback system more taps is ok because the delay won't be noticeable. More taps is better because as you get more taps you can have better resolution of the EQ in the lower frequencies.
APL1 has 4092 taps.


It does not replace your DSP. You still need the DSP for crossovers.

My general idea for how it works is that the APL can go in front of the DSP and essentially act like an input EQ on a pro audio DSP. You then use the DSP output EQ and crossovers to build your active crossovers for your drivers and then the APL can be used to apply a target curve and fix phase across the spectrum.

My issue is that I've never been able to understand how to work the software well enough to get it working.



Sent from my iPhone using Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I think I have an idea of how to use my APL now, but with ha;f the gear out of my car, it'll be awhile before I can actually play with it.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The problem I was having was that I set up my audio system to use only digital inputs on my DSP, and therefore I set my amplifier gains based on the DSP receiving a full level digital signal from my mObridge DA1.

When I added the APL1 and ran the software, it created EQ boosts which caused the music to sound like distorted garbage.

I was told to lower the volume on the mObridge, but I don't think this is the proper solution because then I'm going to have to redo the gains throughout the entire system and that's going to completely change the balance of my speakers so they would have to be EQ'd all over again.

That's the part I just don't get. There needs to be a procedure to setting up a full system when using the APL1.


I'm starting to think maybe the way it needs to be done is to EQ your speakers one-by-one and make them perfectly flat. Then apply your crossovers. And then use the APL1 to apply the target curve and let it fix any phase anomalies.

I don't think we would be using the FIR filters in the same way that they are used for pro-audio setups. In pro-audio, the speaker manufacturer takes their cabinet and puts it in a large room and measures it. They window the response so that all reflections are taken out of the measurement, which basically means it's like an anechoic measurement. Then they use FIR filters to build a perfect linear phase crossover for that speaker cabinet. You can then load those FIR filters and your speaker will be perfectly flat and in phase. But then you stick that speaker in a room and need to apply more EQ for tonality and room EQ. They do this with the input EQ banks on pro audio DSPs.

But, in a car, we can't really do it that way. The pro guys can do this because they are making a fixed speaker cabinet, where the individual drivers will always be oriented the same no matter where you put the cabinet. If we take the speakers out of the car, then we can't really put them in the same orientation to one another to get an anechoic measurement.


Also, in order to do like the pro-audio guys, you would need the FIR filters on the output side of the DSP. That way you could apply different filters to the drivers and build a crossover. So, in this case, it would mean multiple APL1 devices going after the DSP outputs.

So that's why I'm leaning towards the APL being used more like an input EQ. And that's what input EQ is used for on pro-audio DSP. They use output EQ to correct the speakers. And Input EQ is used for correcting the room, and for applying a desired tonality curve to the sound.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> In the pro audio world the FIR filters typically don't have more than 1024 taps, however. This is because more taps = more delay in the sound. Since most pro audio setups are for live music, long delays in the sound make it difficult to perform. You would basically be singing and then hear yourself on delay from the speakers which can get distracting.
> 
> So 1024 taps is generally considered a limit for a live PA system with FIR.


Interesting, I had no idea. But what is the typical delay induced to be that noticeable?





subterFUSE said:


> The problem I was having was that I set up my audio system to use only digital inputs on my DSP, and therefore I set my amplifier gains based on the DSP receiving a full level digital signal from my mObridge DA1.
> 
> When I added the APL1 and ran the software, it created EQ boosts which caused the music to sound like distorted garbage.
> 
> I was told to lower the volume on the mObridge, but I don't think this is the proper solution because then I'm going to have to redo the gains throughout the entire system and that's going to completely change the balance of my speakers so they would have to be EQ'd all over again.
> 
> That's the part I just don't get. There needs to be a procedure to setting up a full system when using the APL1.


I had the same big distortion at the beginning, since it could boost more than 10db in some places, but tweaking the EQ target levels fixed it (APL1 feeding minidsp C-dsp).




subterFUSE said:


> I'm starting to think maybe the way it needs to be done is to EQ your speakers one-by-one and make them perfectly flat. Then apply your crossovers. And then use the APL1 to apply the target curve and let it fix any phase anomalies.
> 
> I don't think we would be using the FIR filters in the same way that they are used for pro-audio setups. In pro-audio, the speaker manufacturer takes their cabinet and puts it in a large room and measures it. They window the response so that all reflections are taken out of the measurement, which basically means it's like an anechoic measurement. Then they use FIR filters to build a perfect linear phase crossover for that speaker cabinet. You can then load those FIR filters and your speaker will be perfectly flat and in phase. But then you stick that speaker in a room and need to apply more EQ for tonality and room EQ. They do this with the input EQ banks on pro audio DSPs.
> 
> But, in a car, we can't really do it that way. The pro guys can do this because they are making a fixed speaker cabinet, where the individual drivers will always be oriented the same no matter where you put the cabinet. If we take the speakers out of the car, then we can't really put them in the same orientation to one another to get an anechoic measurement.
> 
> 
> Also, in order to do like the pro-audio guys, you would need the FIR filters on the output side of the DSP. That way you could apply different filters to the drivers and build a crossover. So, in this case, it would mean multiple APL1 devices going after the DSP outputs.
> 
> So that's why I'm leaning towards the APL being used more like an input EQ. And that's what input EQ is used for on pro-audio DSP. They use output EQ to correct the speakers. And Input EQ is used for correcting the room, and for applying a desired tonality curve to the sound.


Agree, and same goes for Dirac, but after trying different methods like:
1 - optimize the system to flat (or any target but flat is easier) with all the DSP power available (XO, TA, PEQ) then let the APL fix all other anomalies + the final target.
2 - do the minimum on the dsp (ball park TA, XO and no EQ) and let APL to fix everything.
I got better results with #2, almost like if some agressives PEQs applied first could either fix or create more problems for the APL (in the time domain I guess).
And it's also a lot faster…

But now I want to try another method, a bit of both, focused on XO.
I mean with either APL or Dirac I believe that the most important part is to create a baseline that can accept safely any boost anywhere, so XOs are the most important.
Next time I will try to use all the dsp power to be sure all drivers don't play even a little out of their bandpass, but won't EQ anything "in" their bandpass.
I just started by using aggressive filter slope like 48db but it is not always enough, and I still have to compare the effect with 24db.
Because it's kind of hard to finetune both units with measurement methods that are not exactly the same.
For this Dirac is a lot easier to reproduce with REW (8 sweeps).


----------



## subterFUSE

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

The calculation for amount of delay in an FIR filter is as follows:

(N - 1) / (2 * Fs) = Delay


where N = # of taps and Fs = sample frequency



So... in the case of the APL1 which operates at 48kHz and has 4096 taps.

(4096 - 1) / (2 * 48kHz)

4095 / 96,000 = .0426 s

.0426 s = 42 ms



That's way too much delay to be acceptable in a live sound reinforcement system. It's ok for a playback system like our cars or your home stereo, but it would be impossible for a live performer to deal with that kind of delay unless their hearing was totally isolated from the audio system. This is why you so often see performers wearing in-ear monitors. It helps them isolate the sound reinforcement system from their own voice and playing.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Makes sense, thx!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Agree, and same goes for Dirac, but after trying different methods like:
> 1 - optimize the system to flat (or any target but flat is easier) with all the DSP power available (XO, TA, PEQ) then let the APL fix all other anomalies + the final target.
> 2 - do the minimum on the dsp (ball park TA, XO and no EQ) and let APL to fix everything.
> I got better results with #2, almost like if some agressives PEQs applied first could either fix or create more problems for the APL (in the time domain I guess).
> And it's also a lot faster…


Isn't #2 pretty much what Raimonds recommends? Get it as close as possible with just the XO and TA on the processor(s) after the APL, then use the APL to EQ and deal with phase issues.


----------



## Beckerson1

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Isn't #2 pretty much what Raimonds recommends? Get it as close as possible with just the XO and TA on the processor(s) after the APL, then use the APL to EQ and deal with phase issues.


But wouldn't one need to balance out the individual driver sets? Especially those running only a L and R input from the source unit. As we all know the individual outputs of each speaker can be quite different. 

Or is this essentially somehow taken care of using the APL or DIRAC offerings? 

I know Elgrosso kinda hit on this already. I just dont see how


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Isn't #2 pretty much what Raimonds recommends? Get it as close as possible with just the XO and TA on the processor(s) after the APL, then use the APL to EQ and deal with phase issues.


Yes it is!




Beckerson1 said:


> But wouldn't one need to balance out the individual driver sets? Especially those running only a L and R input from the source unit. As we all know the individual outputs of each speaker can be quite different.
> 
> Or is this essentially somehow taken care of using the APL or DIRAC offerings?
> 
> I know Elgrosso kinda hit on this already. I just dont see how


Right I forgot individual levels!
And since there was no EQ I especially paid attention around the XOs while not caring about huge peaks in the bandpass.
Global L/R variations being managed by the APL or Dirac.


----------



## Beckerson1

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Yes it is!
> 
> 
> 
> 
> Right I forgot individual levels!
> And since there was no EQ I especially paid attention around the XOs while not caring about huge peaks in the bandpass.
> Global L/R variations being managed by the APL or Dirac.


Ok that makes more sense.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Isn't #2 pretty much what Raimonds recommends? Get it as close as possible with just the XO and TA on the processor(s) after the APL, then use the APL to EQ and deal with phase issues.



The problem is, you can't really build a proper crossover unless the speakers have a flat response. Flattening the speaker response needs to happen first, then you can add the crossover filters and they will have a predictable nature.

Once you have flattened the speaker response, and then built the crossovers, now it's time to apply the tonality curve you want. Pro-Audio DSPs make this easy by having separate EQ banks on the Input side and Output side of the crossovers. The output EQ is used to flatten the response of each individual driver. Then you make your crossovers. And then you use the Input EQ to flavor the sound however you like, or to correct for room issues.

Car audio DSPs have not caught up to the pro-audio world yet. Some are getting close, like Helix. But they still have work to do. The tuning process on a pro DSP is so much easier because of the ability to break the process up into parts, and have separate EQ banks to handle different jobs.


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I thought eqing outside the passband messed with phase after your crossover

Sent from my SGH-T999 using Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Have you guys ever read posts about "Acoustic" crossovers vs. "Electric?"

What is meant by this is that sometimes when you apply an electrical filter to a speaker, the resulting acoustic response does not always equal the predicted result. For example, you have a speaker and you apply a 12 dB Butterworth filter at 500 Hz. But the resulting frequency response from that speaker ends up being closer to 24dB slope. That's because the speaker's natural response combined with the electrical filter you just applied yields a specific acoustic result that is different than the electrical filter.

Well, if you EQ the speaker flat then when you apply an electrical filter then the acoustic result will be the same as the electrical filter setting. This is very well known and understood among the pro-audio engineers of the world. That's why when it comes to tuning their systems, they always begin by isolating the speaker from the room and then making the response perfectly flat. Then they build crossovers, and the last step is to put the speaker in the room and do another round of EQ to correct the room issues and to make the tonality sound pleasing.

The first part of this process is pure science. The second part is art.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Jscoyne2 said:


> I thought eqing outside the passband messed with phase after your crossover
> 
> Sent from my SGH-T999 using Tapatalk




Yes, it does. But it will actually help smooth out your phase response if the EQ is done to flatten the response.


In the most basic sense, that's what FIR filters are doing. They take a measurement of a speaker's response, and then make an inverted copy of that response and turn that inverted response into an EQ. When you perfectly invert a speaker's response, you have effectively made it flat.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> The problem is, you can't really build a proper crossover unless the speakers have a flat response. Flattening the speaker response needs to happen first, then you can add the crossover filters and they will have a predictable nature.
> 
> Once you have flattened the speaker response, and then built the crossovers, now it's time to apply the tonality curve you want. Pro-Audio DSPs make this easy by having separate EQ banks on the Input side and Output side of the crossovers. The output EQ is used to flatten the response of each individual driver. Then you make your crossovers. And then you use the Input EQ to flavor the sound however you like, or to correct for room issues.
> 
> Car audio DSPs have not caught up to the pro-audio world yet. Some are getting close, like Helix. But they still have work to do. The tuning process on a pro DSP is so much easier because of the ability to break the process up into parts, and have separate EQ banks to handle different jobs.


Well until now I used mostly Jazzi's method (and Hanatsu).
So always combinations of XO+PEQ to get to a specific target per driver, acoustically.
Usually filters were applied roughly one or two octaves below and above each crossover points to get something clean.
And it just appeared that too much optimization before APL/Dirac could do more harm than good sometime, I don't know why.

I understand the value of what you described but I don't see how to do it in a car.
Do guys in pro world have to manage less FR variations maybe?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



> Fir processing is rediculously powerful but 95% of us dont understand how or why it works.


Almost all manufactures, that offer FIR, do not know what to do with it and its power. It is just fashion to add FIR and make some „product” more attractive. It’s cheating.

Thus the use of FIR is reasonable only in case when its power and accuracy is requested – to create very accurate predistortions that exactly reflect to distortions of system. If they will not accurately reflect – you will have new additional distortions.
Therefore you need trustable measurement to implement such idea and it is possible when the measurement and FIR use are integrated in a one complete solution.


APL tools are not a panacea to errors you made in your setup and tuning. You should fix up everything you can with ordinary methods and make you system as nice as possible. It is good to use curves of Workshop and TDA to do that.
Some example. I have customer Peter. Hi is a doctor surgeon. And here are curves of Workshop’s first measurement of his BMW. Hi got this just by his own efforts.
















I am not usually suggesting to use APL1 unit in such well tuned setups because the client do not ketch improvement. But not in case with Peter. Peter was very happy with the result served by APL1 unit. 

Another story is with different BMW. It has two volumes connected by some kind of pipe for a midbass loudspeaker. And that volumes and pipe are creating resonator on about 200 Hz and making very sharp and deep notch. It is impossible to equalize it properly but the partial measure is to reduce correcting peak by 2 times. That gives as not ideal but usable result.




> The problem I was having was that I set up my audio system to use only digital inputs on my DSP, and therefore I set my amplifier gains based on the DSP receiving a full level digital signal from my mObridge DA1.
> 
> When I added the APL1 and ran the software, it created EQ boosts which caused the music to sound like distorted garbage.


It is very popular mistake and is caused by “volume war”. Every sound system must have signal headroom. Usually and normally it is 16 dB. The “volume war” is pushing everything to FS (full scale) making headroom zero. You can’t do any signal processing without headroom! You must supply it! It must be done by a proper gain distribution in your system. On of tools to do that is to reduce APL1 filter’s gain. That allows to feed APL1 input with FS signal.




> So, in this case, it would mean multiple APL1 devices going after the DSP outputs.





> The problem is, you can't really build a proper crossover unless the speakers have a flat response. Flattening the speaker response needs to happen first, then you can add the crossover filters and they will have a predictable nature.


Yes, it is very powerful idea to equalize each band after crossover or even put together crossover and eq filters in one FIR. But it is expensive : )))



> In the pro audio world the FIR filters typically don't have more than 1024 taps, however. This is because more taps = more delay in the sound. Since most pro audio setups are for live music, long delays in the sound make it difficult to perform. You would basically be singing and then hear yourself on delay from the speakers which can get distracting.
> 
> So 1024 taps is generally considered a limit for a live PA system with FIR.





> So... in the case of the APL1 which operates at 48kHz and has 4096 taps.
> (4096 - 1) / (2 * 48kHz)
> 4095 / 96,000 = .0426 s
> .0426 s = 42 ms


It is very incorrect statement. 1024 taps can not serve LF equalization at all.
But the delay introduced by FIR filter depends on how it is created.
APL1 unit has 4096 coefficients FIR filters that are able to serve EQ even on 30 Hz and FIR filters generated by Workshop have 0 latency/delay.
The overall latency of APL1 unit is just 1.8ms caused by converters



Dear APL customers! You have option to use *the online in person training* that will give answers on any questions and give you first sounding result. If you did not use that, it is up to you …



BR,

Raimonds


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I don't have a APL1 but I am getting a Dirac , but I am a FIR user and use open DRC like accurite 
And I can imagine the issues you guys describe...

When I eq I have the best results turning crossover down two oactaves into the stop band .than eq each driver to be flat at least one oactave past crossover. That will make your acoustic slope match your electric slope, But the key is to eq the driver using a close mic measurement to speaker. Than do your FIR biz , than eq whole system with a single eq With mic at listening position. That way the harmonics of the room and the eq harmonic changes in between drivers are not un-balanced. 


So maybe do your pre tune with close mic measurements on each driver. Than set TA than run your apL software Dirac or room eq ...

That's how I do it and it works. (And set your limits to not allow more than 3db boost. Or however you have to manipulate things so nothing is boosted a **** ton.) even a digital signal has a headroom and is not infinite. 

I was having a hell of a hard time getting all my input/output Eqs to sound as harmonically balanced as a single 31band eq and nothing else with a mic measurement from listening position with a basic 30band RTA.

Yeah the old skool method sounded much much more balanced until I learned this routine .


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

And fir was supposed to make tuning easier...

Sent from my SGH-T999 using Tapatalk


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What raimonds said is also true 

You can have a 2020 tap filter that will be 10.51ms or more (or less if you hack the impulse to be band limited) depending on windowing and centering the impulse. Filter length isn't fixed on amount of taps. There is a formula out there that will give you the MAX length for a filter based on how many taps but that filter may very well be shorter depending again on window used and centering of the impulse. 

1024 taps however can do some LF correction in phase only, pretty useless in phase plus mag , but to linearize a IIR crossover even a 1024t 96k can get down to at least 50hz 

Much below 50hz 1024t just falls short unless you run at 44k than you could squeak into the high 30s I suppose.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> I don't have a APL1 but I am getting a Dirac , but I am a FIR user and use open DRC like accurite
> And I can imagine the issues you guys describe...
> 
> When I eq I have the best results turning crossover down two oactaves into the stop band .than eq each driver to be flat at least one oactave past crossover. That will make your acoustic slope match your electric slope, But the key is to eq the driver using a close mic measurement to speaker. Than do your FIR biz , than eq whole system with a single eq With mic at listening position. That way the harmonics of the room and the eq harmonic changes in between drivers are not un-balanced.
> 
> 
> So maybe do your pre tune with close mic measurements on each driver. Than set TA than run your apL software Dirac or room eq ...
> 
> That's how I do it and it works. (And set your limits to not allow more than 3db boost. Or however you have to manipulate things so nothing is boosted a **** ton.) even a digital signal has a headroom and is not infinite.
> 
> I was having a hell of a hard time getting all my input/output Eqs to sound as harmonically balanced as a single 31band eq and nothing else with a mic measurement from listening position with a basic 30band RTA.
> 
> Yeah the old skool method sounded much much more balanced until I learned this routine .


Wow, so you mean you do your XOs with mic in front of the cones/mouths?
That’s interesting, and must be much easier.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Wow, so you mean you do your XOs with mic in front of the cones/mouths?
> That’s interesting, and must be much easier.


NO, I flatten the responce of the driver with the crossover either off or two oactaves past XO, I only work on the stop band , the pass band I use global eq for... the actual crossover point is determined at listening position by what sounds the best based on stage height depth and overall accuracy and by what measures good and is safe for the driver.


The close mic measurements are strictly for stop band . I find it sounds better to flatten the curve with crossover off/moved away than apply the filter. It will make the acoustic slope match the electrical slope

Before I did the same think except I was using measurements at listening position. That added room issues to measurements so a close mic measurement eliminated that so it didn't mess up the harmonic balance with rest of system. If I kept the old way I wouldn't be "fixing the acoustic slope" it would be fixing the slope with room stuff added. At that point it wasn't truly fixing the slope. 

Close mic for adjusting your crossovers with eq. Listening position for gloabal eq. if I do make an adjustment to a drivers passband in driver peq than I add that to all other speakers. But I try to avoid it and just use input eq for making flat FR and speaker eq for fixing slopes. Both different mic locations for different things. 

Sorry I don't post much screenshots. Maybe I should . Just time consuming...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> NO, I flatten the responce of the driver with the crossover either off or two oactaves past XO, I only work on the stop band , the pass band I use global eq for... the actual crossover point is determined at listening position by what sounds the best based on stage height depth and overall accuracy and by what measures good and is safe for the driver.
> 
> 
> The close mic measurements are strictly for stop band . I find it sounds better to flatten the curve with crossover off/moved away than apply the filter. It will make the acoustic slope match the electrical slope


Ok I think I see, kind of what described subterFUSE then. But mixing nearfield and listening position.
But first, question for confirmation: bandpass = between XO points, stop band = below & Above XO points?

In fact there's a lot of similarities with what I was trying to do with Dirac recently (and APL before).
Meaning focusing PEQ+XO to get to the acoustic slope, on the stop & transitions band, and leave the FIR device focusing on the bandpass.
Well with these actual words it seems much simpler.

But I never used near-field measurements for anything else than just checking the driver.
I'll have to give it a go, it will simplify the process, less steps, less time.
(yesterday with all these sweeps on such a large area I got lost at one time, what to EQ what not)





oabeieo said:


> Before I did the same think except I was using measurements at listening position. That added room issues to measurements so a close mic measurement eliminated that so it didn't mess up the harmonic balance with rest of system. If I kept the old way I wouldn't be "fixing the acoustic slope" it would be fixing the slope with room stuff added. At that point it wasn't truly fixing the slope.
> 
> Close mic for adjusting your crossovers with eq. Listening position for gloabal eq. if I do make an adjustment to a drivers passband in driver peq than I add that to all other speakers. But I try to avoid it and just use input eq for making flat FR and speaker eq for fixing slopes. Both different mic locations for different things.
> 
> Sorry I don't post much screenshots. Maybe I should . Just time consuming...


How close do you measure?
And how do you do for the HF drivers? (for flat)

Also I must say, I'm getting confused.
- after all these readings from Andy on how we should EQ the whole system (drivers+car reflections).
Yet here you're removing some of these effects of the equation.
- but in the same time I can see some value, maybe just trade-offs or for better balance like you said.
- and I'm close to think that these points were the ones blocking me before.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Ok I think I see, kind of what described subterFUSE then. But mixing nearfield and listening position.
> But first, question for confirmation: bandpass = between XO points, stop band = below & Above XO points?
> 
> In fact there's a lot of similarities with what I was trying to do with Dirac recently (and APL before).
> Meaning focusing PEQ+XO to get to the acoustic slope, on the stop & transitions band, and leave the FIR device focusing on the bandpass.
> Well with these actual words it seems much simpler.
> 
> But I never used near-field measurements for anything else than just checking the driver.
> I'll have to give it a go, it will simplify the process, less steps, less time.
> (yesterday with all these sweeps on such a large area I got lost at one time, what to EQ what not)
> 
> 
> 
> 
> 
> How close do you measure?
> And how do you do for the HF drivers? (for flat)
> 
> Also I must say, I'm getting confused.
> - after all these readings from Andy on how we should EQ the whole system (drivers+car reflections).
> Yet here you're removing some of these effects of the equation.
> - but in the same time I can see some value, maybe just trade-offs or for better balance like you said.
> - and I'm close to think that these points were the ones blocking me before.



To take what I said and add some common sence in your own way and your own system. Your gain structure will be different than another and you will know how your amps and equipment like to be gained. So use good judgment and steer clear of large amounts of boost when there's already a strong signal going in/out. There's barely any digital headroom, in most recordings post y2k.

So in general when tuning your system for good balance there is a way with all the various in/out eqs.

My method works in my system and makes sence acoustically for my system and previous renditions on how I like things to sound. 1st off I undergain my amps. I think it sounds better and I like all analog signals going in to be there max without clipping. Just how I roll.

But as far as what I meant , if you have let's say a cdsp and you have input eq and output eq. 

If your tuning the system as a whole you don't want to turn down any frequency if it doesn't affect all of the speakers on that channel. We're 2ch people so tuning needs be done in 2ch to be balanced. If you turn down let's say 500hz that will affect harmonic structure of the magnitude all the way up and down the spectrum. Haven't you ever turned up or down 20khz? Ever notice it will affect the other frequencies like 10khz and 5khz (I think it effects all the frequencies go but I'll use harmonics to make the point) if you change the harmonic structure of the signal only on part of the signal the harmonics won't be in sync so to speak. So any eq I make to a single speaker I apply it to fix crossover slopes. So when measuring for abnormalities in crossovers I want to eliminate the roomout of my measurements so it more faithfully represents the electrical signal. right in front of the speaker will dictate the speakers closest resemblance to the electrical signal so that's where you want to make measurements for making acoustic and electrical signals match for crossover slopes. If I want a linear crossover I need the crossover acoustic behavior to match the linear slope that is electric so that way it's doing what it says and not something else.

So stop band is everywhere below/above the crossover point. When I make these close measurements I want to flatten the areas below/above my crossover points. Except I will have the crossovers off for this. Now the common sence. If the close measurement isn't manageable within a few db of cut boost on it I won't radically alter the signal. It's like we just want a bit of smoothing so the response is more flat. As long as it sounds good it will work. Meaning again I wouldn't go boost a frequency 10db or something absurd. If the speakers close responce isn't already close to flat I fix the problem to make it more flat . At crossover and the first oactave I try to make pretty flat. Remember this will bean area that will be attenuated , so the louder levels will be heard more so its more important closer up the slope and less important down slope. Depending on how shallow your slope is would also bag for some common sense on how much to use . You just want the responce to be somewhat flat so when you do engage the crossover it will do what you see on your dsp screen and not something else like have a big peak half oactave into the crossover. 

Once crossovers are measured and linearized than I apply gloabal eq to actually flatten the frequency response at the listening position. 

So why is it okay to add eq at a specific speaker at crossover and not anywhere else? Because that will be an attenuated spot in the spectrum the summed signals from the Speakers overlap areas will be "in tune" first. Then it's time to address the room and the system as a whole . There are some people who are dead set against anything but global EQ . Saying there's no need for it if your crossovers are good and placement is good, and I am onboard with that a single 30band eq on a system an offense more deadly than the most exotic processor in the wrong hands. And I think that that sentiment is valid, to keep the fidelity of the original signal. Only because environmental issues are so complicated to deal with . That's why I am really interested in Dirac and apl. It's a approach that effects the entire signal at once. It does it just fix phase per speaker he just fixes the phase of the entire signal which would be better on a more grand scale two include timing/phase moreover FR.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I don't know how important any of that is with Dirac or apl . In fact it seems like it would just fix all that stuff along the way so that might be something to consider.

Obviously the less processing the better, I have to work with these first before I can speak to there ability, so that whole thing might be redundant:/


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## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> To take what I said and add some common sense in your own way and your own system. Your gain structure will be different than another and you will know how your amps and equipment like to be gained. So use good judgment and steer clear of large amounts of boost when there's already a strong signal going in/out. There's barely any digital headroom, in most recordings post y2k.
> 
> So in general when tuning your system for good balance there is a way with all the various in/out eqs.
> 
> My method works in my system and makes sense acoustically for my system and previous renditions on how I like things to sound. 1st off I under gain my amps. I think it sounds better and I like all analog signals going in to be there max without clipping. *Just how I roll.


Sure, and the gain structure is definitely one of my weak points. I never really bothered to study more this.
Or I think I always under-used my amps in a way. Less gain than optimal probably.
And I kind of used them to simplify my work later on the dsp (to keep all at the same level or close enough), meaning limiting one channel to the highest one.
If it makes sense.
But I know I should, one day I;'ll come back around that.
Also I'm sure I don't listen as loud as many (you probably ) so with stronger amps I was ok so far.





oabeieo said:


> But as far as what I meant , if you have let's say a cdsp and you have input eq and output eq.
> 
> If your tuning the system as a whole you don't want to turn down any frequency if it doesn't affect all of the speakers on that channel. We're 2ch people so tuning needs be done in 2ch to be balanced. If you turn down let's say 500hz that will affect harmonic structure of the magnitude all the way up and down the spectrum. *Haven't you ever turned up or down 20khz? Ever notice it will affect the other frequencies like 10khz and 5khz (I think it effects all the frequencies go but I'll use harmonics to make the point) if you change the harmonic structure of the signal only on part of the signal the harmonics won't be in sync so to speak. So any eq I make to a single speaker I apply it to fix crossover slopes. So when measuring for abnormalities in crossovers I want to eliminate the room out of my measurements so it more faithfully represents the electrical signal. right in front of the speaker will dictate the speakers closest resemblance to the electrical signal so that's where*you want to make measurements for making acoustic and electrical signals match for crossover slopes. *If I want a linear crossover I need the crossover acoustic behavior to match the linear slope that is electric so that way it's doing what it says and not something else.


Ok. I totally see the points about harmonics, I keep too some frequencies quite high just because of that. Like I can't hear anymore over 17/18K alone but sure I hear the difference when they're cut in a track. Same for the sub, in the other way I think.
But about the acoustic slope, isn't it counter intuitive to apply some acoustic reference that don't come from the listening point ?
I mean "acoustic slope" should mean the slope that we hear no?
But I see the global point





oabeieo said:


> So stop band is everywhere below/above the crossover point. When I make these close measurements I want to flatten the areas below/above my crossover points. Except I will have the crossovers off for this. Now the common sense. If the close measurement isn't manageable within a few db of cut boost on it I won't radically alter the signal. It's like we just want a bit of smoothing so the response is more flat. As long as it sounds good it will work. Meaning again I wouldn't go boost a frequency 10db or something absurd. If the speakers close response isn't already close to flat I fix the problem to make it more flat . At crossover and the first octave I try to make pretty flat. Remember this will bean area that will be attenuated , *so the louder *levels will be heard more so its more important closer up the slope and less important down slope. *Depending on how shallow your slope is *would also bag for some common sense on how much to use . You just want the response to be somewhat flat so when you do engage the crossover it will do what you see on your dsp screen and not something else like have a big peak half oatcave into the crossover.
> 
> Once crossovers are measured and linearized than I apply global eq to actually flatten the *frequency response *at the listening position.
> 
> So why is it okay to add eq at a specific speaker at crossover and not anywhere else? **Because that will be an attenuated spot in the spectrum the summed signals *from the Speakers overlap areas will be "in tune" first. *Then it's time to address the room and the system as a whole . *There are some people who are dead set against anything but global EQ . Saying there's no need for it if your crossovers are good and placement is good, and I am onboard with that a single 30band eq on a system an offense more deadly than the most exotic processor in the wrong hands. *And I think that that sentiment is valid, *to keep the fidelity of the original signal. *Only because environmental issues are so complicated to deal with . *That's why I am really interested in Dirac and apl. It's a approach that effects the entire signal at once. *It does it just fix phase per speaker he just fixes the phase of the entire signal which would be better on a more grand scale two include timing/phase*more over FR.



Yeah here I follow you. Room correct the global response and not abnormalities coming from one driver that is off somewhere.
But it's a grey area too.


Ok so, well and thanx for your time here.
Just to get more synthetic (more as a recap for me here), I'll try to summarize both ways.
Let's remove the measurement methods out of the equation first, or just consider all as near-field, and call it A.
We could consider these two processes as:
- A1 = measure each driver w/1 sweep near field, eq to flat, then apply xo
- B1 = set xo, measure each driver w/1 sweep near field, then apply eq to dedicated target
In this case we shouldn't have any difference right? Maybe here and there but more depending of the choice on what to EQ or not. But the sum of all filters should have very close results, so A1=A2.

Now let's include the two different measurements methods, near-field VS listening position, in B:
- A2 = measure each driver w/1 sweep near field, eq to flat, then apply xo. So A2 = A1
- B2 = set xo, measure N sweeps each driver at listening position, then apply eq to dedicated target.
B2 is much harder to EQ since it's all over the places now, B1≠B2

Then let's add room correction (or what we tried to do in B2):
- A3 = A1 + measure large SPFR in cabin, then apply filters
- B3 = B2 + measure large SPFR in cabin, then apply filters
In A3 the filters are only based on the room effects, and dedicated to the volume measured (1-4 seats for example).
Same in B3, but we tried to fix some of the room effects already in B2, so we might get a cascade of EQ .
Can be ok, can be bad if wrong decisions were made in B2 (like ending with big boosts).
And filters are tied to the position selected in B2.

Just on feelings I think A is better. Each set of filter focuses on its thing, either flat to target or room correction. At least it seems a better baseline.
I just want to try that.
Because everything I tried until now (with ms8, apl etc) did work, was certainly listenable, but almost always brought some artefacts that I didn't want.
But I’m curious to have others feedback... Jazzi?

And also I should consider some kind of room treatments here, like fiberglass panels near the center console, under the dash etc.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Sure, and the gain structure is definitely one of my weak points. I never really bothered to study more this.
> Or I think I always under-used my amps in a way. Less gain than optimal probably.
> And I kind of used them to simplify my work later on the dsp (to keep all at the same level or close enough), meaning limiting one channel to the highest one.
> If it makes sense.
> But I know I should, one day I;'ll come back around that.
> Also I'm sure I don't listen as loud as many (you probably ) so with stronger amps I was ok so far.
> 
> 
> 
> 
> 
> Ok. I totally see the points about harmonics, I keep too some frequencies quite high just because of that. Like I can't hear anymore over 17/18K alone but sure I hear the difference when they're cut in a track. Same for the sub, in the other way I think.
> But about the acoustic slope, isn't it counter intuitive to apply some acoustic reference that don't come from the listening point ?
> I mean "acoustic slope" should mean the slope that we hear no?
> But I see the global point
> 
> 
> 
> 
> 
> 
> Yeah here I follow you. Room correct the global response and not abnormalities coming from one driver that is off somewhere.
> But it's a grey area too.
> 
> 
> Ok so, well and thanx for your time here.
> Just to get more synthetic (more as a recap for me here), I'll try to summarize both ways.
> Let's remove the measurement methods out of the equation first, or just consider all as near-field, and call it A.
> We could consider these two processes as:
> - A1 = measure each driver w/1 sweep near field, eq to flat, then apply xo
> - B1 = set xo, measure each driver w/1 sweep near field, then apply eq to dedicated target
> In this case we shouldn't have any difference right? Maybe here and there but more depending of the choice on what to EQ or not. But the sum of all filters should have very close results, so A1=A2.
> 
> Now let's include the two different measurements methods, near-field VS listening position, in B:
> - A2 = measure each driver w/1 sweep near field, eq to flat, then apply xo. So A2 = A1
> - B2 = set xo, measure N sweeps each driver at listening position, then apply eq to dedicated target.
> B2 is much harder to EQ since it's all over the places now, B1≠B2
> 
> Then let's add room correction (or what we tried to do in B2):
> - A3 = A1 + measure large SPFR in cabin, then apply filters
> - B3 = B2 + measure large SPFR in cabin, then apply filters
> In A3 the filters are only based on the room effects, and dedicated to the volume measured (1-4 seats for example).
> Same in B3, but we tried to fix some of the room effects already in B2, so we might get a cascade of EQ .
> Can be ok, can be bad if wrong decisions were made in B2 (like ending with big boosts).
> And filters are tied to the position selected in B2.
> 
> Just on feelings I think A is better. Each set of filter focuses on its thing, either flat to target or room correction. At least it seems a better baseline.
> I just want to try that.
> Because everything I tried until now (with ms8, apl etc) did work, was certainly listenable, but almost always brought some artefacts that I didn't want.
> But I’m curious to have others feedback... Jazzi?
> 
> And also I should consider some kind of room treatments here, like fiberglass panels near the center console, under the dash etc.




Okay these scenarios hurt my brain.

Yes a1 and a2 have similar outcomes , but I would add "eqflat" meaning just the stop band not the pass band , the pass band will be used with gloabal eq. 

A1 and a2 are similar ways to do it. except a1 (my method) makes it so you don't have to try to count down a imaginary slope on a RTA screen that is hard to do. And A1 can be done real time with RTA , so could A2 but againone crossover is engaged you'll have to draw an imaginary line to follow . Unless your RTA has filter targets  

Either way is acceptable, yeah we just want the acoustic slope to match the electrical, my way sounds better to me , I can't explain why and I've done both. 
Maybe someone else can .
Anyway you said b2 is harder because all over the place....not if your using separate eqs and that's the point. Input eq for global eq output/channel eq for speaker related issues and those are small adjustment that barely make a difference but a difference that can mean a lot 


I tryed Dirac . Got the free download , it works , I'll post in my build page to not thread hijack .


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> Okay these scenarios hurt my brain.
> 
> Yes a1 and a2 have similar outcomes , but I would add "eqflat" meaning just the stop band not the pass band , the pass band will be used with gloabal eq.
> 
> A1 and a2 are similar ways to do it. except a1 (my method) makes it so you don't have to try to count down a imaginary slope on a RTA screen that is hard to do. And A1 can be done real time with RTA , so could A2 but againone crossover is engaged you'll have to draw an imaginary line to follow . Unless your RTA has filter targets
> 
> Either way is acceptable, yeah we just want the acoustic slope to match the electrical, my way sounds better to me , I can't explain why and I've done both.
> Maybe someone else can .
> Anyway you said b2 is harder because all over the place....not if your using separate eqs and that's the point. Input eq for global eq output/channel eq for speaker related issues and those are small adjustment that barely make a difference but a difference that can mean a lot
> 
> 
> I tryed Dirac . Got the free download , it works , I'll post in my build page to not thread hijack .


Yeah those scenarios were more for me to build the idea. I need to think like that.
Ok I forgot the stop band only, it would work with both, with same effects, and I tried that with good results. 

Don't forget jazzi's spreadsheets for the crossover targets, really handy to see the XO curve to reach.
Especially used with auto EQ, really powerful!

I said B2 harder, but only on driver Eq, because you tune the average in this case, and it can be real crazy. Especially with spfr method.
But yeah I never really used input eq before (always had the apl too for this).
Or barely to finetune L/R, and if I went out of peqs per driver. But I see that in your method it should not be used for one driver.
Another use was to quickly try different targets too while driving.

But bigger point I didn't realized: you use RTA. I use sweeps only.
Rta kind of includes some effect from the room already.
That will push the tuning into the grey zone, mix of both methods.

Grey zone that I was talking about, that each method use some bits of the other one too in a way.
don't know why but I didn't like the results with rta. Like if too many dips and peaks were masked.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Yeah those scenarios were more for me to build the idea. I need to think like that.
> Ok I forgot the stop band only, it would work with both, with same effects, and I tried that with good results.
> 
> Don't forget jazzi's spreadsheets for the crossover targets, really handy to see the XO curve to reach.
> Especially used with auto EQ, really powerful!
> 
> I said B2 harder, but only on driver Eq, because you tune the average in this case, and it can be real crazy. Especially with spfr method.
> But yeah I never really used input eq before (always had the apl too for this).
> Or barely to finetune L/R, and if I went out of peqs per driver. But I see that in your method it should not be used for one driver.
> Another use was to quickly try different targets too while driving.
> 
> But bigger point I didn't realized: you use RTA. I use sweeps only.
> Rta kind of includes some effect from the room already.
> That will push the tuning into the grey zone, mix of both methods.
> 
> Grey zone that I was talking about, that each method use some bits of the other one too in a way.
> don't know why but I didn't like the results with rta. Like if too many dips and peaks were masked.



Actually jazzi spreadsheet got me on this whole new way (for me) and some reading on diy


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Do you have TA? The untreated response curve suggests, that the sub and the mid bass may be out of phase and hence your dip from ~80-160, two octaves around your Sub to mid xover of 120. Also that the sub and mids may be on shallow slopes. I'd look at the timing and then lower the sub to mid xover to about 60hz.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Maybe I am wrong, but the idea of apl-method was to separate results measured at near field from other reflections, which will be anyway separated by our brains due to longer arrival time. This idea seems to be hidden in the calculation algorythm.

Sendt fra min T1-A21L med Tapatalk


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yeah , I agree ^ 
It's almost like you can turn crossovers on for safety and separation and almost ignore everything else and just let it do its thing. 

You would get a stronger signal as well being your not duplicating any eq or letting apl undo any eq you did cause it can do it a different way


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Maybe I am wrong, but the idea of apl-method was to separate results measured at near field from other reflections, which will be anyway separated by our brains due to longer arrival time. This idea seems to be hidden in the calculation algorythm.
> 
> Sendt fra min T1-A21L med Tapatalk


Hey Alex, long time.
Not sure I understand, are you talking about the "on axis'' measurements as coreection with APL?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

No. Exclusion of interference from messurement results. It is nothing to do with on-axis test.

Sendt fra min GT-I9505 med Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am focusing now on application of the apl-technology on all my android devices. It sounds great without apl-hardware. Just measurements from the Workshop. This means a big step forward on the caraudio marked for android headunits. 

Sendt fra min GT-I9505 med Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Well, I finally have mine installed and so far it's totally frustrating.

Signal chain: iPhone --> HDMI Dongle --> HDMI audio de-embedder --> digital coax(2 channel) --> APL1 --> 800PRS

It's clipping the inputs of the 800PRS. I need to turn down the outputs somehow. The problem is, APL Config refuses to connect to it. I get a confirmation that the computer sees it when I plug in the cable, but the software just won't connect.

It's running on a MacBook Pro with the current on and Windows 10 running on the latest version of VMware Fusion.

Also, when I ran sweeps with APL Workshop it would get to about 170 sweeps, then start counting over again. No matter how many sweep I do, when I stop recording, I get an error that the file isn't long enough.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It might be a problem with the drivers under windows10. Rajmonds knows how to fix it. I am still using XP and never had issues with it. 

Sendt fra min GT-I9505 med Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Typically clipping is the result of no or little headroom. I have the same problem when trying to force small computet speakers to play the full range. At moderate volume it is ok. But if playing loud it sounds very bad due to clipping. Try to change the target curve in a first turn.

Sendt fra min GT-I9505 med Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Typically clipping is the result of no or little headroom. I have the same problem when trying to force small computet speakers to play the full range. At moderate volume it is ok. But if playing loud it sounds very bad due to clipping. Try to change the target curve in a first turn.


The clipping is there at all volume levels, so it's coming from before the headunit. Since the signal going into the APL1 is digital and the setup disables the volume control on my phone. That leaves the APL1 as the culprit. Unfortunately, since I can't get the software to connect to it, I can't adjust anything.



Alextaastrup said:


> It might be a problem with the drivers under windows10. Rajmonds knows how to fix it. I am still using XP and never had issues with it.


I took Raimonds advice and installed the software to a USB drive, so I'll dig up my older Windows 8 computer and see if I have any better luck.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I can't get the driver to install on my Windows 8 computer.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Can't help with w8, sorry. With regard to clipping: when I connect CD-changer to the apl1 through toslink, it plays very loud. Rajmond has suggested to reduce the level in correction files by -6dB. As soon as I got a switch with 15 pisitions for presets, I made kind of digital volume control. Using 6 presets ranging from -6 til -18 dB. That helped as otherwise no volume control was possible. Connecting using analog signal is another solution, just loosing some sound quality, but enhancing functionality.

Sendt fra min T1-A21L med Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

There has to be a correct procedure for setting gains through a system running an APL1 and a DSP. It would be helpful to post it.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It is an important thing. Let`s discuss it. Please give us more information about your setup!

Happy New Year to all sound enthusiasts!


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I can't get the driver to install on my Windows 8 computer.


Windows 8, Windows 10 64 bit versions do not allow (silently, no information) to install drivers that are not signed by Microsoft.
Such procedure must be followed to overcome that:
https://learn.sparkfun.com/tutorial...abling-signed-driver-enforcement-on-windows-8


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was able install the drivers on both computers, but Windows 10 still refuses to connect to the ALP1. However the Windows 8 computer connects now, I guess I know what computer I'll be tuning with, lol.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Isn't it possible to create image of w7 or w XP when running more advanced os? How this will influence application of the apl drivers? JUST ASKING...

Sendt fra min GT-I9505 med Tapatalk


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have no idea, I'm a Mac guy and only have two computers with Windows 8 and 10 on them to run some work software. I haven't had Windows on a computer I use daily since shortly after XP SP2 came out.


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## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Try holding the SHIFT key while right-clicking the APL1 application and select Open With Administartor (or similar, not in front of PC). This will give elevated privileges that might overcome the issue.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I got it!

I was able to run some sweeps and then poke around in Workshop and figure out the workflow. I had to look in the Quick Start guide a few times, but I think I've figured it out.

I ended up using Coneq PE1 to make a file that helped me some. I made two filters, one is an 80Hz High Pass Filter, I don't have subs right now and still have the factory speakers. The other filter is a High Shelf at 5hz that I initially set to -5db to keep the APL1 from clipping the inputs of the 800PRS. I eventually wound up setting it at -15db. I'll probably break out my O'Scope and do some testing with tones to find the right amount of cut. Being able to combine the two filters into one file is mighty handy.

Back in Workshop I built a project default that includes the Mic calibration file, the file from Coneq and the mp1 curve as my targets. I did 250 sweeps with each side playing, moving the mic around. It looks like if you setup the project default then Workshop automatically applies them when you are done recording, nifty.

I had music playing when I loaded the settings into the APL1 and it was fantastic when everything just snapped into focus. The highs were much quieter than I expected. I ran another round of sweeps, applied the changes and BAM! That put a HUGE smile on my face.

Now the car doesn't sound at all like it has factory speakers on very little power. It sounds like I've put a LOT more work into the stereo.

I am curious about something that I didn't think to test while I was in the car. When I make a change to the file in Coneq, then save it over the one I'm updating, does Workshop automatically see those changes when I click "Calculate" in the lower right corner of the main window? Or do I have to manually reload the file?

I'll take some screenshots and see if I can'y put a click-cy-click walk through together to see if I'm missing anything and to help others out.

Based on my experience today, it was totally worth the effort to figure this out!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Glad to hear about your achievements. It is really not a simple task to work with apl/workshop, but the results worth doing this. It is, by the way, suggested to make at least 3 consequent measurements with sweeps on every side with averaging afterwords. I did it so, but my experience shows a very good repeatibility of the test results. If you have at least 15 dB between a signal and noise level, then the curves measured are always almost identical. So there is no need to repeat process of sweeping with a microfon if your first test consistedof 250 points. Typically I stop at 130-150 measuring points.

Sendt fra min T1-A21L med Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Glad to hear about your achievements. It is really not a simple task to work with apl/workshop, but the results worth doing this. It is, by the way, suggested to make at least 3 consequent measurements with sweeps on every side with averaging afterwords. I did it so, but my experience shows a very good repeatibility of the test results. If you have at least 15 dB between a signal and noise level, then the curves measured are always almost identical. So there is no need to repeat process of sweeping with a microfon if your first test consistedof 250 points. Typically I stop at 130-150 measuring points.
> 
> Sendt fra min T1-A21L med Tapatalk


I still have a bunch to learn, I'll spend more time with it this week. I ran the sweep again to see what had changed. Now I realize that after running the sweeps and letting Workshop do it's thing, it wasn't adding to the changes made after the first sweeps, but was totally replacing that tune. 

I'm curious is there is a way to run sweeps, make some changes, run sweeps and build on the first set of changes instead of totally replacing them?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> It is an important thing. Let`s discuss it. Please give us more information about your setup!
> 
> Happy New Year to all sound enthusiasts!




My system includes the following:


mObridge DA1 preamp (optical out)
APL1 (optical in, optical out)
Helix DSP Pro (optical in, RCA analog out) Director control for master volume.
Sinfoni amplifiers


The mObridge has a variable volume control that works from the OEM volume knob on the Audi MMI. The volume range is from 0 to 34. The maximum undistorted volume level is 33.

I set my amplifier gains using -5dB and -10dB overlap tones and an oscilloscope. I did this with the mObridge volume at 33/34.

I use the Director on the Helix Pro to control my master volume.


When I added the APL1 and did the measurements and loaded the FIR file, my music was distorted due to the APL1 boosting signal. That means I need to reduce level on the input signal, but I don't know how far down I should turn it. Also, when I turn down the head unit volume I am worried I will have to adjust the gains on my amplifiers since they will probably be too low.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

*Things I Learned Today*

I think one of the more important things is that the whole process can generate a LOT of files, you need to plan for this. If you are the kida person that just kinda tosses files on the desktop all willynilly, then you are probably gonna make a mess. I installed all of my APL programs into a 16GB flash drive, so I decided to keep all the new files there, sorted by car. This is also helpful so I can pull up the data on my main laptop instead of just my older laptop with the crappy trackpad.

Since this APL1 was originally purchased for my Bronco and I put it in the Miata instead, I'll end up buying another one. If I didn't keep things in order from the sart, it could easily become a big mess!

But wait, there's more!


*Coneq PE1*
For starters, if you need to build in a crossover or do some PEQ work, Ceneq PE1 is mighty handy.










You can make all those changes and then save them to a single file that only takes up one target line in Workshop. In my case you can see the 80Hz HPF for the whole car on setting 1. Then you can see my workaround for output attenuation on setting 2. This gets saved as a single file to my car's data folder on the flash drive. It's just a text file that looks like this:










*APL Workshop*

Ok, this is the program that gave me to most trouble, It's really quite complex:












I think the first thing you should do is setup where all your files are going. So go into settings and you'll find this:










• The "Default projects folder" is where it'll save all the files.
• The "Filter file exchange folder" is where it'll save the files you upload into the APL1

You might also check to make sure that is says "4096" for "Filter length in samples" Mine didn't and I'l pretty sure the APL1 has 4096 taps.

I left all the other settings alone because I don't know what they do.

Now that you have that setup, close the window and create a new project. You'll get a window that looks like this, but the measurements window will be empty:










You can't really do much here until after you take a new measurement. but what you can do is get a few things ready that'll make things easier after you take your measurements.

In the upper right hand corner click "Edit project defaults" button and you get this screen:










I left everything under "Calculation parameters" alone. Go over to "Compensations, corrections, targets" you have seven lines where you can add things like your Mic/soundcard calibration files, target curves and so on. 

Put your Mic calibration file in there to start with. You can't enter anything until you check the box to activate that line. Click the box with the ellipsis to get the window to find your file. It might need to modify your file, when it does it'll create a new file for you. 

You can do the same with target curves, like the one I made in Coneq. I also added the mp1 target curve, it very closely resembles the Harmon curve Andy has posted several times but with a dip to help with that potentially annoying area around 3k. When you click the ellipsis box it should open up to the folder with the APL target curves.

You can click the "v" to see the curve on a graph if you'd like. Don't forget to tell it if the file you just picked is a compensation(mic cal) or target. I accidentally forget that and got errors later on.

And last, you can name each line to help keep everything in order. After that, go to the top and enter a name in the "Preset" box. Then click "Save as preset"

You are done here, close the window. Now it's time for the real fun, lets make a new measurement! On the left where you have the big empty "Measurements" window, click on "New" at the bottom of that window, you'll get this window:










Well, it won't be exactly like that, I took that screenshot while playing the sweeps. The blue level bar won't be doing anything, the "Play test signal" button won't be greyed out, but the other related buttons will be greyed out. 

If you setup some default filters for your project, then those will already be entered here. If you don't want to use them you can just uncheck them. You can also add more if you want. But don't fear, you can add them after running your sweeps later if you need.

Start by giving your sweep a name, at the top of the screen. Plug your computer into your car and and make sure the sound output drop down box is set to the correct output. Also, just to the right, make sure you are testing the correct channel, left or right. Next plug in your mic and make sure it is selected in the next drop down box.

Let's make some noise!

Click "Play test signal" you should hear the sweeps on your stereo now. If not, it's time to troubleshoot. If you are hearing the sweeps, keep an eye on the blue bar while adjusting the volume. 

It isn't collecting data yet, so once you are ready, click "Record". The box just to the left of record will stat counting how many sweeps you've recorded. This is the part where you look like an idiot to anyone who doesn't know whats going on. Move your mic around to cover the listening area. Once you feel you've covered enough area, click "Stop".

There will be a blue progress bar at the bottom of the screen, once it is done crunching the data you will get a graph with your results. If you had setup a preset before doing this, then that will be be figured out as well. When you close the graph you'll return to this screen:










If you used a preset then those setting will be listed. You can deactivate something if you want, or add more. If you make any changes here, the click "Calculate" in the lower right corner and you'll get the blue progress bar again and get another graph. You will also get a new item listed under that measurement name on the left. You can right click and add comments to rename them.

I haven't been able to click on the "Parametric EQ" or "Phase correction" yet. Anyone have info about that?

If you want to upload your corrections to your APL1 then just right click on that item in the "Measurements" box, you can send it to Channel 1 or 2. This doesn't actually load it on to the APL1, it just saves a file in the "Exchange" folder you setup in picture number 4 of this post.

*APL Config*

Now go open your APL Config program, you'll be greeted with this window:









Plug your USB cable into the APL1 and click connect. If your drivers installed correctly, then it should connect right away and tell you in the white box on the lower left of the screen. If you want, you can download the original config files and save them away. When you are ready to upload your tune, click the ellipsis next to that channel and find the file, it'll be in your "Exchange" folder. Do the same for the other channel, then click "Write To Device"

If you are playing music while this is happening, then in a couple second you'll hear it change. If it's your first tune then things might change drastically! 

*Final Thoughts*

First, if anyone has read this whole thread, then it's no secret that I'm not an experienced user of this device and software. However, it's also no secret that a handful of us have been waiting for a detailed post like this. If any of the more experienced APL users, or Raimonds himself, has suggestions, corrections or recommendations, then please quote *JUST* the section that needs to be changed. I don't think quoting this whole long ass post will be too helpful. 

So, it took a long time of screwing around to finally get my APL1 installed, and during that long wait I fired up the software many times and tried to see if I could figure it out. The software isn't nearly as intuitive as FIR Designer, but after hearing the dramatic change it made to my system, it was worth the trouble.

The signal chain in my Miata is this: iPhone --> APL1 --> DEH-P800PRS --> Stock speakers, no amps. There are more details in a previous post in this thread, or in my build thread.

For fun, here are a couple graphs from today:

Impulse responce before tuning:









After the first round:









Frequency response before tuning:









Frequency response after first tune:









These graphs don't tell the whole story though. The clarity, impact and focus of this really mundane system was GREATLY improved. It's a night and day difference. The other thing that surprised me, was once I figured out the presets, the time it took from taking a measurement to listening to it was incredibly short. This is SO much faster than running REW then copying any pasting BiQuads over, or manually entering settings.

I'm thinking I should temporarily install my preset switch so I can A-B it for people. There are two ports that the switch can plug in to, what is the correct port?

I plan to start over with the tune and include measurements from APL TDA(I bought ALL then APL software when I bought the hardware) so I can also see the impulse response over the whole spectrum as well. I also plan to do before and after measurements with REW. If things go well at work this week then I should be able to do all that this week. If not this week, then it'll be awhile, I have a bunch of traveling coming up.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> My system includes the following:
> 
> 
> mObridge DA1 preamp (optical out)
> APL1 (optical in, optical out)
> Helix DSP Pro (optical in, RCA analog out) Director control for master volume.
> Sinfoni amplifiers
> 
> 
> The mObridge has a variable volume control that works from the OEM volume knob on the Audi MMI. The volume range is from 0 to 34. The maximum undistorted volume level is 33.
> 
> I set my amplifier gains using -5dB and -10dB overlap tones and an oscilloscope. I did this with the mObridge volume at 33/34.
> 
> I use the Director on the Helix Pro to control my master volume.
> 
> 
> When I added the APL1 and did the measurements and loaded the FIR file, my music was distorted due to the APL1 boosting signal. That means I need to reduce level on the input signal, but I don't know how far down I should turn it. Also, when I turn down the head unit volume I am worried I will have to adjust the gains on my amplifiers since they will probably be too low.


What I first tried today, and it worked, was to open up Coneq PE1 and build a single high shelf filter at 5hz and set it to -5db and save the file. I then opened the file in a text editor and changed the values that were above -5 to -5 and saved it. Then I used that file as a target curve. It's not slick, but it worked.

I eventually changed my method to what I listed in my previous post, but it does seem like there should be a better way. I lowered the output in 5db steps until the distortion was gone. I'll try again with 0db test tones and my scope soon.

Someone earlier in this thread posted about connecting with Ceneq C1:










It has nifty slider just for this purpose, and would be the fastest way to set your gains, but I can't get this software to see the APL1.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> My system includes the following:
> 
> 
> mObridge DA1 preamp (optical out)
> APL1 (optical in, optical out)
> Helix DSP Pro (optical in, RCA analog out) Director control for master volume.
> Sinfoni amplifiers
> 
> 
> The mObridge has a variable volume control that works from the OEM volume knob on the Audi MMI. The volume range is from 0 to 34. The maximum undistorted volume level is 33.
> 
> I set my amplifier gains using -5dB and -10dB overlap tones and an oscilloscope. I did this with the mObridge volume at 33/34.
> 
> I use the Director on the Helix Pro to control my master volume.
> 
> 
> When I added the APL1 and did the measurements and loaded the FIR file, my music was distorted due to the APL1 boosting signal. That means I need to reduce level on the input signal, but I don't know how far down I should turn it. Also, when I turn down the head unit volume I am worried I will have to adjust the gains on my amplifiers since they will probably be too low.


There is only one place to thing about gains - amplifier`s gains.
They should be set to max at first step.
If the use of max gains do not disturb you with a noise - it is nice.
If you hear little bit too much noise, please reduce amplifier`s gain
such way, that you still hear a noise but it does not disturb you.

Than play some music starting with low volume on mObridge.
Than increase volume to find where amplifiers hit a clip.
Amplifiers must hit a clip when volume control is on some medium position.
If it is to low (system has too much gain) than reduce amplifier`s gain
by amount that is equal to amount by which you like to increase position of volume control.

If you have a multi way system you should forget to use the volume control in max position.
The max usable position of volume control (distortion free) depends on a weakest band in your system
and how the particular music track has been made.

By setting amplifier`s gains to max usable, you are adding a headroom for your signal path.
You can not use any system with DSP without sufficient signal processing headroom.
As much higher it is(as high gains on amplifiers) as better for you.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks to LumbermanSVO for nice results and understanding!

Here is some points why you should spent your time to learn how to work with APL tools



LumbermanSVO said:


> .....
> I had music playing when I loaded the settings into the APL1 and it was fantastic when everything just snapped into focus. The highs were much quieter than I expected. I ran another round of sweeps, applied the changes and BAM! That put a HUGE smile on my face.
> 
> Now the car doesn't sound at all like it has factory speakers on very little power. It sounds like I've put a LOT more work into the stereo.
> .....





LumbermanSVO said:


> *
> .....
> So, it took a long time of screwing around to finally get my APL1 installed, and during that long wait I fired up the software many times and tried to see if I could figure it out. The software isn't nearly as intuitive as FIR Designer, but after hearing the dramatic change it made to my system, it was worth the trouble.
> 
> .....
> These graphs don't tell the whole story though. The clarity, impact and focus of this really mundane system was GREATLY improved. It's a night and day difference. The other thing that surprised me, was once I figured out the presets, the time it took from taking a measurement to listening to it was incredibly short. This is SO much faster than running REW then copying any pasting BiQuads over, or manually entering settings.
> .....
> I'm thinking I should temporarily install my preset switch so I can A-B it for people. There are two ports that the switch can plug in to, what is the correct port?
> .....
> *


*
The correct port is next to USB connector.

APL tools were created as tools for professionals. 
The use of them is requesting professional attitude.
It is impossible to have just one "RUN" button.

The goal of development of APL tools was to make possible nice tuning results
and that is not possible by use of just one button.

Yes, it is possible to hear result incredible fast. 1) make your measurement (make a "sweep") 2) take a look on curves to be sure that 

everything is ok 3) right click on respective measurement(recalculation) for left channel and chose "send to 1st channel" and 

same way for right channel 4) press ctrl+F5 to send filters to APL1 unit (the APL Configuration software must be running, have 

connection with APL1 unit and have been correctly reconfigured)

Sorry, it is tricky to use C1 tool in filter file path to APL1 unit.
The way to use it is described in Quick Start Guide.
In short words: 3 softwares must be reconfigured to use the same exchange folder ( must be a root of some disk to use for C1)
WORKSHOP - by use of "Filter file exchange folder"
APL Configuration - by use of "Settings/Fast Reload/Source directory"
C1 - by copy of the "!apeq_id.txt" file into respective folder, a root of some disk, c:/ for example*


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In my system, there are 2 points where I can control volume. The head unit volume controls the digital level from the mObridge DA1. Then I have the Director which controls the analog out from the DSP.

I want to use only the Director for master volume.

Where should I set the mObridge volume?


I am currently starting a new system in a different car. The new system has a Sony RSX-GS9 head unit as the source.

The Sony has an optical output but no volume control. The optical output only plays at 0 dB Fs. If I add APL1 to this car, what should I do? You have said 0 dB Fs is not good, but some head units only output to 0 dB Fs with no option to control the level.


Sent from my iPhone using Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If APPLY button in rje Coneq PE1 is grey (not active) - it is an indication that paths are not set corectly and the programs arw not able to see each other.

Pay attention also to the horisontal sliders in the Coneq C1. They could be used for time delay alignment - very precisely. If you combine this with the TA settings in ordinary DSP, so you are on the right way.

Sendt fra min GT-I9505 med Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> The correct port is next to USB connector.


Thanks!



Raimonds said:


> Sorry, it is tricky to use C1 tool in filter file path to APL1 unit.
> The way to use it is described in Quick Start Guide.
> In short words: 3 softwares must be reconfigured to use the same exchange folder ( must be a root of some disk to use for C1)
> WORKSHOP - by use of "Filter file exchange folder"
> APL Configuration - by use of "Settings/Fast Reload/Source directory"
> C1 - by copy of the "!apeq_id.txt" file into respective folder, a root of some disk, c:/ for example





Alextaastrup said:


> If APPLY button in rje Coneq PE1 is grey (not active) - it is an indication that paths are not set corectly and the programs arw not able to see each other.
> 
> Pay attention also to the horisontal sliders in the Coneq C1. They could be used for time delay alignment - very precisely. If you combine this with the TA settings in ordinary DSP, so you are on the right way.



I'll take another shot at setting up C1 this afternoon, thanks!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

A couple days ago I had done a little bit of tuning with REW and just the 16 band of EQ on the 800PRS. This is what left side looked like in APL when I measured it yesterday:










There was nothing I could do with those big problems and just the 800PRS.

Yesterday I was able to get it sounding great, but it took a few rounds with APL. Today I started over, but with everything on the 800PRS set to flat for the first measurement, including the crossover. This is the baseline, no tune:










After that sweep I just exported the corrected file from Workshop, used Coneq C1 to attenuate it, then uploaded it to the APL1. I also set the HPF on the 800PRS to 80Hz @12db. This is the result:










And the right side looks even better:










This thing is brilliant! Even with the DEQ.8 that I had in the Bronco and REW, I couldn't have made such a smooth curve. It took a little over a minute to run the sweeps for each side, then less than a minute for Workshop to process. Another minute or so to export it, attenuate the file and then upload it to the APL1. Between both sides and swapping USB cables, this is literally an under 10 minute tune!

I could now easily open up Coneq PE1 and clean up the area between 400 and 2k on the left side, but at the moment I'm just going to enjoy it, it sounds great! Now I can't wait to get my new speakers and install the amp! 

I need to install the software so I can run TDA on the Windows 8 computer, while I'm at it I'll install REW, then do some sweeps with each. While I'm not a fan of the Windows 8 computer, the APL software seems to run better on an actual hardware install of Windows than a virtual install. Plus, that computer is MUCH smaller and fits in this tiny car much better!

While I was at it today, I also setup up my O-scope. I couldn't get the analog outputs of the APL1 to clip with no tune and 0db tones. However, I could easily get it to clip the inputs of the 800PRS. With Coneq C1 and a flat tune I was able to get the clipping to stop at -6db. After tuning I still had some audible clipping even at -6, but you can easily make multiple passes through Coneq C1 and I wound up back at -15db. However, unlike yesterday where I had to build the attenuation into the target tune with a goofy high shelf filter workaround, it was super simple to do after dropping the files into the exchange folder.

I couldn't find the !apeq_id.txt file anywhere on my flash drive, so I just reinstalled Coneq C1 and was able to find it right away. Once I dropped that file into the root directory of the flash drive, then set it as the exchange folder in the other software, then they all started working together.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Lumberman - First, thanks so much for the info and instructions.

Second, what are you using Coneq P1 for? You mention using it for crossovers but those are being handled by your DSP. Is it just to give the APL1 a little extra help in identifying where the crossover points are? I sort of understand using the Coneq P1 to attenuate the signal but then you mention running it through multiple times to get enough attenuation. It just seems that the Coneq steps add unnecessary complexity and I was wondering if there was a way to bypass it completely, especially since I think this is the first time I've really read that it was NEEDED over and above the APL Workshop. 

Thanks again. Great info!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> Lumberman - First, thanks so much for the info and instructions.


You're welcome. I work with pro-grade gear for a living and very few pieces of equipment actually come with a useful user's manual, you've be surprised how many manuals I've made over the last couple years. Whenever I figure out how to use a new software/hardware combo I make up a step-by-step manual and upload it to my company's server so our other techs can reference it. It REALLY cuts down on the late night panic calls.  So it wasn't too hard to bang that out. I'll work on an actual document and update it as my workflow changes and post it here when I've settled on a solid workflow.



dgage said:


> Second, what are you using Coneq P1 for? You mention using it for crossovers but those are being handled by your DSP. Is it just to give the APL1 a little extra help in identifying where the crossover points are? I sort of understand using the Coneq P1 to attenuate the signal but then you mention running it through multiple times to get enough attenuation. It just seems that the Coneq steps add unnecessary complexity and I was wondering if there was a way to bypass it completely, especially since I think this is the first time I've really read that it was NEEDED over and above the APL Workshop.


Right off the bat I had the same problem that I think subterFUSE is having. With my phone plugged into the analog inputs the setup worked wonderfully. However, with my phone going digital into the APL1, I got horrible clipping on most songs. It was clipping the inputs on my 800PRS. subterFUSE is getting this same clipping, but I believe he is going digital out of the the APL1 and into his "regular" processor. If you don;t have this problem, then yes, you could go on with life as if C1 didn't exist. 

After exporting to the file exchange folder I could open the file with Coneq C1, this little tool allows you to do a few things:










First of all, it appears that to Workshop, C1 and PE1 the file exchange folder is a "live" folder, and any changes made from any of these programs will erase the previous file and replace it with your updated one. In C1 you can backup the file you get from Workshop. Handy!

When you open C1 it'll load whatever two files you have in the exchange folder. If you adjust the level to -6db, it'll replace your current files with new ones that are attenuated by 6db, and the new file name will reflect that. In my case, I uploaded that file to the APL1 and still got clipping. So I just reloaded the -6db in C1 and the level sliders returned to the top. I set them back to -6db, and it created new files, and it was smart enough to name them xxxx_-12db. I uploaded them to the APL1 and there was still just a hint of clipping, so I went for one more trip through C1, but this time with only -3db. I uploaded the new files and all my clipping was gone. 

I think subterFUSE might need to do something similar. Just treat the APL1 like a regular analog device when setting up the gain structure of his setup, even though it's digital. If I recall correctly, he has no issue when he sets the bypass switch to "Bypass"

I don't know why the digital input is so much hotter than analog(Rainmonds?), but the solution is really simple and even with my super slow, so-low-power-it-doesn't-even-have-a-fan, laptop it just took seconds for each trip through C1

I addition to being able to adjust level and delay, you can click "Param EQ" and it'll take you to Coneq PE1. Here you have 12 bands of fully parametric EQ. If you make changes, you can then click "Apply" and it'll send those changes to C1 and C1 will generate a new file that you can upload.










I you like the tune you can easily use C1(or your file browser) to backup the fir file you sent to the APL1. And as long as you didn't close PE1, you can go back to it and click "save" and then drop that file into Workshop as a target curve. I haven't checked to see how well that works yet.

Well, I kinda didn't do that yet, and kinda did yesterday. Before getting Workshop, C1, PE1 and Config to all work together, I used PE1 to make a high pass filter and a high shelf to attenuate the entire frequency response and saved a file. I went for a long-ish drive today and found that the high pass wasn't quite up to snuff, (I don't have subs yet) so I wound up turning on the crossover on the 800PRS again. 

Today when starting over on the tune I removed the crossover and high shelf from Workshop and bypassed the crossover on the 800PRS. After taking the initial measurements I turned the crossover on the 800PRs back on.

As far as unnecessary steps go, with REW and my PPI DEQ.8 I'd spend 10 minutes just copy and pasting BiQuads. That's not counting the time it took to do sweeps. then hop into the EQ pane and get all that working well. Today I started from scratch and got that tune in 10 minutes. Yeah, I had to run the file through C1 three times, but it was still less time than I'd normally spend in REW.

Also, I think my neighbors think I'm crazy after watching me wave a microphone around in my car. :surprised:


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks. I looked back at the image up top with your "crossover" settings and realize you set a high-pass crossover since you aren't running subs and also one to attenuate the signal. And then you updated your workflow to use C1 to attenuate. Very clear. Thank you.

I notice you bought all of the APL software packages but so far have only worked with APL Workshop. Have you used any of the others to understand just how much value/capability one of the other APL packages provides?

And yes, I've worked with multiple versions of MiniDSPs and yes, working with the biquads and automated EQ settings from REW provides its own form of pain.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> Thanks. I looked back at the image up top with your "crossover" settings and realize you set a high-pass crossover since you aren't running subs and also one to attenuate the signal. And then you updated your workflow to use C1 to attenuate. Very clear. Thank you.
> 
> I notice you bought all of the APL software packages but so far have only worked with APL Workshop. Have you used any of the others to understand just how much value/capability one of the other APL packages provides?
> 
> And yes, I've worked with multiple versions of MiniDSPs and yes, working with the biquads and automated EQ settings from REW provides its own form of pain.


I misspoke when stating that I had purchased all of the APL software, I did not purchase TDA EQ because 9 months ago when I bought everything TDA EQ wasn't working well in cars. I understand there has been some progress with using TDA EQ in cars though... 

I did purchase TDA and have used it to test in my Bronco before yanking the dash, and all the audio gear. It was incredibly helpful when setting delays on all of my drivers. It was quite amazing how much the stage came together from using just that one tool.

The Bronco ran(and will again) horns and many people have had issues getting the timing right with them over the years, especially when using a tape measure. However, being able to see and measure the required delay right on the screen turned setting the delays into a quick job, once I figured out how to interpret the data. Totally worth it, and much more intuitive than Workshop.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Perfect Lumberman. Thanks again for helping everyone!

I bought the APL1 from a DIYMA member but haven't bought the software yet.

Also, I'm into home theater and it looks like the APL software will help me out there too, which is of course a win/win.

By the way, I have a home theater subwoofer company - Deep Sea Sound (Deep Sea Sound). I'll be working on some speakers this spring so the APL software will be really nice.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I still don't get why there are 3 software packages - APL Workshop, APL TDA, and APL TDA EQ. I sort of understand the APL Workshop for working with the APL1. TDA vs TDA EQ - nope, nada.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was trying to figure out where I knew your name from! I have a pair of MkII 24's still sitting in their shipping crates. In my research on AVS(I have the same SN there) I read a bunch of your posts. I have been mulling over the idea of contacting you for a possible flatpack for my 24's(and more) if you still do custom enclosures. If you do, then shoot me a PM so we don't derail this thread


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'd be curious to hear the history of Raimonds developing the different programs and how they fit in the timeline of the hardware. 

If you haven't used TDA yet, I believe you can run the trial for 30 days. Once you see the 3D impulse response of your speakers, you'll have a much better understanding of what it does that Workshop can't. Also, it's is very easy to figure out!

From my understanding, TDA EQ was developed more for the touring sound guy, and didn't deal with small spaces well. However, Raimonds has been working on that. I haven't used it myself, but I am curious about it.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am trying to find a simple way to connect apl1 to my BMW setup.

At the moment, the head unit high level output is connected to the helix pp82dsp which is integrated dsp/amp. I understand that I can connect the high level signal to the apl1 inputs directly. But I would need some sort of converter to change the Apl1 rca output to high level. But I can't seem to find any such converter

Another way it to use a android device as a source with apl running? If I want TP control the songs from my idrive, does connecting a android device to the USB input on my idrive work? Or all controls will have to be via the android device then?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> In my system, there are 2 points where I can control volume. The head unit volume controls the digital level from the mObridge DA1. Then I have the Director which controls the analog out from the DSP.
> 
> I want to use only the Director for master volume.
> 
> Where should I set the mObridge volume?


The mObridge volume should be set to -10 ... -15 to create a headroom for a signal processing.
Than you should set +6 ... +12dB gain after crossover filters and before DACs if such is available.
This is because of fact all frequency spectrum energy has been divided into bands and each of them receives just part of full energy. About 1/4 for 4 way system.




subterFUSE said:


> I am currently starting a new system in a different car. The new system has a Sony RSX-GS9 head unit as the source.
> 
> The Sony has an optical output but no volume control. The optical output only plays at 0 dB Fs. If I add APL1 to this car, what should I do? You have said 0 dB Fs is not good, but some head units only output to 0 dB Fs with no option to control the level.
> 
> 
> Sent from my iPhone using Tapatalk


Yes this problem is coming from "loudness wars" and is causing "no headroom" problem.
The use of some attenuation in APL1`s fir filter gives as a workaround for this problem.
It is possible in two ways. 1) by use of C1 to quickly alternate a fir filter file.
2) by use of parameter "EQ zero level" in Workshop software. If you set it to -15 for example, you will have 15 dB attenuation in fir filter 
You must be ready to fact that BYPASS switch on APL1 unit will not work nicely in case of use of attenuation. The Bypass will sound much louder because it is not attenuated.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I am trying to find a simple way to connect apl1 to my BMW setup.
> 
> At the moment, the head unit high level output is connected to the helix pp82dsp which is integrated dsp/amp. I understand that I can connect the high level signal to the apl1 inputs directly. But I would need some sort of converter to change the Apl1 rca output to high level. But I can't seem to find any such converter
> 
> Another way it to use a android device as a source with apl running? If I want TP control the songs from my idrive, does connecting a android device to the USB input on my idrive work? Or all controls will have to be via the android device then?


Looks like helix pp82dsp has 4 high level inputs, 1 AUX input (should be normal level) 1 SPDIF digital input. Last two ones can be used for connection to APL1 unit`s output.
The Android device you can connect directly to AUX input of helix pp82dsp.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Looks like helix pp82dsp has 4 high level inputs, 1 AUX input (should be normal level) 1 SPDIF digital input. Last two ones can be used for connection to APL1 unit`s output.
> The Android device you can connect directly to AUX input of helix pp82dsp.


The Aux input unfortunately runs seperately a the high level inputs. I need the rears of the high level input as that is connected to my rear parking sensors sound. So i I have music playing on the aux, I will not hear my parking sensors sound. Thats why i am checking if it is possible to convert rca back to speaker level and to do so at a good enough quality level.

Can you explain more about the android device? i do not see it on your web site. 

I assume I need to purchase the apl workshop as well to measure the car response? Or does it come with the apl1?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just try to mesure with the help of TDA with and withour apl and you will be surprised ☺

Sendt fra min GT-I9505 med Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> The Aux input unfortunately runs seperately a the high level inputs. I need the rears of the high level input as that is connected to my rear parking sensors sound. So i I have music playing on the aux, I will not hear my parking sensors sound. Thats why i am checking if it is possible to convert rca back to speaker level and to do so at a good enough quality level.
> 
> Can you explain more about the android device? i do not see it on your web site.
> 
> I assume I need to purchase the apl workshop as well to measure the car response? Or does it come with the apl1?


And what about Optical SPDIF-Toslink input?
You should use an Android device of your choice - a phone, a mini PC, a head unit - to play your music (it probably will replace your idrive). Than it is possible to run the APL`s equalizer on such device as an app. Workshop software and APL1 unit are products that are creating a set but they are being sold separately. You should have Workshop to create EQ files for app on Android device.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> by use of parameter "EQ zero level" in Workshop software. If you set it to -15 for example, you will have 15 dB attenuation in fir filter


Somehow I didn't see that setting, usefull!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I took two measurements with TDA today, this is with the APL1 set to flat:










And with the tune I posted last night:










Some parts look better before, some look better after.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thank you for nice examples!
They are far field pictures when ambient sound field is dominating over direct sound. It is showing the real complexity of a car environment.
It can not be improved by any electronic (correction) means. 
This picture is changing dramatically from one to another mic position point.
It is possible to find a point with better direct - ambient sound ratio to use it to set the timing.
We can improve this picture only by right loudspeaker`s placement.
It is possible to get such picture even in a car:








You can see the serious timing error in LF caused by a blind tuning by use of a ruler ...


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

And following previous question.
Such TDA image may be in case when a wide band loudspeaker is used for all the way to 20 kHz. Such loudspeaker has very uneven directivity and strong side lobes. That lobes are are creating reflections that are stronger then direct sound.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It would be interesting to do a tune with Workshop with the top down and compare it with the top up tune. Even more interesting to see the TDA charts between the two. Unfortunately, I just shipped the laptop I do my testing with off to a show, and I leave to go work that show on Sunday. I have three shows in a row and won't be home to do any more tuning and testing until March. 

However, in March I'll have all my new speakers ready to install.


----------



## felix509

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> Can you explain more about the android device? i do not see it on your web site.


I am awaiting more information on this as well... 



Raimonds said:


> You should have Workshop to create EQ files for app on Android device.


So there is a stand alone android app that will accept the APL workshop file??


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



felix509 said:


> So there is a stand alone android app that will accept the APL workshop file??


Yes, the app emulates APL1 unit or APL EP1 VST plugin.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What Raimonds suggests is an app called Viper4android, which comprises an convolver capable to work with the 7files made from measurements carried out by the Workshop. 

So you do not need apl1 box in a car, if you have android based head unit or smartphone as a source.

Using smartphone, it is possible to listen music from in-built speaker, ear-phone or another device connected by bluetooth or usb cable. Starting from Lollipop, all android versions support USB audio out. In this case you can just use the latest version of Poweramp or USB recorder Pro from the Google Play.

It is possible to get correction files to every acoustic system you own. Really smart


Sendt fra min GT-I9505 med Tapatalk


----------



## felix509

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks for the reply... 

I have been working on getting BruteFIR to work with my gear, will APL Workshop files work with BruteFIR on a linux system?  SO far I have only seen PCM or WAV files used for the Brutefir filters.

I am still reading and learning BruteFIR, it is alot to learn at once...

If I am able to use one less piece of gear(APL1) and use the BruteFIR as convolver instead, that would be amazing..


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



felix509 said:


> Thanks for the reply...
> 
> I have been working on getting BruteFIR to work with my gear, will APL Workshop files work with BruteFIR on a linux system? SO far I have only seen PCM or WAV files used for the Brutefir filters.
> 
> I am still reading and learning BruteFIR, it is alot to learn at once...
> 
> If I am able to use one less piece of gear(APL1) and use the BruteFIR as convolver instead, that would be amazing..


Yes, it is possible to convert APL`s fir files to any third party fir filter file format on demand.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Dear Friends,

Some announcement.

Acoustic Power Lab (APL) has become SynAudCon sponsor! It is well-known training company among audio engineers and sound system professionals. SynAudCon offers practical and relevant education through their in-person seminars, online training, member’s forum, and their online educational library.
Celebrating this event we want to share our joy with our clients and we have fantastic gifts:
SynAudCom membership opens the door to a wealth of audio information and provides unlimited opportunity for connecting and collaborating with thousands of industry professionals. It also includes: member’s forum; over 500 technical articles on audio and acoustics; intensive field studies; RIR exchange; member directory. 
And the most valuable present is a chance to attend training course at SynAudCon. All the detailed information will be given individually. 
(Simply make an order for any of APL products and get your present! )
Please contact APL to get your free SynAudCom membership or to attend training course at SynAudCon. (Prospective customers will have preference.)
Notice: the present amount is limited!
Also, to support an education and in conjunction with this event, APL is offering APL TDA software’s individual license for student’s license price for one month.


----------



## oscardillo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is it possible to mount it in a system with passive filters? In this case the "apl1" will mount before the passive filter ?.

Finally they did not upload any videos

Greetings.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oscardillo said:


> Is it possible to mount it in a system with passive filters? In this case the "apl1" will mount before the passive filter ?.
> 
> Finally they did not upload any videos
> 
> Greetings.


Sure you can, it’s the typical use with regular speakers.
Although in car it’s maybe not the first thing to do, if your passive crossover is already great why not, it will work.
But you might gain more by switching first to full active and EQ.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have been using this solution with 3way front in almost two years. It was necessary as apl1 is limited to only two channels. Works great. Will keep this passive setup for a couple of years more.

Sendt fra min T1-A21L med Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oscardillo said:


> Is it possible to mount it in a system with passive filters? In this case the "apl1" will mount before the passive filter ?.
> 
> Finally they did not upload any videos
> 
> Greetings.


I have mine between my iPhone and head unit, works great!


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Yes, the app emulates APL1 unit or APL EP1 VST plugin.


What app?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am trying out the software without the actual unit. So far I have been converting my songs using the MP1 target. MP1 seems to emphasize bass more rather then strings which is my preference. So I am hoping for another target to shoot for. I believe the 2-3k dip does seem to make vocals feel a little lean and less warm. The lower bass also sometimes seem to sound a little heavy. As such, I was wondering if anyone else has decided on other target levels and why?



Also does going for say 300-400 points per measurement improve on the accuracy instead of the typical 150-200 for each side measurement painting? I am facing a issue where I seem to have a big dip at 1k and 5-7k region on both sides. But if I do a average RTA with pink noise, there is no big dip at that region around my head region. Changing my crossovers and slope which are nowhere near that area does not seem to impact or change that dip which APL workshop is saying exist. At the moment, I am measuring sitting in the driver position and painting starting from the wind screen from up to down and moving slowly back to just before the back of the front seats. No lower then the door windows and carefully avoiding the playing speakers by around 15-20cm.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I am trying out the software without the actual unit. So far I have been converting my songs using the MP1 target. MP1 seems to emphasize bass more rather then strings which is my preference. So I am hoping for another target to shoot for. I believe the 2-3k dip does seem to make vocals feel a little lean and less warm. The lower bass also sometimes seem to sound a little heavy. As such, I was wondering if anyone else has decided on other target levels and why?


It's really car/setup/driving/loudness dependant, and of course personal taste. Mp1 is perfect for my daily drive which is low speed. When I prefer flatter for listening session engine off, and more bass when driving faster.
I have an mp1 version with the dip "filled", but it can cause a bit of ear fatigue.
Well after multiple targets I usually go back to the regular mp1.




> Also does going for say 300-400 points per measurement improve on the accuracy instead of the typical 150-200 for each side measurement painting? I am facing a issue where I seem to have a big dip at 1k and 5-7k region on both sides. But if I do a average RTA with pink noise, there is no big dip at that region around my head region. Changing my crossovers and slope which are nowhere near that area does not seem to impact or change that dip which APL workshop is saying exist. At the moment, I am measuring sitting in the driver position and painting starting from the wind screen from up to down and moving slowly back to just before the back of the front seats. No lower then the door windows and carefully avoiding the playing speakers by around 15-20cm.


200 is good enough but of course more won't hurt. You should see if it adds anything on the curve. Less can also work fine, it's already kind of long to do.
For the painting method, same here it's car dependent, but I good results trying to catch the maximum volume. So lower than the door glass, from seat base to the roof, windshield to seats and side glass to side glass (real close). Except few problematic areas like the very corner of my windshield (accute angle with my prominent dash).
For your dips, how big are they? And are they pre or post APL?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> It's really car/setup/driving/loudness dependant, and of course personal taste. Mp1 is perfect for my daily drive which is low speed. When I prefer flatter for listening session engine off, and more bass when driving faster.
> I have an mp1 version with the dip "filled", but it can cause a bit of ear fatigue.
> Well after multiple targets I usually go back to the regular mp1.
> 
> 
> 
> 
> 200 is good enough but of course more won't hurt. You should see if it adds anything on the curve. Less can also work fine, it's already kind of long to do.
> For the painting method, same here it's car dependent, but I good results trying to catch the maximum volume. So lower than the door glass, from seat base to the roof, windshield to seats and side glass to side glass (real close). Except few problematic areas like the very corner of my windshield (accute angle with my prominent dash).
> For your dips, how big are they? And are they pre or post APL?



Thanks for your reply. I will listen to MP1 a little longer to see how I like it. For Home audio, I do like the 2-3k dip.

My 1k and 5-k dips are in the region of 10-15DB. They are pre APL. As I do not have the hardware, I am unable to measure post APL to see if APL filters did fix the problem. It does seem to indicate that it can bring up the 5-7k dip almost to the target level and half the 1k dip. Its just very strange that my crossovers are no where near there and does not seem to impact the dip even when I am changing the slope or type. It also happens on both sides almost equally. 

I be redoing some new measurements with another TA to see if I can get it better which should not be difficult I hope.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I think I found out why the measurement result looks so poor! I have been doing the paint measurement from the driver seat. I attached 2 files and you will know immediately which was "poor" result was from the driver seat and which was from the passenger seat. Both are from the Left speakers only. 

Which brings me to the question, why does it look so different? Please ignore the target curve which I had for the driver seat measurement but did not use for the passenger seat measurement.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You could upload the FIR filters and measure one more time in order to see how apl worked it out. This re-check is also important for further eq if necessary. You will know what to do and where. 

Sendt fra min GT-I9505 med Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I think I found out why the measurement result looks so poor! I have been doing the paint measurement from the driver seat. I attached 2 files and you will know immediately which was "poor" result was from the driver seat and which was from the passenger seat. Both are from the Left speakers only.
> 
> Which brings me to the question, why does it look so different? Please ignore the target curve which I had for the driver seat measurement but did not use for the passenger seat measurement.


You have very serious installation/tuning/setup error in first one.
Please take the TDA software and check all ways/bands one by one carefully with very high patience.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> You have very serious installation/tuning/setup error in first one.
> Please take the TDA software and check all ways/bands one by one carefully with very high patience.


That's the Thing. They are the exact same tune! Just one measured from the passenger seat and the other from the driver seat. Somehow the position of when I am Seating makes such a big difference?


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> At the moment, I am measuring sitting in the driver position and painting starting from the wind screen from up to down and moving slowly back to just before the back of the front seats. No lower then the door windows and carefully avoiding the playing speakers by around 15-20cm.


Are your ears at all those places while you're in the car? Just measure at your ears, that all that counts and done.


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> Are your ears at all those places while you're in the car? Just measure at your ears, that all that counts and done.


You should offer that 15 years ago : )))
The focus of APL tools is on loudspeakers. You should follow such procedure to get info how your loudspeakers are performing than you can enjoy the result in almost any place you like.
Of course, if you have time, you can try to use mic stand for measurement ... : )


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> Are your ears at all those places while you're in the car? Just measure at your ears, that all that counts and done.


The instructions and video I seen shows that you have to paint measure the boundary from side window to windscreen but avoid the emitting speakers by at least 20-30cm. Thats what I have been doing.


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> You should offer that 15 years ago : )))
> The focus of APL tools is on loudspeakers. You should follow such procedure to get info how your loudspeakers are performing than you can enjoy the result in almost any place you like.
> Of course, if you have time, you can try to use mic stand for measurement ... : )


In a room you're listening to the speakers, in your car you're primarily listening to the room. Whatever is happening in the rest of the car is already IN what you're hearing....why complicate things? I bet you don't tune by ear.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So, mr nut.....what are you suggesting, that raimonds rewrite his software to work with your measurement technique, or for the ones measuring with apl software to ignore the intended use?


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> In a room you're listening to the speakers, in your car you're primarily listening to the room. Whatever is happening in the rest of the car is already IN what you're hearing....why complicate things? I bet you don't tune by ear.


I did that from 1979 till 2002 : )))
and RTA was ready to use for about 10 years to that time ...


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

​


claydo said:


> So, mr nut.....what are you suggesting, that raimonds rewrite his software to work with your measurement technique, or for the ones measuring with apl software to ignore the intended use?


No Mr claydoh, I'm bantering. Lighten up.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If somebody asked me, what I listen to, so I might agree with sqnut - loudspeakers at home and room in a car. Right, but only for tuning. The rest of my time I listen to music, not loudspeakers. Due to the apl technology the time needed for tuning has been drastically reduced without any compromise in sound quality, on the contrary, it is much better. So all that resulted in more time availablre to enjoy music. 

I have heard that for some people it might sound irritating as tuning was a hobby .... ))

Sendt fra min T1-A21L med Tapatalk


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> You should offer that 15 years ago : )))
> The focus of APL tools is on loudspeakers. You should follow such procedure to get info how your loudspeakers are performing than you can enjoy the result in almost any place you like.
> Of course, if you have time, you can try to use mic stand for measurement ... : )


Would you be able to offer some insights on why I get such different measurement results when measuring from the passenger seat vs driver seat?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> Thanks for your reply. I will listen to MP1 a little longer to see how I like it. For Home audio, I do like the 2-3k dip.
> 
> My 1k and 5-k dips are in the region of 10-15DB. They are pre APL. As I do not have the hardware, I am unable to measure post APL to see if APL filters did fix the problem. It does seem to indicate that it can bring up the 5-7k dip almost to the target level and half the 1k dip. Its just very strange that my crossovers are no where near there and does not seem to impact the dip even when I am changing the slope or type. It also happens on both sides almost equally.
> 
> I be redoing some new measurements with another TA to see if I can get it better which should not be difficult I hope.


You’re welcome! I’m surprised you didn't get more answers.



oliverlim said:


> I think I found out why the measurement result looks so poor! I have been doing the paint measurement from the driver seat. I attached 2 files and you will know immediately which was "poor" result was from the driver seat and which was from the passenger seat. Both are from the Left speakers only.
> 
> Which brings me to the question, why does it look so different? Please ignore the target curve which I had for the driver seat measurement but did not use for the passenger seat measurement.


Really strange indeed.
First, APL is magic, but it still needs a good tune as a starting point.
So what is your setup and where are your drivers?
Here it almost look as if one driver was completely masked by something during the left side sweeps.
Also, the painting method should be used on the entire volume in the same time, not only left and only right. You move around the mic from your driver seat, it’s easier and it will average your total measurements.

Then if you want to compare APL with REW or any other RTA you should use the same points for measurements, or close enough.
But quicks sweeps measuring each sides or one driver at a time just around the head, or even just one point, should be enough to reveal this big issue.
You could also compare both sides with APL, but from each seat.


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> I have heard that for some people it might sound irritating as tuning was a hobby .... ))
> 
> Sendt fra min T1-A21L med Tapatalk


It was an active hobby 4-5 years back and since then, I've just been listening.

It took me a few years and falling on my face a million times, but I finally got to where the car sounds close enough to my speakers at home and for me not have have the urge to tweak any further. So now I just listen.


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> I did that from 1979 till 2002 : )))
> and RTA was ready to use for about 10 years to that time ...


I am clumsy most times  and I hope you will not take my banter out of context. My comments are neither to dis your product, which by all accounts is excellent, nor attack you personally as you are one of the nicest and most helpful retailers on here. 

My simple submission is that once one is intuitive with how speakers really sound in a proper room, dialing in that sound in the car to the point where one can listen without the urge to tweak, is down to doing a large chunk by ear even after using software to set the base. Algorithms will help in balancing and flattening L&R response and getting the timing in the ballpark, so yes it will speed up the process, but a big chunk of work will still need to be done based on what you're hearing and removing the effect of the room bit by bit. Tweaking the timing and shaping the response curve. 

This is so with all auto tune software I've used, but I haven't used APL, which is why I'm not talking about it specifically. Every single difference that one hears between speakers at home and in the car, is quantifiable to a difference in timing, response or phase, because those are the only 3 ways we hear a difference. 

So, as long as the software balances L&R and gets the timing in the ball park and gives me 31 bands / drivers and TA adjustment, both at a fine resolution, I'm good to go. 

But then again not everyone is a nut.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> I am clumsy most times  and I hope you will not take my banter out of context. My comments are neither to dis your product, which by all accounts is excellent, nor attack you personally as you are one of the nicest and most helpful retailers on here.
> 
> My simple submission is that once one is intuitive with how speakers really sound in a proper room, dialing in that sound in the car to the point where one can listen without the urge to tweak, is down to doing a large chunk by ear even after using software to set the base. Algorithms will help in balancing and flattening L&R response and getting the timing in the ballpark, so yes it will speed up the process, but a big chunk of work will still need to be done based on what you're hearing and removing the effect of the room bit by bit. Tweaking the timing and shaping the response curve.
> 
> This is so with all auto tune software I've used, but I haven't used APL, which is why I'm not talking about it specifically. Every single difference that one hears between speakers at home and in the car, is quantifiable to a difference in timing, response or phase, because those are the only 3 ways we hear a difference.
> 
> So, as long as the software balances L&R and gets the timing in the ball park and gives me 31 bands / drivers and TA adjustment, both at a fine resolution, I'm good to go.
> 
> But then again not everyone is a nut.



I feel like you might miss the real value of this tool, because it really helps to focus on the result, by removing most of the burden. Yeah you can say it puts you in the ballpark, but the size of this ballpark is so small it's more a babypark now. And it makes it super easy to adjust here and there without messing with phases and time cohesion.
I mean, it helped me to do exactly what you described. But I agree it still needs some knowledge at first and a good tune, with good TA. That's why we can't really call it an auto-tune.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

One of the positive features of the apl software, that it will allow everybody to tweak further the responce curve with the help of a parametric equaliser based on fir-filters. You can make it unlimited times after demand of personal preferances and feasibility of ears and brain to hear and to perceive the sound. You are not destroing the signal quality by eq and you are not limited to f. ex. 31 bands. Of course, all this will take time especially if taking into account preliminary x-over and TA. But measuring itself could be combined with the selection of the preferred target curve and calibration for a mic. It saves time. Especially if you are experienced and know what to do and what you might expect as a result of your actions. In this context it is difficult or even completely wrong to call this process as auto-tuning. It incorporates knowledge and personal experience. Apl is just a tool providing better sound reproduction, in this case - in a car environment. To my opinion is it an excellent tool first of all for installers and tuning masters, but , could be to certain extend little bit difficult for a newbee. In any case, it worth trying. Talking based on my personal experience after some unsatisfactory efforts to use autotuning from Alpine (Imprint). Hate autotuning, maybe it will be better in future.

Sendt fra min T1-A21L med Tapatalk


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> .... That's why we can't really call it an auto-tune.


Yes, I would like to offer to call it CAD - Computer Aided Design of ...
We must be designers, but computer will aid : )


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

One thing I really like about the APL isn't just that the results are fantastic, but I can lean any direction in the seat and the tune doesn't really change much. Every other tuning tool/method I've used before was very sensitive to the position of my head. Now I can just enjoy it and not have to sit straight up like a mannequin all the time to REALLY enjoy it. I suspect that this is largely because of the method of taking the measurements.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It seems to be a result of focusing on the loudspeaker output mainly, but not on the cabin response. When a sound source plays better, all or the most of other problems will be less audible. At home we have a sweet point for stereo. In a car this will be done by TA, polishing the sound with apl aftetwords. 

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## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It actually quite amazing what APL does. As LumbermanSVO states, it seems to widen the sweet spot to a huge area instead of around the drive head area. I still cant wrap around how the measurements are done over such a large area but it seems to improve the sound almost everywhere. I mean if we were to do a RTA or average measurement of many spots in the same area as the APL paint measurements, I would be sure the EQ done in a normal dsp would sound terrible. That is something I would like to understand if it can be explained in a layman manner.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just in one word - know-how 

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Apl measures acoustic power, not just amplitude of the frequency response 
Actually it is well known method of measuring noise from industrial machines . You should test from all directions. How Raimonds modified this approach for the use in prosound world is an art of science. Actually his algorithm is more advanced than the box itself. If compared its components to other modern dsp's you will not be much surprised. That is why some people simply underestimate such approach and can not understand its possibilities. Positive thing here is one can use apl method even without buying a hardware. You can use it with plugins, convolvers and are not limited to selection of specific OS. I use it both with Windows based components as well as Android devices. 

I am not sure you understand in details how your TV working. Neither do I. But this fact will not stop you in watching TV programmes. 
Just listen music with the help of apl technology and enjoy your time. 

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----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> One thing I really like about the APL isn't just that the results are fantastic, but I can lean any direction in the seat and the tune doesn't really change much. Every other tuning tool/method I've used before was very sensitive to the position of my head. Now I can just enjoy it and not have to sit straight up like a mannequin all the time to REALLY enjoy it. I suspect that this is largely because of the method of taking the measurements.


Thank you very much!

You hit the nail on the head : )


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Apl measures acoustic power, not just amplitude of the frequency response
> Actually it is well known method of measuring noise from industrial machines . You should test from all directions. How Raimonds modified this approach for the use in prosound world is an art of science. Actually his algorithm is more advanced than the box itself. If compared its components to other modern dsp's you will not be much surprised. That is why some people simply underestimate such approach and can not understand its possibilities. Positive thing here is one can use apl method even without buying a hardware. You can use it with plugins, convolvers and are not limited to selection of specific OS. I use it both with Windows based components as well as Android devices.
> 
> I am not sure you understand in details how your TV working. Neither do I. But this fact will not stop you in watching TV programmes.
> Just listen music with the help of apl technology and enjoy your time.
> 
> Sendt fra min GT-I9505 med Tapatalk


It indeed is amazing. Has any of your tried a different target curve then MP1? 
Whats the reason for the dip in 2-3K in MP1? I recall Audyssey target curve having that dip in around the same area as well.


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> It indeed is amazing. Has any of your tried a different target curve then MP1?
> Whats the reason for the dip in 2-3K in MP1? I recall Audyssey target curve having that dip in around the same area as well.


So at the end of the day it is an auto tune++ ......jk. The dip is there because 2-4 khz is where our ears are most sensitive and in a car, reflections are making this range seem louder than what it would be in a normal room. On the MP1 curve is the low end boosted?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Boosted for competition, but for driving is fine. Having children behind I can enjoy music without the sub. This solution needs midbass playing relatively low and dead doors ))


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok fellers, I've got her roughed in, the new dsp setup and playing music.......looks like tomorrow will be the first attempt to run some sweeps and tune in the apl!......I can't wait, may be back for some questions. Once she's up and doing her thing, I'll add my 2 cents!


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## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Ok fellers, I've got her roughed in, the new dsp setup and playing music.......looks like tomorrow will be the first attempt to run some sweeps and tune in the apl!......I can't wait, may be back for some questions. Once she's up and doing her thing, I'll add my 2 cents!



Looks great! Hopefully mine is on the way to me right now!


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Holeeeey shiite.....this thing is fan-freaking-tabulous! I ain't lying boys....this is straight easy once you get through the software hurdles...lol. I just bested my best tune over several years time........in like half an hour.......and this is my first time using it! Jeez.....thanks Raimonds, what a killer device/software combo! Thanks as well to lumberman for the walk thru.......I've never had such left to right precision.....wow, I'm speachless......this is cheating.........

Btw, hats off as well for whomever is responsible for the mp1 curve.......it's tight, real tight!


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok.....so I'm excited......but damn, I mean I had my doubts......I don't know what all this thing is doing with the signal, but it flat works, no ****. I hadn't heard from anyone on here running a "full" system with this thing.....I mean Hanatsu used it in a simpler setup, the most vocal dood used it in a passive setup, lumberman used stock speakers on head unit power.......mine isn't like any of those.......full three way front, morel tweets, 5.5" revelator mids on the dash, 10s in the doors, and a pair of 8" w7s.......so I was hesitant on being the first all out guinea pig on a full system, but damn......I'm not disappointed one bit.......phenomenal work Raimonds!


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok....I'm gonna take a step back, and offer that it's late, and those are strictly first impressions....lol. Give me another day or so for some listening broken up into multiple sessions.......and I'll definitely report back with some more information.......initial impression is blown away tho....can't deny that, hell just look at the previous two posts.....lol. I wasn't in the car for long......so hopefully the impressions stick!


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## Locomotive Tech

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

sub'd!


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> .........
> 
> Btw, hats off as well for whomever is responsible for the mp1 curve.......it's tight, real tight!


Thanks!

It was find in work on this system in 04.09.2004
You may find this date on some mp1`s files.


Two different worlds find common ideas : )))


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am using apl with 3 way passive front in 3 years. Never regret purchase of the apl technology. Now I have OT everywere. Home stereo, earphones, tablets and Android smartphone. When I started first thread on apl in 2014, nobody believed me. Apl has really change my mind. It is great!

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## naiku

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Holeeeey shiite.....this thing is fan-freaking-tabulous! I ain't lying boys....this is straight easy once you get through the software hurdles...lol. I just bested my best tune over several years time........in like half an hour.......and this is my first time using it! Jeez.....thanks Raimonds, what a killer device/software combo! Thanks as well to lumberman for the walk thru.......I've never had such left to right precision.....wow, I'm speachless......this is cheating.........


Your build thread brought me here! Looking forward to another demo on the Cobalt in a few weeks time. 



oliverlim said:


> Can you explain more about the android device? i do not see it on your web site.





Alextaastrup said:


> What Raimonds suggests is an app called Viper4android, which comprises an convolver capable to work with the 7files made from measurements carried out by the Workshop.
> 
> So you do not need apl1 box in a car, if you have android based head unit or smartphone as a source.


So, this now has me very interested. I have a Nexus 7 in a fixed install in my car. Currently using a USB-DAC and optical into the DSP. Am I right in that I need to use the APL software to take measurements, then to use the Viper4Android app on my tablet to interpret those measurements? Anything I need to also do with the DSP? I have TA and EQ set, but am interested in seeing how much further I can take the tune.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You will have 4096 taps with Android device and without hardware (apl1 box) 

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The best is to use TDA APL software for TA. 

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



naiku said:


> Your build thread brought me here! Looking forward to another demo on the Cobalt in a few weeks time.


Ian, I'm looking forward to letting ya hear it! It's a slick solution to gremlins I've been fighting for a loooong time.......sorry, but I know nothing about the plug in deal for android.


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Okay, I've spent more time in the car now, and I'm still impressed with what the apl can do......I've just started using the selector switch, and it's so much fun to be able to switch between curves in real time, it's almost instant!
Just switching between the preset curves right now, I'm soon to experiment making my own curves, this is going to get interesting fo sho......having lots of fun with this unit!


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Claydo, How is going? Have you made some more tests with apl? It is possible to check how apl is approaching the target curve. Let say strait line for the whole frequency range. Then MP1...

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Claydo, How is going? Have you made some more tests with apl? It is possible to check how apl is approaching the target curve. Let say strait line for the whole frequency range. Then MP1...
> 
> Sendt fra min GT-I9505 med Tapatalk


It's going rather well, still finalizing the mount for the multi switch, and other than that I've been just enjoying the sounds! I've strayed from mp1 a bit, and I'm working on my own personal curves......so far I've been touching up the tonality for my tastes with the 99 before the apl unit, but as soon as I figure out getting the parametric eq in c1 to save as target, I'm going to leave the eq duties strictly within the apl unit. Still impressed, this thing is awesome! I don't know how it does what it does, but it corrects a lot more than just the response.....


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It is easy to confirm by using TDA APL program: with apl1 and bypassing it. Correct, it does much more than usual frequency response EQ. Try this option.

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I haven't ran any tda measurements in a while......I will eventually, but for now I'm focused on making my own curve presets......


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

OK. Right, but it is interesting

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> OK. Right, but it is interesting
> 
> Sendt fra min GT-I9505 med Tapatalk


Yes, it is....I purchased the tda software a ways back and it's a great tool.....once I get time I'll definitely run a with apl/without tda measurement to see how much it has changed things! I also want to run some individual driver tda sweeps (something I saw raimonds recommend) to see if any driver in particular has room for physical improvements as well.....


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Do not forget to check how your preset fits to the desired curve. One more Workshop measurement is needed for this purpose. 

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Do not forget to check how your preset fits to the desired curve. One more Workshop measurement is needed for this purpose.
> 
> Sendt fra min GT-I9505 med Tapatalk


What I really want to do is make a curve in c1 and save it, then use it as a target in apl workshop....haven't gotten this far yet, but it is my goal.......


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok, guys, Raimonds sent me an excellent email about different ways to program your own curve via parametric eq in c1, and it works beautifully! There is more than one way to do it, but for simplicity and comparison/tweaking I've been using the option to write the curve in c1 save it as a text file, send it to the preset folder in apl workshop "data" and then apply the different curves before I "calculate" on my base "corrected" measurements.......once you figure out you must place your data file into the preset folder to get it to work, it's awesome......allows quick tuning to different curves off of one set of measurements, by simply changing the preset on your corrected file and then re-calculating..........and with the preset switch, you can load up to 15 of these curves..........I LOVE IT!!!


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Stop man you're making me want one. 


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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Stop man you're making me want one.
> 
> 
> Sent from my iPhone using Tapatalk Pro


Wait till yer demo and ya see the fun of the "curve" swapping in action! Lol, it's very interesting to hear the differences in real time, but I noticed when you do this the new curve sounds very strange........it actually sounds better if ya drop the volume when swapping and take in the curve as a whole, instead of concentrating on the changes.........it's kinda an odd phenomenon......


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## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Wait till yer demo and ya see the fun of the "curve" swapping in action! Lol, it's very interesting to hear the differences in real time, but I noticed when you do this the new curve sounds very strange........it actually sounds better if ya drop the volume when swapping and take in the curve as a whole, instead of concentrating on the changes.........it's kinda an odd phenomenon......



Awesome! Yeah that actually makes great sense that you'd probably want to mute it even very low volume during the change, so you're perceiving just tonality rather than what changed. 


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Stop man you're making me want one.


You know you want one!


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## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Clay gets to help train me on mine at the meet. 


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> You know you want one!


Gotta let him hear it first! Then show him the simplicity in the tuning.....then, well.....we'll see.....lol.


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Clay gets to help train me on mine at the meet.
> 
> 
> Sent from my iPhone using Tapatalk


Hopefully we will get you up and running! Certainly don't mind trying to figure it out with ya, I think yer gonna like it when it does its thing, takes an ungodly (as you well know, lol) process and simplifies the hell out of it! Are you still having the distortion issues? The apl required a complete re-working of my gain structure......


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## dcfis

Are most using this as a mini dsp compliment or a replacement?


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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dcfis said:


> Are most using this as a mini dsp compliment or a replacement?



Ooh ooh Mr Kotter! I can answer that. Had a revelation of a discussion with Clay on that. My take is it's used in compliment with another DSP which handles you XO, TA and basic leveling with appropriate gain structure as stated so the APL handles ALL the EQ. 

So DSP: 
Crossovers
Time Alignment 
Leveling

APL: 
EQ.. All of it. Which includes phase correction etc. 

So you get TA dialed in for each side tweeter on down, then it runs through its magic for each whole side individually. Then you fine tune left and right TA to center. 

If I got all that correctly. 

Yeah I kinda want one now. 


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## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Awesome! So it sits before the DSP in the chain? I think I got a pro audio guy willing to work with me


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## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yes in front of everything. It needs an already good system to really shine.


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## slvrtsunami

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

sub'd!!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Remember, that you can delay fir-filters separately for each channel practically without any limits. I have more than 50 msec in my present car.

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## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

I spent better part of a Saturday just doing initial individual driver work, which might just be my way of way too much OCD tuning, and that is only crossover and trim work to get the drivers playing flat. Still have fine TA phase work and pairs and side EQ work then overall and simply hope I can shape to a curve. 

I'm really thinking one of two things will happen here.. An APL1 or Smaart mic array. Clay's making me really consider the easy route. 


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----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> I spent better part of a Saturday just doing initial individual driver work, which might just be my way of way too much OCD tuning, and that is only crossover and trim work to get the drivers playing flat. Still have fine TA phase work and pairs and side EQ work then overall and simply hope I can shape to a curve.
> 
> I'm really thinking one of two things will happen here.. An APL1 or Smaart mic array. Clay's making me really consider the easy route.
> 
> 
> Sent from my iPhone using Tapatalk Pro[/QUOTE
> 
> 
> You got an apl ,? Nice


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> You got an apl ,? Nice



Nope. I'm still manual.  Sony goodness into Helix goodness. That's all. 


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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Man, I'll tell you what, this is a solid piece, and an investment I'm glad I made. Since I've learned how to model my own curves in c1 and transfer them as target curves in workshop, this thing has surpassed every expectation I had, and flat shines once tailored to your personal curve. My system has never sounded better. I've had enough time with the unit for the "wow, new" to wear thin, and all I can say is, you can have my apl1......when you pry it from my cold dead hands, lmao. Wonderful tech Raimonds, and excellent implementation......


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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Man, I'll tell you what, this is a solid piece, and an investment I'm glad I made. Since I've learned how to model my own curves in c1 and transfer them as target curves in workshop, this thing has surpassed every expectation I had, and flat shines once tailored to your personal curve. My system has never sounded better. I've had enough time with the unit for the "wow, new" to wear thin, and all I can say is, you can have my apl1......when you pry it from my cold dead hands, lmao. Wonderful tech Raimonds, and excellent implementation......













I told Raimonds I was anxiously awaiting hearing this bad boy. 



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## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How much are these units, and where can you get one? I'm very curious now myself. Clay's car sounding any better?!


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## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If I read correctly, It can do Optical in from headunit then Optical out to my DSP?


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> I told Raimonds I was anxiously awaiting hearing this bad boy.
> 
> 
> 
> Sent from my iPhone using Tapatalk Pro





crackinhedz said:


> How much are these units, and where can you get one? I'm very curious now myself. Clay's car sounding any better?!


I can't wait to show it off for you guys! I'm very eagar to see what yall think.....

Pricing can be seen at acoustic power lab's website. The car is definitely more sharp on the "technical" side than its ever been.....fun stuff, of course I've got a custom curve that reflects my own tastes, so it will be familiar to what you may have heard in the past, with a good dose more realism/accuracy.......



crackinhedz said:


> If I read correctly, It can do Optical in from headunit then Optical out to my DSP?


This is correct, there is digital in and out.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Pricing can be seen at acoustic power lab's website.


I did find their "buy" page, but there are so many add on's not sure what is necessary?

APL1
TDA eq?

License? what qualifies as academic or student license?


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Apl1 is the eq unit itself....of course there is multiple input output options on the apl1, I don't need any of the professional style inputs and outputs, the rca unit has the optical and coaxial inputs and outputs along with the rcas. ...apl workshop is the software that constructs the fir filters. You have to have these two......the tda software is a time alignment tool, that is very cool on its own for a visual display of signal alignment, that's much more intuitive than impulse response graphs (in my opinion), but is completely optional, and is not required to operate the apl1 unit. The tda eq is yet another software suite that builds filters for the apl1 eq, but I've read isn't as compatible with our automotive applications as apl workshop........Raimonds can explain it better, and I initiated contact through pm here, so hit him up and I'm sure he'll get back with ya.


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## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

It sounds like you can be like "I think I want this curve today" and Bam!
That alone is like cheating. That and FIR IMO is worth the price of admission. It's seriously tempting. It's like MS-8 for big boys who can do their own XO's, leveling and TA. My fear is what I might do after hearing it. 

Sent from my iPad using Tapatalk


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> It sounds like you can be like "I think I want this curve today" and Bam!
> That alone is like cheating. That and FIR IMO is worth the price of admission. It's seriously tempting.
> 
> 
> Sent from my iPad using Tapatalk


Yup......you can take the coneq software (included with workshop btw) and build any curve that tickles yer fancy, save it, then go into workshop and apply that curve as a target over top of your corrected measurements, over and over.........in like 10 minutes.....it will take you longer to construct the curve than it does to load it on top of your correction file........once you have that correction file, you can change the curve however many times you please, without requiring any new measurements.......lol, it's way too easy. To change a curve without measuring for hours, and risking massive disruptions to your corrective actions in your eq is HUGE for me..........

Not to mention the fact that with the 15 position switch option, you can right and save 16 different curves on the apl1 unit and swap em on the fly. So Eric, I highly recommend that switch option with the apl1 unit itself.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Next weekend I'll let you guys put ears on it, you've both heard my car before, so you can build your opinions knowing where the car was (not bad, imo) to where it is now (see if ya like it) and discuss the finer points and advantages......you honestly wouldn't believe the measurement system, it's so different than anything else I've ever heard of.......so I'll just show ya!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Cool, I'm glad more and more people start using this.
We’ll get more discussions around the process to further optimize!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Once more time - it is possible to delay FIR filters with apl-software. Than you can apply focusing on different points in the cabin volume and switch beteween them by 16-positions switch. For example: driver position, passanger in a front, etc. Eq-ing of your present house curve is unlimitted by C1 parametric equalizer, but requires PC with Workshop installed and 10 minutes max. So, for me apl is a time machine, saving me a lot of time 
Regarding pricing - yes, ir is not a budget class unit, but every penny you've paid worth such a bargain. On the other hand, if you have Android or Windows based HU, you do not need even to buy apl1 box, replacing it with the plugin. This solution is 3 times cheaper with the same result in the sound quality. 

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## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> if you have Android or Windows based HU, you do not need even to buy apl1 box, replacing it with the plugin. This solution is 3 times cheaper with the same result in the sound quality.


I have a windows headunit, so I don't need an APL1 just need the software? (Which plugin?)


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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Clay when you and John dive into the APL1 stuff I definitely would like to see the software and the nitty gritty involved in the process. Been reading back through the thread. That usually means I'm serious and about to do a bad thing. LOL 


Sent from my iPhone using Tapatalk Pro


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> I have a windows headunit, so I don't need an APL1 just need the software? (Which plugin?)


Apl EP1 v1.22 for Foobar2000. Plugin is to be found on the Acoustic Power lab site. You need to measure your system with the help of Workshop and upload FIR files to this plugin.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Clay when you and John dive into the APL1 stuff I definitely would like to see the software and the nitty gritty involved in the process. Been reading back through the thread. That usually means I'm serious and about to do a bad thing. LOL
> 
> 
> Sent from my iPhone using Tapatalk Pro


Shouldn't be a problem at all Scott.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Apl EP1 v1.22 for Foobar2000. Plugin is to be found on the Acoustic Power lab site. You need to measure your system with the help of Workshop and upload FIR files to this plugin.


very cool.

Is this plugin limited to only foobar? In other words will it EQ everything audio out through windows or just through foobar? I use Centrafuse for music.


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Subject came up on the APL1 resolution verses higher resolution source and DSP, making the 24bit/48khz resolution being a bottleneck. Hopefully the chipset upgrades might be in consideration/development, since high-res hardware is becoming more accessible in ADC's DAC's and DSP's? Sabre, AKM, Ti etc



However, if 48kHz/24bit was currently a deal breaker, the APL1s is 48 and 96khz capable. And conveniently, has a DC power input.. 7.5vDC. Dunno how capable it'd be to implement in-car.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Every player which accepts vst plugins. Rajmonds has mentioned also a possibility to use it at driver level for the whole Windows, but I have not tried yet. It works perfect with foobar, which is my favorite player... 

You might be also interested in software X-over called dephonica (Windows based).

Basically apl1 is not so impressive compared to other DSP's if looking only on the list of components. What makes deal is a theory behind and perfectly designed algorythm, which is VERY different from other devices on the market in our days. More over, it is patent protected. Rajmond suggested to measure acoustic power magnitude for the whole frequency range, but not a frequency response in one point. His theory is focusing firstly on loudspeakers and applying some psykoacoustics to achieve best results to ears, not to a microfon.... Ears listen some differently. Said that, software from Acoustic Power Lab to my mind is more important. Forgot to mention that fir filters could be produced and treated in different ways. Rajmond really knows what to do with them. For me - results are still amazing after 3 years of use. Now I have fir filters for every par of speakers and cans at home. Never regret.

Sendt fra min GT-I9505 med Tapatalk


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So is this what I would need to buy?

APL Workshop
APL TDA EQ
APL EP1 VST-plugin


Also, 16 preset option for any APL1 version: 50€


the 16 preset, how would that work directly from the PC?



Sorry for the questions (Alex your PM was full) Thanks for the help, trying to get an idea of how much I need to save for!


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> So is this what I would need to buy?
> 
> APL Workshop
> APL TDA EQ
> APL EP1 VST-plugin
> 
> 
> Also, 16 preset option for any APL1 version: 50€
> 
> 
> the 16 preset, how would that work directly from the PC?
> 
> 
> 
> Sorry for the questions (Alex your PM was full) Thanks for the help, trying to get an idea of how much I need to save for!


If you want to use the android option, you would only need the plug in and apl workshop. The 15 position switch is for the apl1 eq, by using the plug in you are not gonna have that unit. The tda eq is is another software suite, that builds fir filters, but workshop fits our application better. The tda (just tda, no eq) is the time alignment measurement software, it's a very handy tool for setting up your system, however not required to get you up and running with the workshop measurement software.......


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> If you want to use the android option, you would only need the plug in and apl workshop. The 15 position switch is for the apl1 eq, by using the plug in you are not gonna have that unit. The tda eq is is another software suite, that builds fir filters, but workshop fits our application better. The tda (just tda, no eq) is the time alignment measurement software, it's a very handy tool for setting up your system, however not required to get you up and running with the workshop measurement software.......


Clay so for what you're doing, other than _APL TDA measurement software_ which I have already, you need the following??
Actual APL1 device + 16 preset option
_APL TDA EQ measurement and equalizer synthesis software_ and 
_APL Workshop_
?


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nope, read that quoted post a lil closer....lol. Essentially tda eq and workshop are both fir filter building and measurement softwares. Workshop is the software recommended for car audio applications. Workshop is what I'm using to setup my apl unit. So I purchased the apl1, workshop, and the 15 switch option.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Nope, read that quoted post a lil closer....lol. Essentially tda eq and workshop are both fir filter building and measurement softwares. Workshop is the software recommended for car audio applications. Workshop is what I'm using to setup my apl unit. So I purchased the apl1, workshop, and the 15 switch option.


Gotcha. Thanks.. So ordering if a guy needed would look like:

APL Workshop: 320€
APL1 RCA unit: 510€
16 preset option for any APL1 version: 50€

Hmm.. I wonder if a guy offered to do a thorough "how to" vid series for the car guys doing this, from setup to boogie, maybe Raimonds might entertain a sponsor deal for helping educate the DIYMA community how slick it is and how to do it?  I just ran the currency conversion in google and a huge pop up came up saying "No Babs, you can't have one!" True story. LOL!


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> I just ran the currency conversion in google and a huge pop up came up saying "No Babs, you can't have one!" True story. LOL!


Ok, but this is before you hear my 30 minutes, start to finish tune.......... We shall see if that experience is enough of a Pop up blocker for ya, lmao. 

Let that sink for a minute.........30 minutes........and I haven't futzed with anything but tonality curves since........no desire for change..........


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> ...without measuring for hours...


That part is HUGE! Just recalculate using your original measurements! I have screen shots of the Miata with stock mids and after I replaced them with the IDQ8's, I should post them... The measurement after adding the horns and amp should be fun too 



Babs said:


> Hmm.. I wonder if a guy offered to do a thorough "how to" vid series for the car guys doing this, from setup to boogie, maybe Raimonds might entertain a sponsor deal for helping educate the DIYMA community how slick it is and how to do it?  I just ran the currency conversion in google and a huge pop up came up saying "No Babs, you can't have one!" True story. LOL!


I have the gear, know-how, and software to make such a video. What I rarely have is time. Maybe after I get back from Hawaii I'll be able to put something together. I am (slowly) working on a PDF user manual too. I've learned more since my big step-by-step posts in this thread.

Also, I need to dig up an email I have from Raimonds about modding the switch to be a simple 2-tune switch. That mod will be for my top up/top down tunes.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Clay, can you shed a little insight into measuring? Is it done at the listening position or all around the car? Also, can I use a usb mic? Curious how its so much quicker


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Clay, can you shed a little insight into measuring? Is it done at the listening position or all around the car? Also, can I use a usb mic? Curious how its so much quicker


I use the MiniDSP USB mic and load the calibration file into Workshop, works like a charm. 

Also, you can open the mic, flip some DIP switches, and make it less sensitive. I did this and it kinda helps that I can now turn up the volume MUCH louder to overpower the ambient noise. But I only drive convertibles, so that might not be a factor for you.

When measuring with the APL you take measurements all around the car. Raimonds recommends covering the entire seating area in the front, from the dash to the doors, and roof to the seats. I'm only doing a one seat tune, so I did this on just the driver side. He also recommends not getting too close to any speaker.

While it may sound tedious to measure such a huge area, vs just a single point, it actually only takes a few minutes to get 200+ measurements for both the left and right side speakers.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Clay, can you shed a little insight into measuring? Is it done at the listening position or all around the car? Also, can I use a usb mic? Curious how its so much quicker


Measurements are quick an easy, and yes, a usb mic is fine. I simply started my measurement with the mic at the top of the side glass on the same side as the drivers I'm measuring, then down stroke to the bottom of the glass, then up to the headliner bout 2" out from the side glass, then down the arm rest, over two inches..............simply repeat these "strokes" like you're painting a wall about 10" from the dash, all of the way across the interior ending up at the opposite side glass from where ya started. To reach the desired number of measurement points (I targeted 200 per side, for no particular reason) I would continue back across the car ending at the listening position. The whole time you're doing this the software will be measuring at different points and keeping a climbing tally of the amount of points in a little window. Simply repeat a mirror image of this pattern for the opposite side speakers, "painting a wall" across the car in the same pattern. Takes like 5 minutes. From these actions, the software calculates your response curves (by automatic averaging, I'm guessing) and spits them out at you.......hit another button and it configures a correction pattern, and presents that.........may sound complicated, but it's incredibly easy!


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Lol, lumberman, ya beat me to it........seems our techniques differ a bit! In my car with the windows up ambient noise barely even appeared in my measurements.......

Oh....and my dayton usb mic's calibration curve wouldn't load into the workshop software, apparently not being the right format.......but Raimonds, helpful as always, had me send it to him, and he put it in a format the apl software could recognize!


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Ok, but this is before you hear my 30 minutes, start to finish tune.......... We shall see if that experience is enough of a Pop up blocker for ya, lmao.
> 
> 
> 
> Let that sink for a minute.........30 minutes........and I haven't futzed with anything but tonality curves since........no desire for change..........



Yeah I really gotta see it and hear it to believe it.. I fear if it's not too good to be true, and if a buyer picks up my 99RS, I may be at the meet adding to a cart on APLaudio. Hehehe. Don't let me get all clickity click on my phone. LOL!


Sent from my iPhone using Tapatalk Pro


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just think, if we can get John's apl up and working, ya may be able to demo two apl cars at this meet! I hope we can get the audi going, because his car would probably present an opportunity to compare his traditionally tuned dsp, to the apl directly on the same system, because I have a feeling he's already tuned the wheels off that system with the helix........where my dsp has no eq tune on it at all for comparison.......


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Just think, if we can get John's apl up and working, ya may be able to demo two apl cars at this meet! I hope we can get the audi going, because his car would probably present an opportunity to compare his traditionally tuned dsp, to the apl directly on the same system, because I have a feeling he's already tuned the wheels off that system with the helix........where my dsp has no eq tune on it at all for comparison.......


Phst, mine is already working fine! (assuming it didn't get damaged from the hail, wait, I am named John too) 

Babs, If things work out, I'd be glad to drive to NC for some one-on-one tuning time with my APL. And by one-on-one, I mean you'll be doing every every click on the computer, and be waving the mic around like a spastic fool. Just gimme about 3-4 weeks. After that, the "you can't afford this" pop up will disappear from your browser


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Phst, mine is already working fine! (assuming it didn't get damaged from the hail, wait, I am named John too)
> 
> Babs, If things work out, I'd be glad to drive to NC for some one-on-one tuning time with my APL. And by one-on-one, I mean you'll be doing every every click on the computer, and be waving the mic around like a spastic fool. Just gimme about 3-4 weeks. After that, the "you can't afford this" pop up will disappear from your browser


If you come up his way, let me know too and I'll drive over from Knoxville. I already have an APL1 but haven't had time to install my system. And I keep waiting for one of those not so fancy "quick-start" videos.

And if you're interested in home theater, I might be able to arrange a demo at my friend's house in Knoxville where he is running a pair of my 24" subwoofers and an 18" in the rear. Not a fancy theater but it's nice with performance that has to be experienced to be believed.

Oh yeah, dinner on me and I'll use Marriott points for a hotel if you need it.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Babs, there's really no need for a video. It was asked a lot of time and sure it could always help, but this thread and few others cover it all.
I can share some pdf if you want but everything is here already.

It is honestly not as simple as everybody seems to say here.
Well it can if everything works fine at first, like with drivers on winshit, mic calibration, ambiant noise & interference levels and final distortion. But all principles you know already.
It's a bit of burden at first, but the logic, the process is clear. After it's jut some button press.
- measure with infinite sweeps the spfr, 200+ points everywhere in the front cabin. One point every 4" for example in all dimensions , with few areas to avoid (here it's car/setup dependant, you'll be the only one to know what's best after trying)
- define target and filters (txt files, few options on target levels, mic compensation, range etc, easy stuff)
- load to device, listen, and enjoy


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> If you come up his way, let me know too and I'll drive over from Knoxville. I already have an APL1 but haven't had time to install my system. And I keep waiting for one of those not so fancy "quick-start" videos.
> 
> And if you're interested in home theater, I might be able to arrange a demo at my friend's house in Knoxville where he is running a pair of my 24" subwoofers and an 18" in the rear. Not a fancy theater but it's nice with performance that has to be experienced to be believed.
> 
> Oh yeah, dinner on me and I'll use Marriott points for a hotel if you need it.


I'm very familiar with your 24's, I have a pair of MkII's in their shipping crates at home, and on just 350 watts a piece(with a weak preamp) they are enough to piss off everyone in the house! I'd love to listen to some Mariana's on real power and see your craftsmanship in person. I'd also be glad to teach you how to tune with your APL. A day with Clay and I sharing methods might just be phenomenal!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> It is honestly not as simple as everybody seems to say here.


If you look back through this thread, you'll see that I was one of the folks going WFT? after getting my APL1. After several reads of this thread and Raimonds quick start guide(language barrier!) I was able to figure it out.

Now I have no doubt that if I were sitting in front of the average person that could understand their average processor, that I could teach them how to make measurements and corrections, an that when I'm done it would be easier than the MS-8.

I say this as a guy who could financially lose by convincing you of this!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> If you look back through this thread, you'll see that I was one of the folks going WFT? after getting my APL1. After several reads of this thread and Raimonds quick start guide(language barrier!) I was able to figure it out.
> 
> Now I have no doubt that if I were sitting in front of the average person that could understand their average processor, that I could teach them how to make measurements and corrections, an that when I'm done it would be easier than the MS-8.
> 
> I say this as a guy who could financially lose by convincing you of this!


Haha, well you don't have to convince me of anything, I know how simple it can be once you master it, I just went a different route.
But, and like you just explained, I just wanted to be clear that there's a step at first. Not so much about the process itself but about how to adapt and embrace it to your car/setup.
I think it took me few hours/days in the car and here to get a clean first tune. While at the end only few minutes to radically change the target every morning before leaving.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Phst, mine is already working fine! (assuming it didn't get damaged from the hail, wait, I am named John too)
> 
> 
> 
> Babs, If things work out, I'd be glad to drive to NC for some one-on-one tuning time with my APL. And by one-on-one, I mean you'll be doing every every click on the computer, and be waving the mic around like a spastic fool. Just gimme about 3-4 weeks. After that, the "you can't afford this" pop up will disappear from your browser



I may be taking you up in it.. Just got paid for the 99RS for sale. Ruh row Shaggy!


Sent from my iPhone using Tapatalk Pro


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hmm. If I get crazy and buy this thing.. Maybe a mini-meet-APL-tuning extravaganza in Ashevegas. 


Sent from my iPhone using Tapatalk Pro


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I think it took me few hours/days in the car and here to get a clean first tune.


Reading the posts, it can be VERY intimidating at first. Especially before you actually have the hardware and software to play with!


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Reading the posts, it can be VERY intimidating at first. Especially before you actually have the hardware and software to play with!



I imagine from what I've seen with TDA time alignment tool, the learning curve can be a killer. 


Sent from my iPhone using Tapatalk Pro


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> I imagine from what I've seen with TDA time alignment tool, the learning curve can be a killer.
> 
> 
> Sent from my iPhone using Tapatalk Pro


TDA is easy compared to Workshop! But don't let that hold you back! Once you understand what is going on, it's REALLY very simple.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> TDA is easy compared to Workshop! But don't let that hold you back! Once you understand what is going on, it's REALLY very simple.



Documentation is key. If there's at least an explanation, it can't be worse than mastering REW or Smaart or something. 


Sent from my iPhone using Tapatalk Pro


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Wonder how consistent it is? Meaning if you plug in a curve and measure, how much variation might there be if you did that a few times? I'd imagine your mic measurement technique is the biggest crucial item. 


Sent from my iPhone using Tapatalk Pro


----------



## oliverlim

Babs said:


> Wonder how consistent it is? Meaning if you plug in a curve and measure, how much variation might there be if you did that a few times? I'd imagine your mic measurement technique is the biggest crucial item.
> 
> 
> Sent from my iPhone using Tapatalk Pro


In my many test (over 5-6 rounds of measurements), it looks pretty consistent. Even though I am sure sometimes I move faster, sometimes slower, some times lingering more at certain areas etc. Sometimes missing out certain areas etc. Also each round the measurement differs from 150-300 measurements points. And all the measurements looks pretty consistent.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> If you want to use the android option, you would only need the plug in and apl workshop. The 15 position switch is for the apl1 eq, by using the plug in you are not gonna have that unit. The tda eq is is another software suite, that builds fir filters, but workshop fits our application better. The tda (just tda, no eq) is the time alignment measurement software, it's a very handy tool for setting up your system, however not required to get you up and running with the workshop measurement software.......


Actually you will need plugin only for Windows version. For Android one should find app with a convolver on the google play. I use Viper4ANDROID. Raimonds will generate irs-files based on your Workshop measurements. 16-positions switch works only with a physical box apl1.


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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> I hope we can get the audi going, because his car would probably present an opportunity to compare his traditionally tuned dsp, to the apl directly on the same system, because I have a feeling he's already tuned the wheels off that system with the helix........where my dsp has no eq tune on it at all for comparison.......



Actually, right now all I have done on my current tune since putting the car back together is to make it perfectly flat and set crossovers. It's playing and can be listened to, but does not sound great at all right now.

I used Smaart v8 to EQ each speaker perfectly flat using a minimum number of parametric filters. 10 or less for each driver. There is a really cool trick with Smaart you can do where you measure both the speaker and the DSP output at the same time. You invert the DSP output so that when you cut an EQ band it shows on the screen like a boost. You capture a static image of the raw speaker response, and then your draw the DSP EQ filters on top of the line of that raw response. It's like tracing. When you apply EQ filters that are inverted over the top of the raw speaker response, the result is perfectly flat speaker response.

If your speaker is playing flat, that means your phase response will be very smooth. It also means that your crossover filters in the DSP will be the same as the acoustic crossover result. So, for example, if you enter 400 Hz @ 24dB in your DSP, you will actually get 400Hz @ 24dB from the speaker if your speaker response is flattened first.

With flattened speakers, setting up your crossovers is so much easier. You'll have smooth a predictable phase response. And setting your speaker timing with a phase plot is so much easier when you have smooth phase plots to look at.


I'm hoping to use the APL1 to apply a tonality curve to my flat system. Sort of like an input EQ on a pro mixer. I think if we load a target curve with a tilt to it, it should be able to apply that.


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Actually, right now all I have done on my current tune since putting the car back together is to make it perfectly flat and set crossovers. It's playing and can be listened to, but does not sound great at all right now.
> 
> 
> 
> I used Smaart v8 to EQ each speaker perfectly flat using a minimum number of parametric filters. 10 or less for each driver. There is a really cool trick with Smaart you can do where you measure both the speaker and the DSP output at the same time. You invert the DSP output so that when you cut an EQ band it shows on the screen like a boost. You capture a static image of the raw speaker response, and then your draw the DSP EQ filters on top of the line of that raw response. It's like tracing. When you apply EQ filters that are inverted over the top of the raw speaker response, the result is perfectly flat speaker response.
> 
> 
> 
> If your speaker is playing flat, that means your phase response will be very smooth. It also means that your crossover filters in the DSP will be the same as the acoustic crossover result. So, for example, if you enter 400 Hz @ 24dB in your DSP, you will actually get 400Hz @ 24dB from the speaker if your speaker response is flattened first.
> 
> 
> 
> With flattened speakers, setting up your crossovers is so much easier. You'll have smooth a predictable phase response. And setting your speaker timing with a phase plot is so much easier when you have smooth phase plots to look at.
> 
> 
> 
> 
> 
> I'm hoping to use the APL1 to apply a tonality curve to my flat system. Sort of like an input EQ on a pro mixer. I think if we load a target curve with a tilt to it, it should be able to apply that.



Ooooh. Answers that question about the Audi giving a good pallet to paint upon. This'll be fun!

John do that to mine. Do that to mine. LOL!

Sent from my iPhone using Tapatalk Pro


----------



## subterFUSE

Babs said:


> Ooooh. Answers that question about the Audi giving a good pallet to paint upon. This'll be fun!
> 
> John do that to mine. Do that to mine. LOL!
> 
> Sent from my iPhone using Tapatalk Pro



That's actually a really good way to describe it.

Having a flat tune on your system is like having a blank, white canvas to paint on. You can really do anything with it.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> That's actually a really good way to describe it.
> 
> Having a flat tune on your system is like having a blank, white canvas to paint on. You can really do anything with it.


This is OT from thread but when you say flat, I assume that means you're doing each driver to it's electrical crossovers as well so the slopes as well as "crown" of the driver are done at your individual driver stage? Thus making that predictable phase etc. I'm amazed at how off my electrical vs acoustic crossovers are, and how drivers will not budge acoustically with electrical xo adjustment.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> It is honestly not as simple as everybody seems to say here.
> Well it can if everything works fine at first, like with drivers on winshit, mic calibration, ambiant noise & interference levels and final distortion.


I will certainly admit to getting the software up and working together being a royal *****, lol. I am by no means a "computer guy", honestly, I hate them! Luckily with the quick start guide and lumberman ' s posts here, I was able to muddle my way through it........it took me several hours to set it all up, with multiple installs of c1, and some driver errors, understanding of some lingo I wasn't familiar with (root drives and such)......but lumbermans posts helped with some of the language issues of the qsg, and I finally got it, didn't even have to bug Raimonds via email too much.....lol. As far as the tuning tho.....that I thought was pretty slick, once you read enough about it in this thread, and other than figuring out that my gain structure had to change, my first tune was a nasty mess of distorted signal, I was off and to the races!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Wonder how consistent it is? Meaning if you plug in a curve and measure, how much variation might there be if you did that a few times? I'd imagine your mic measurement technique is the biggest crucial item.
> 
> 
> Sent from my iPhone using Tapatalk Pro


Super consistent!
That is one of the strong benefit of the spfr, it doesn't change a lot depending of your measurements. With 50 pts you get already an idea, 200 should be plenty good, more will just add a little to nothing.
So you could build up your curves by merging all new measurements every time, as soon as it the same pre-tune/levels/environments etc.

Also something else, be ready to re-tune your pre-tune.
The spfr will show any weakness, around XO, beaming issues etc


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll make a vid on this (again), since I lost my work last time. Been super busy at work so I'll be doing it during April sometime


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Glad to have ya back hanatsu......your initial review and info is a big part of why I had to try this apl stuffs! I'm curious if you ever implemented the apl into your "main" build"?


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Agreed. Good to see you Hanatsu. 


Sent from my iPhone using Tapatalk Pro


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello Friends!

Thank you for taking participation in this thread!

But some important announcement for all APL1 owners and users!

Due to very high static voltage possible on car chassis,
due to very high voltage possible on PC chassis because of leak from power mains,
due to fact that USB connectors and cables may be not so fresh
and even APL1 unit`s USB input has pretty good surge protection,

please make a grounding connection between car`s and PC`c chassis before
making (or disconnecting) USB connection between PC and APL1!

And answer about Babs ideas of APL1s use.
Apl1s is too much heavy for car : )
There is 96 kHz firmware available for APL1. Just ask!


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> There is 96 kHz firmware available for APL1. Just ask!


Raimonds,

Are there any technical limitations for the APL1 when using this 96Khz firmware?


Do you recommend the 96kHz firmware if we wanted to use the APL1 in combination with a hi-rez source like the Sony RSX-GS9 which plays DSD files?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

We will little bit sacrifice the ability to sharply equalize very low frequencies by use of 96 kHz firmware. It is like switch from 4096 taps to 2048 taps on 48 kHz.

You should keep hi-rez signal path all the way to really enjoy it.
Your DSP and amplifiers must meet that as well.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Should we make new measurements with Workshop after apgrading the firmware for apl1?

Sendt fra min GT-I9505 med Tapatalk


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thank you Raimonds.. Question then becomes if a person wants to sacrifice the FIR taps for a little extra resolution. I'd vote no at first at least. 


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----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Should we make new measurements with Workshop after apgrading the firmware for apl1?
> 
> Sendt fra min GT-I9505 med Tapatalk


No, you just need to set "96 kHz" as output filter sample rate and click "Calculate" for respective measurement in Workshop.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> No, you just need to set "96 kHz" as output filter sample rate and click "Calculate" for respective measurement in Workshop.



Ah so the switch is made in the software it sounds like. Can you switch back or forth between sample rates, and subsequently the number of FIR taps?


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----------



## oliverlim

I have always set my output sample rate at 96khz. Should I be setting it to 48khz? 

I notice I can also set the recording sample rate. Default is 48khz. But 96khz is also a
Option. I tested it once and it seems to double the time taken to reach the same measurement points. Any benefits to recording at 48 or 96?





Raimonds said:


> Alextaastrup said:
> 
> 
> 
> Should we make new measurements with Workshop after apgrading the firmware for apl1?
> 
> Sendt fra min GT-I9505 med Tapatalk
> 
> 
> 
> No, you just need to set "96 kHz" as output filter sample rate and click "Calculate" for respective measurement in Workshop.
Click to expand...


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

SubterFUSE has a nice way to make inverse filters with smaart 
If someone wants the free way you can use rephase , click on compensate mode and draw the responce with the IIR eq and export the eqs as biquads (if you have minidsp) 
Otherwise you could write down the values from rephase and copy them into your dsp manually.

It's pretty sweet. Just be careful of inverse filters with adding boost. I would draw the responce at the bottom line on the frequency responce so it only cuts in the majority of the filter


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So, I'm at a show and don't have much time to check, but I think I mentioned that I'd be willing to drive to NC to help people learn their APL...

So here's the deal, I get home(TX) on the 19th, and will be home until the 7th. The bad news is that the Miata will go into the shop to repair the hail damage on the 20th and it could be there the entire time I'm home, they say it'll only be 9 days, but I don't trust that. So that doesn't leave me any time to travel with my car and APL.

However! When I hit the road again, I'll be going to Williamsburg, VA for two weeks, on 5/10-5/14 I could do one-on-one teaching sessions in the evening. I can do the same, in the same location, on 5/22-5/23. But you MUST bring your car to me, AND already have your APL1 installed and ready to tune. I'll have the software, laptop, and mic to tune with. Also, the bar just off the course is awesome and I'll buy the first round!

Also, are there any other APL owners in the country who have a unit and don't really know what they are doing? If so, speak up! My tour might be coming to your area!


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If you're in oregon. Id love to hear your car.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll be in Portland this summer, but I won't have my car with me. When I'm touring I'm driving a Peterbilt with a stock system that is so terrible I'd rather listen to headphones. 

I have family in Seattle, and might make it up there this winter wit the car...


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I'll be in Portland this summer, but I won't have my car with me. When I'm touring I'm driving a Peterbilt with a stock system that is so terrible I'd rather listen to headphones.
> 
> I have family in Seattle, and might make it up there this winter wit the car...


Well keep me informed. Ill prob have a ddrc24 by then. Maybe u can help me tune that 

Sent from my SGH-M919 using Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Jscoyne2 said:


> Well keep me informed. Ill prob have a ddrc24 by then. Maybe u can help me tune that
> 
> Sent from my SGH-M919 using Tapatalk


I'll be there from 9/24 - 10/5, just off Marine Drive. I haven't messed with the ddrc24, but it sounds like fun!


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I'll be there from 9/24 - 10/5, just off Marine Drive. I haven't messed with the ddrc24, but it sounds like fun!


Noted. See you then!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Also note, the tournament itself is 9/28 - 10/3, tournament days are incredibly LONG days for me, so I can't help or meet up at all on these dates. The rest of the dates are great for meeting up in the evenings.


----------



## Jscoyne2

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Also note, the tournament itself is 9/28 - 10/3, tournament days are incredibly LONG days for me, so I can't help or meet up at all on these dates. The rest of the dates are great for meeting up in the evenings.


No worries

Sent from my SGH-M919 using Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The same help in Europe/scandinavian countries. I can assist everybody in using apl in the best way.

Sendt fra min GT-I9505 med Tapatalk


----------



## subterFUSE

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Clay helped me tune my APL1 today. We did not have a lot of time but I just wanted to get a general idea for what it can do.

The improvement in tonality was impressive. Especially in the midbass and sub bass response. It made my bass sound louder and cleaner at the same time. 

We ran into 1 problem. Before taking the measurements we loaded my current competition tune into the Helix DSP Pro. Then we measured with APL Workshop and calculated the filters. We applied the filters to my APL1 and listened. The tonality improved but my center image got moved from perfect center to about 12 inches left of center with the APL1 activated.

Why would the APL make my center image move to the left? Did it measure my right side as being louder than the left and then overcompensate?


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----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

That's strange I don't remember having this problem, in fact I think I never had to modify my TA post APL.
Did you measure both seats per channel?
Do you use asymmetric crossover points?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Elgrosso is right. The reason is that apl attenuates the amount of acoustic power from both fronts to an equal value. Very precisely. It is difficult to achieve this result with another means. Now it is time to make new time alighnment, as out of two channels, that which located more closer to a listener, sounds more loud. Distance now begins to play a dominating role in moving the scene due to energy dissipation in the air.

Regarding tonality - it is the same now after the apl run. If you made some EQ before this with Helix DSP, you was not able to get it equal for these two channels. It means again - need for TA. By definition, it is not possible in practice to get the same results with a unit having 31 taps against 4096 availabe available for apl1. Corrected tonality in the first turn means less masking of sound by each other. That is why people are typically amased listening apl result for the first time.

Last, but not least - solving of minimum phase problems with the help of apl technology. Solving this results usually in better tonality, and as a result - need for new TA.

Sendt fra min GT-I9505 med Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So do I need to listen to the new APL tune and adjust the delay to move my center stage back into the correct location?

After that, do I measure with workshop again? Do I measure with the APL filters active or bypassed?

Claydo will attest that before applying the APL filters my tune in the Helix DSP was very good. After APL it was better in tonality but worse in soundstage and imaging.


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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Bypass is all switched off. So no meaning. It is enough just with one run of the apl test. Avoid bypass and make TA

Sendt fra min GT-I9505 med Tapatalk


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The left and right sides are measured independently, aren't they? Sorry I missed that when you guys were doing your thing with the mic. 


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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right, sepatately. But after apl run they must play exactly the same. You can repeat the test with uploaded filters in order to check how apl1 fits your target curve for both front channels. It is very helpfull to plot the result of the second test along with the target curve on the same plot.

Sendt fra min GT-I9505 med Tapatalk


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Right, sepatately. But after apl run they must play exactly the same. You can repeat the test with uploaded filters in order to check how apl1 fits your target curve for both front channels. It is very helpfull to plot the result of the second test along with the target curve on the same plot.
> 
> Sendt fra min GT-I9505 med Tapatalk



Sounds like then a good thing for the Helix DSP since you can link sets of drivers. So link left side then link right side, then set TA after the APL1 tune to center image. Crucial timing being done prior being down the sides.. Left tweeter to mid to midbass to sub. 


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----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

I was really impressed with what I heard this weekend in Clay's car with the different APL1 curves. Probably the best coherence from top down that I've heard in that car. Nothing stood out as an issue. Excellent tonality. 


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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks Scott! 

I had my best results setting up everything before the apl measurements. If you have any, I mean any errors before apl, the apl tune will make them stand out and smack you.....lol. So pre apl, you'd better have it right, or its not going to work. I wouldn't change anything after the apl corrections, but if the apl showed errors in my setup, I would simply recognize what it showed me with the sound, revisit that area with the apl in bypass, then run a new apl measurement with my dsp setup corrections already applied, but always measuring the system with the apl in bypass, so im measuring the basline dsp settings, and not previosly applied apl corrections. I feel that adjustments after the apl corrections taint it's "magic", and my testing confirmed this. So any miscues in your post apl corrections are typically manual setup mistakes in your dsp........


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Sounds like then a good thing for the Helix DSP since you can link sets of drivers. So link left side then link right side, then set TA after the APL1 tune to center image. Crucial timing being done prior being down the sides.. Left tweeter to mid to midbass to sub.
> 
> 
> Sent from my iPhone using Tapatalk Pro


Actually Raimonds suggested to make three consequent measurements with Workshop and average the results. It seems to be the most correct way of doing, but from my experience, if environment is not noisy, due to an excellent repeatibility, it might be good enough with one test per side comprising 150-200 sweeps. But again, do not forget to apply the calibration file for your mic. It is one of the most critical places here. You could use this calibratiob file later, not necessarily during the test, if you are not going to upload fir-filters immediately.

Regarding first impressions after everything is made correctly - IMPRESSED! I had the same feeling for 3 years ago, when my first apl1 started to make its magic. Still curios how it could be, that in 21st century people are surprised with a good quality sound! Thanks to Raimonds. I throw down all my previous DSP's and never regret...

One more thing - do not be lazy to check the quality of the in-built sound cards in laptops. Some of them are acceptable, some others not. I had some issues with the DELL laptop. Got very strange results, and could not find a reason to it untill I bought an external sound card. The same with microfon. Do not use fabric made callibration for "that" type of microfon. They are different as day and night. Use individual calibration if you want to get reasonable results. Some basic knowledge of measuring technique is appreciated here.

Sendt fra min T1-A21L med Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Guys..... I have a lot to add but don't have the time to type it up right now.


I took my car to a show this weekend and used the APL1 tune, but with some minor corrections that I made to fix the imaging problem.

I took 1st place in both of the formats, and several people that have known my car well all said I have the best tune in the car that I have ever had.

I have some pictures of the response in the car to share, also.... so we can see what the APL did and how I fixed it to get through my competition. I'm eventually hoping to understand what we did wrong to make the APL mess up my imaging so much, but that will have to wait until I have enough time to type a full report.

The bottom line is that my car does sound better than it ever has before, now that I have activated the APL1.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Congrats John! Apl for the win....lol. What did ya do, just correct the stage shift after the apl corrections? Well.....just remembered you stated you didn't have time to tell the whole story.......so it can wait....lol.

I'm glad you're liking the results tho......I love what it did in my car, and the ease of applying new curves over top of the correction files absolutely knocks it out of the park for me. I was hoping it would work out for ya in the audi, and when I heard what it did for your sub/midbass transition, I knew it was gonna be phenomenal once the staging was fixed. I hope you get to try what I sent you in pm, just out of curiosity if nothing else, because that path (as simple as it sounds) made my car sing like it never has.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oh....and I still believe once you get to messing around with it even more.......that multi-switch will get mounted!


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Looking around for what I can sell for the last bit of coin to put my order in. Lawn care? I can't part with my little JL 12TW1 but might have to. 


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----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

I will say from John's statement that delay steepens the phase response, if that's the correct appropriate terminology, I'm going to try different delay settings and play with incremental phase to see if I can make the subs and midbass have more "in-phase" bandwidth in their crossover region. Unfortunately no time to try this in room EQ wizard as it's not real time. 


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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It's a great unit Scott, I think it would improve anyone's sound.......


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> It's a great unit Scott, I think it would improve anyone's sound.......



Even mine right? LOL!!!!! But yeah what it's done for yours is amazing I have to admit. 


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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It fixed problems I fought for several years using conventional tools to no avail.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Guys, try TDA APL for optimisation of TA. Believe me, nothing is more evident in results. Delays could be made just within apl techology pack. If you use ConneqC1, you are not limited more to 10-15 msec like other DSP's. Mine is more than 50 msec now for the front channels. It was necessary to keep everything comming simultaniously to the listening point. 

Congratulations to subterFUSE. Great results.

Sendt fra min GT-I9505 med Tapatalk


----------



## truckerfte

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Looking around for what I can sell for the last bit of coin to put my order in. Lawn care? I can't part with my little JL 12TW1 but might have to.
> 
> 
> Sent from my iPhone using Tapatalk Pro



LOL, ive been reading and re reading this thread over the last couple of days, and im in the same boat...wondering how much of the stash i am willing to part with. Anyone want an ms8?


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Guys, try TDA APL for optimisation of TA. Believe me, nothing is more evident in results. Delays could be made just within apl techology pack. If you use ConneqC1, you are not limited more to 10-15 msec like other DSP's. Mine is more than 50 msec now for the front channels. It was necessary to keep everything comming simultaniously to the listening point.
> 
> Congratulations to subterFUSE. Great results.
> 
> Sendt fra min GT-I9505 med Tapatalk


I have TDA, and tried it a couple times with mixed results. I attribute the inconsistencies to the Operator (me), rather than the tool. I'm quite sure I certainly don't understand all that's going on in the software. TDA would be a very good candidate for in-depth youtube instructional video. I have no doubt that in the right hands, it can make alignment a very simple task. Reading over this doc again it's starting to make better sense.. The main measurement screen interface is where I got stuck last time though.. 
http://aplaudio.com/downloads/Introduction-to-TDA.pdf
http://aplaudio.com/downloads/TDA-Installation-and-Quick-Start-Guide.pdf


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It could not be a mess if you place the mic at exactly the same position. Software interface is easy to understand. The latest versions give you more detailed information. So, what's the problem? My suggestion is not to move a mic if you play with TA settings or optimizing subwoofet location. 

Sendt fra min GT-I9505 med Tapatalk


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> It could not be a mess if you place the mic at exactly the same position. Software interface is easy to understand. The latest versions give you more detailed information. So, what's the problem? My suggestion is not to move a mic if you play with TA settings or optimizing subwoofet location.
> 
> Sendt fra min GT-I9505 med Tapatalk



No problem really. Just need to practice with it. Mic for this would always be stationary at the headrest. And agreed, it's certainly easier than generating IR plots in Room EQ Wizard which requires a reference loop-back from the system or sound interface. And the visual plot it generates is by far easier to interpret, even for subwoofer timing which is sketchy at best if even possible with impulse response. 


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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Congrats John! Apl for the win....lol. What did ya do, just correct the stage shift after the apl corrections? Well.....just remembered you stated you didn't have time to tell the whole story.......so it can wait....lol.



The only changes I made was to the EQ in the Helix DSP. The APL1 messed up the EQ balance left to right side, so I just went into the Helix and quickly fixed it so that the left and right speakers were playing equal.

Once I did that, my center image was perfect. Left side and Right side images were also perfect, and moved outside of the pillars to the side mirrors.

The left-center and right-center images were OK, but they did move around based on frequency. I attribute this to the passive crossover between the tweeter and midrange drivers, and the lack of independent EQ on them.


I'll post measurements when I can find the time.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> ...
> The left-center and right-center images were OK, but they did move around based on frequency. I attribute this to the passive crossover between the tweeter and midrange drivers, and the lack of independent EQ on them.
> 
> 
> I'll post measurements when I can find the time.


I would think this is more due to the post APL EQ changes, it messed up the phase adjustments that the APL applied.
It's not a good habit to change again the pre-tune after APL, sure for quick test to mess around to get an idea but not for the final tune.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> It's not a good habit to change again the pre-tune after APL, sure for quick test to mess around to get an idea but not for the final tune.



This is kinda my thinking, I don't change anything post apl, although if post apl shows problems, I'll bypass the apl, make corrections, then remeasure. This method has proven very effective for me. If anything is out of order, and I mean ANYTHING, the apl tune will make it stick out like a sore thumb........


----------



## truckguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

When the apl works its magic does it lower your overall output or does it stay about the same? What kind of requirements does a laptop need to run the workshop software? I bought a very basic Dell laptop a while back just for tuning. When is the group buy happening for the software, apl, and 16 preset switch?!


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I would think this is more due to the post APL EQ changes, it messed up the phase adjustments that the APL applied.
> It's not a good habit to change again the pre-tune after APL, sure for quick test to mess around to get an idea but not for the final tune.


Well I had to do this because the APL tune was so messed up.

I will show measurements to prove this later.


It was probably a mistake in the measurement process with APL Workshop that caused the problems. But I had only 30 minutes to fix the issue and did what I knew how to do with that short amount of time.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Well I had to do this because the APL tune was so messed up.
> 
> I will show measurements to prove this later.
> 
> 
> It was probably a mistake in the measurement process with APL Workshop that caused the problems. But I had only 30 minutes to fix the issue and did what I knew how to do with that short amount of time.


And that says a lot the APL concept, you already won with a system that you think can still be improved!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> This is kinda my thinking, I don't change anything post apl, although if post apl shows problems, I'll bypass the apl, make corrections, then remeasure. This method has proven very effective for me. If anything is out of order, and I mean ANYTHING, the apl tune will make it stick out like a sore thumb........


Agree! bad pre-tune stuff comes out even more.

I must add, a non perfect tune will already gain a lot with it, no need to chase the perfect pre-tune first. 
But a bad one, like bad summing, wrong TA, beaming etc, then yes these issues will stand out even more. And they will become more visible on the SPFR measurements so easier to fix.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Well I had to do this because the APL tune was so messed up.
> 
> I will show measurements to prove this later.
> 
> 
> It was probably a mistake in the measurement process with APL Workshop that caused the problems. But I had only 30 minutes to fix the issue and did what I knew how to do with that short amount of time.


Hey, it was crunch time, you had to do what you had to do! That stage was pretty skewed last I heard it. So fine job getting it touched up in time for the show the next day!


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You guys are pointing out an issue I've seen with the APL1 and software. First, I haven't seen a prescriptive set of steps that should be performed to get a good tune. New people that buy the APL1 have to read through a huge thread and even then don't find clear, prescriptive instructions. It really shouldn't be this hard for a device that is purportedly easier to use than most DSPs. Second, the software packages shouldn't be separate, adds confusion, and I can't understand the value in having them separate. I think the hardware and software idea is great for the APL1 but if a few things were fixed, it really should be more popular than it is. And for a device that has been out this long, we should be talking about details of how to get a better tune or tweak it better, not "I'm not sure how to do this." I see potential in the APL1 but it has been frustrating watching it flounder when it shouldn't be but that is just my opinion. I'd like to point out that I have an APL1, two actually that I picked up from DIYMA members, but haven't had time to move my vehicle installs forward yet.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I will say, it isn't really a device for beginners......it is not an ms8, if you don't already have the skills necessary to make your system sing with a manual dsp, which is still required anyways, then the apl will be a disappointment to you. If, however you are an experienced tuner, and you know the time and difficulty that goes into a proper tune, this device is an amazing time saver, that just happens to use powerful tools and a proprietary measurement software that can fix things a typical dsp doesent have a chance at fixing. It also takes a bit of computer skill, but I'm living proof that that can be worked around. I'm not very good with computers in general, but there's enough info on this very thread, and the quick start guide to get ya there......


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I must add, a non perfect tune will already gain a lot with it, no need to chase the perfect pre-tune first.


My Miata is a good example of that.



dgage said:


> You guys are pointing out an issue I've seen with the APL1 and software. First, I haven't seen a prescriptive set of steps that should be performed to get a good tune. New people that buy the APL1 have to read through a huge thread and even then don't find clear, prescriptive instructions. It really shouldn't be this hard for a device that is purportedly easier to use than most DSPs. Second, the software packages shouldn't be separate, adds confusion, and I can't understand the value in having them separate. I think the hardware and software idea is great for the APL1 but if a few things were fixed, it really should be more popular than it is. And for a device that has been out this long, we should be talking about details of how to get a better tune or tweak it better, not "I'm not sure how to do this." I see potential in the APL1 but it has been frustrating watching it flounder when it shouldn't be but that is just my opinion. I'd like to point out that I have an APL1, two actually that I picked up from DIYMA members, but haven't had time to move my vehicle installs forward yet.


Part of my struggle with it was that I didn't have a system that was complete enough to actually use it. Before actually firing it up, it was pretty difficult to wrap my head around how it works.

If your cars aren't complete enough to start tuning with it, then it might be worth it to set one up in the home, if you have the gear for it. It has a steep learning curve to setup and learn. But once you get part those two steps, actually tuning is super easy and fast.

I've started a new step-by-step PDF for it, but progress will be slow as I have a ton of administrative stuff to catch up on with the tour. In the meantime, the guide I posted in this thread should get you started.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks Lumberman. I could use them in the house but don't have time for that either so they sit on a shelf until I can one day get to them. My rant really wasn't about me, I'm just a little surprised to continue to see these sorts of discussions with something that has been out as long as it has. If Raimonds or someone he paid (or anyone) put together the sort of step by step you mention, I think the APL1 could take off and show its power. And that means it should be linked to and documented on the official site, not buried on page 20(?) of a thread. But again, a rant for a product that I think could be great and would like to see it thrive better. Then again, I could say the same about my own business that I'm trying to take care of a myriad of details behind the scenes so I know it isn't necessarily easy but it is necessary for the requisite success to happen.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Guys I really feel like this thread is getting more obscure and obscure.
Just too many people talk about it, without having TRIED it once.
I don't understand, if I put one ground in something I wanna test it 
Everything is here, at least 90%, and the rest you'll learn yourself or get it from Raimonds directly. 
Start to play with the device like said LumbermanSVO.
If I was able to do it, everybody can do it, and I'm not joking, I'm pretty lazy and dumb.
Sure it could be better but at least try the first step! It won't kill your drivers, it's a DIY site or not?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

To be fair this is quite a complicated software to install and use. But then again the results it gets even if you spend 5 mins following the instructions blindly is fantastic! I cant imagine what I will end up as I continue to learn and tweak the tune and options.

On the other hand, the customer support response is FANTASTIC! I have to say I never had faster replies to my email questions in my life. Basically all questions are responded to the same day or next day latest. You will even get responses on most weekends. They even offer to do a remote desktop to help if you continue to have issues. 

It has come to a stage that I cannot imagine not having a APL1 in my car system. Listening to it in bypass is just wrong.

I for one am glad I persisted in getting this to work in my setup.





dgage said:


> You guys are pointing out an issue I've seen with the APL1 and software. First, I haven't seen a prescriptive set of steps that should be performed to get a good tune. New people that buy the APL1 have to read through a huge thread and even then don't find clear, prescriptive instructions. It really shouldn't be this hard for a device that is purportedly easier to use than most DSPs. Second, the software packages shouldn't be separate, adds confusion, and I can't understand the value in having them separate. I think the hardware and software idea is great for the APL1 but if a few things were fixed, it really should be more popular than it is. And for a device that has been out this long, we should be talking about details of how to get a better tune or tweak it better, not "I'm not sure how to do this." I see potential in the APL1 but it has been frustrating watching it flounder when it shouldn't be but that is just my opinion. I'd like to point out that I have an APL1, two actually that I picked up from DIYMA members, but haven't had time to move my vehicle installs forward yet.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Since I have no time, I'll bow out of this discussion as has been suggested. I'll just say that having kept up with this thread, I see a recurring theme of basic issues, which tells me something is missing. I'm excited about the capabilities I know are there from understanding the underlying and impressive technology. I see great potential but like I said, I'm out since I just have the hardware but no time to actually put it to use at this point in time. Wish you guys the best that have time to work with this incredible piece of equipment and software.

--David


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> To be fair this is quite a complicated software to install and use. But then again the results it gets even if you spend 5 mins following the instructions blindly is fantastic! I cant imagine what I will end up as I continue to learn and tweak the tune and options.
> 
> On the other hand, the customer support response is FANTASTIC! I have to say I never had faster replies to my email questions in my life. Basically all questions are responded to the same day or next day latest. You will even get responses on most weekends. They even offer to do a remote desktop to help if you continue to have issues.
> 
> It has come to a stage that I cannot imagine not having a APL1 in my car system. Listening to it in bypass is just wrong.
> 
> I for one am glad I persisted in getting this to work in my setup.



I have to agree with ya on this, Raimonds is always quick to respond, and great about answering questions! All my answers have come the same day as well, weekends included......


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> To be fair this is quite a complicated software to install and use. But then again the results it gets even if you spend 5 mins following the instructions blindly is fantastic! I cant imagine what I will end up as I continue to learn and tweak the tune and options.
> 
> On the other hand, the customer support response is FANTASTIC! I have to say I never had faster replies to my email questions in my life. Basically all questions are responded to the same day or next day latest. You will even get responses on most weekends. They even offer to do a remote desktop to help if you continue to have issues.
> 
> It has come to a stage that I cannot imagine not having a APL1 in my car system. Listening to it in bypass is just wrong.
> 
> I for one am glad I persisted in getting this to work in my setup.



I have to agree here, Raimonds customer support is spectacular, with email responses always being rapid, and yer right, weekends as well! I too can't imagine my system at this point without an apl in the mix, it's definitely secured a spot in my car stereo world as vital.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> It could not be a mess if you place the mic at exactly the same position. Software interface is easy to understand. The latest versions give you more detailed information. So, what's the problem? My suggestion is not to move a mic if you play with TA settings or optimizing subwoofet location.
> 
> Sendt fra min GT-I9505 med Tapatalk


Now that I finally got APL1 installed and working fine with a few tunes that I like. I would like to start working on TDA. Is this the right way to go about it?

1. Run TDA without APL or APL in bypass. 

2. Get all drivers as close as possible in TA/Group delay. 

3. Do APL tune. 

4. Rerun TDA to see what the TA/GD looks like.

5. Make changes to TA using your DSP to see if you can get it aligned even better? 

In my case I do not have a sub. Just a 3 ways active.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> Thanks Lumberman. I could use them in the house but don't have time for that either so they sit on a shelf until I can one day get to them. My rant really wasn't about me, I'm just a little surprised to continue to see these sorts of discussions with something that has been out as long as it has. If Raimonds or someone he paid (or anyone) put together the sort of step by step you mention, I think the APL1 could take off and show its power. And that means it should be linked to and documented on the official site, not buried on page 20(?) of a thread. But again, a rant for a product that I think could be great and would like to see it thrive better. Then again, I could say the same about my own business that I'm trying to take care of a myriad of details behind the scenes so I know it isn't necessarily easy but it is necessary for the requisite success to happen.


Honestly, I wanted to make a similar rant for awhile. I'd read this whole thread, and all the other APL threads, multiple times. I had the software and hardware, but it was still confusing. It wasn't until I actually had the APL1 in the signal chain that it started making sense. From there I only had a few more questions and I was comfortable enough to get a good tune. Once I heard the difference it made, I knew I had to make some sort of tutorial.

So hang in there, and feel free to ask questions when you finally have the time to tinker with it.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Honestly, I wanted to make a similar rant for awhile. I'd read this whole thread, and all the other APL threads, multiple times. I had the software and hardware, but it was still confusing. It wasn't until I actually had the APL1 in the signal chain that it started making sense. From there I only had a few more questions and I was comfortable enough to get a good tune. Once I heard the difference it made, I knew I had to make some sort of tutorial.
> 
> So hang in there, and feel free to ask questions when you finally have the time to tinker with it.


Great to hear. And I'm not trying to be negative although I am, it is in my nature. I'm a consultant but even when I came out of school, I would look at something and start tearing it apart. For a while I just thought I was negative but I soon learned it was in my nature to look for problems and ways to solve them. So really, I'm not bashing or anything like that, I just see great potential in Raimond's hardware and software and hope that it is realized. I look forward to your tutorial but I'm so busy right now, I wish I had time to think about using it.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dgage said:


> You guys are pointing out an issue I've seen with the APL1 and software. First, I haven't seen a prescriptive set of steps that should be performed to get a good tune. New people that buy the APL1 have to read through a huge thread and even then don't find clear, prescriptive instructions. It really shouldn't be this hard for a device that is purportedly easier to use than most DSPs. Second, the software packages shouldn't be separate, adds confusion, and I can't understand the value in having them separate. I think the hardware and software idea is great for the APL1 but if a few things were fixed, it really should be more popular than it is. And for a device that has been out this long, we should be talking about details of how to get a better tune or tweak it better, not "I'm not sure how to do this." I see potential in the APL1 but it has been frustrating watching it flounder when it shouldn't be but that is just my opinion. I'd like to point out that I have an APL1, two actually that I picked up from DIYMA members, but haven't had time to move my vehicle installs forward yet.


The main reason that software package is sold separately is that the whole concept was intended to be used by tuning workshops. One set of the software should be bought for themselfes, hardware boxes (apl1) - for their custommers. On the other hand, the apl technology could be used for carPC or other systems based on Windows and Android. In these cases hardware is not needed. One can use more cheap vst plugin or irs-files for the convolver. 

Sendt fra min GT-I9505 med Tapatalk


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ok. Here are my Left speaker only, TDA plot, GDR, DFR with apl in bypass and apl tune. The plots for some reasons does not seem to have improved much. But the sound is pretty fantastic. It sounds like I have added a subwoofer. Mid bass punch is great. Tonality esp guitars strums and plucks is just crazily good. 

However, I am still not seeing why it does not seem to be improving my plots much. I would have thought that it would show much after with the tune in place. Any ideas?

Also let me know if I can further improve my TA with APL in bypass. 

Thanks!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nice, the tda plot seems much cleaner on midbass.
Where do you cross everything? And did you spend some time on your Ta with TdA before the APL? You can use a shorter scale like 5 or 10ms total to get a precise view.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It seems that you ought to do more precise TA before apl run. The graphs show that a little delay of midbass compared to the tweeter might be needed, but down to appr. 500 Hz is not so critical for a human far if it is less 2 msec. 

Sendt fra min GT-I9505 med Tapatalk


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Nice, the tda plot seems much cleaner on midbass.
> Where do you cross everything? And did you spend some time on your Ta with TdA before the APL? You can use a shorter scale like 5 or 10ms total to get a precise view.


My crossovers are 250hz for my woofers, 250hz and 3500hz for my mids and 3500hz for my tweeters. I did TA for my system with APL in bypass. Raimonds, did tell me LR24 would have a 0.14ms delay on my mids and 2ms for my woofercompared to my tweeter. So I guess I could improve a little on my mids by reducing around 2ms delay.




Alextaastrup said:


> It seems that you ought to do more precise TA before apl run. The graphs show that a little delay of midbass compared to the tweeter might be needed, but down to appr. 500 Hz is not so critical for a human far if it is less 2 msec.
> 
> Sendt fra min GT-I9505 med Tapatalk


When you say delay of midbass. Do you mean the mid bass needs to be a little more delayed? Mid bass as in the woofer?


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So am I understanding correct you need to buy the apl-1 and the software?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dcfis said:


> So am I understanding correct you need to buy the apl-1 and the software?



If you have a android base Head unit or play your music from a android player, you would only need to get the software.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> My crossovers are 250hz for my woofers, 250hz and 3500hz for my mids and 3500hz for my tweeters. I did TA for my system with APL in bypass. Raimonds, did tell me LR24 would have a 0.14ms delay on my mids and 2ms for my woofercompared to my tweeter. So I guess I could improve a little on my mids by reducing around 2ms delay.
> 
> 
> 
> 
> When you say delay of midbass. Do you mean the mid bass needs to be a little more delayed? Mid bass as in the woofer?


I did not know that you have 3-way system. It seems that a sound from the tweeter comming earlier that from your mid. 2 msec less delay for a mid would be fine as a starting point. You definitely have some problems between 150-510 Hz. Could be of a modal character due to placement and orientation of the loudspeakers. Can you show afr graph? Do you have peaks at the same frequencies on the amplitude plot?

Ideally your dfr curve should be as close to gdr as possible, as I undesrstood it correct.

Sendt fra min T1-A21L med Tapatalk


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi Friends,

I must explain Oliver`s case:



oliverlim said:


> Ok. Here are my Left speaker only, TDA plot, GDR, DFR with apl in bypass and apl tune. ....
> ....
> Also let me know if I can further improve my TA with APL in bypass.
> 
> Thanks!


The IR and TDA image is highly disturbed by pretty large distance from loudspeakers and they directivity side lobes. That is causing situation when reflected side lobes are stronger then direct sound and they are causing some kind of mess in IR and TDA image. This mess can not be improved by any kind of electronics. It can be improved only by change of drivers and its placement much closely to a listener (mic).
Same time, it is possible to find better place for mic just by changing its place by few centimeters to improve TDA image for particular measurement and make it more usable for time alignment.
You must use GDR with "subtract minimum phase" and try to see the earliest undisturbed parts of GDR. It requires some skills.
You must take into account that particular time alignment is just for one mic placement(listening position) also, for car environment where loudspeakers of "ways" are placed in different positions.
It is almost impossible to see the timing improvement of APL`s equalizer work in such "mess" also.


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If it works on android how does MECA check stock class competitors if they are using the software or for that matter since the competitors can provide their own digital files they arent using that music manipulator software?


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It is not a manipulator. It is sound reproduktion improver, which every manufactorer of OEM Hu must have in their basic setups. It is a killer for DSP market, as I can see. Thats why so high resistance from this industry. 

Sendt fra min GT-I9505 med Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi Friends,
> 
> I must explain Oliver`s case:
> 
> 
> 
> The IR and TDA image is highly disturbed by pretty large distance from loudspeakers and they directivity side lobes. That is causing situation when reflected side lobes are stronger then direct sound and they are causing some kind of mess in IR and TDA image. This mess can not be improved by any kind of electronics. It can be improved only by change of drivers and its placement much closely to a listener (mic).
> Same time, it is possible to find better place for mic just by changing its place by few centimeters to improve TDA image for particular measurement and make it more usable for time alignment.
> You must use GDR with "subtract minimum phase" and try to see the earliest undisturbed parts of GDR. It requires some skills.
> You must take into account that particular time alignment is just for one mic placement(listening position) also, for car environment where loudspeakers of "ways" are placed in different positions.
> It is almost impossible to see the timing improvement of APL`s equalizer work in such "mess" also.


I might admit that Rajmonds is precise in his explanations, as usual. 

But this is exactly what I wanted to say - by minimasing reflections on the path from the source to a listener position, you will increase the effect of apl. Modal problems could not be solved with the help of EQ. 

Sendt fra min GT-I9505 med Tapatalk


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi Raimonds,

So this means my TA is about as good as I can get with this current speaker position and speakers? 

Although by looking at my TDA, it does seem like I can decrease my mids and woofers delay by about 2ms each and then redoing my apl measurements. 






Raimonds said:


> Hi Friends,
> 
> I must explain Oliver`s case:
> 
> 
> 
> The IR and TDA image is highly disturbed by pretty large distance from loudspeakers and they directivity side lobes. That is causing situation when reflected side lobes are stronger then direct sound and they are causing some kind of mess in IR and TDA image. This mess can not be improved by any kind of electronics. It can be improved only by change of drivers and its placement much closely to a listener (mic).
> Same time, it is possible to find better place for mic just by changing its place by few centimeters to improve TDA image for particular measurement and make it more usable for time alignment.
> You must use GDR with "subtract minimum phase" and try to see the earliest undisturbed parts of GDR. It requires some skills.
> You must take into account that particular time alignment is just for one mic placement(listening position) also, for car environment where loudspeakers of "ways" are placed in different positions.
> It is almost impossible to see the timing improvement of APL`s equalizer work in such "mess" also.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

First picture: Here are my 2d graph for both sides (left and right - shown on the same graph). Measured simultaniously - there is an option for this in TDA APL. 3-way passive, where mid and tweeters are on the dash with 15 deegrees off-axe. Subwoofer in the trunk. The woofers are in the front​ doors. You could see some ta problems coursed by this at appr. 500 Hz. On the second graph - another settings for TA, but with the same placement of the front loudspeakers. Shown just as an example for improvement possibilities even with the passive setup.
















Sendt fra min T1-A21L med Tapatalk


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

This looks pretty amazing. I guess partly as the tweeter and mids are on the dash with no blockage. My Mids are at the door panel just below the tweeter. However, there is a handle just infront of the mid driver. Not sure what BMW was thinking about that handle/speaker position. But that could be the reason for the poor graph that I am seeing. 





Alextaastrup said:


> First picture: Here are my 2d graph for both sides (left and right - shown on the same graph). Measured simultaniously - there is an option for this in TDA APL. 3-way passive, where mid and tweeters are on the dash with 15 deegrees off-axe. Subwoofer in the trunk. The woofers are in the front​ doors. You could see some ta problems coursed by this at appr. 500 Hz. On the second graph - another settings for TA, but with the same placement of the front loudspeakers. Shown just as an example for improvement possibilities even with the passive setup.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Sendt fra min T1-A21L med Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> This looks pretty amazing. I guess partly as the tweeter and mids are on the dash with no blockage. My Mids are at the door panel just below the tweeter. However, there is a handle just infront of the mid driver. Not sure what BMW was thinking about that handle/speaker position. But that could be the reason for the poor graph that I am seeing.


Yes they look pretty smooth, with the big scale here needed for the sub delay.
But the highs won't look as smooth with the regular 30ms scale of course.
It’s a great tool to adjust, especially the low end since it’s super obvious, but don't focus too much on the smoothest graph. 
It's easy to get it ultra clean for one side/one point, but it's only one so really not that important (unless you hear with your nose ).


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right. Below 1,5 msec it is not audible, at least for majority. At least what science says. But again - on these graphs both sides are shown. And this is a reason for a fantastic scene.

Sendt fra min GT-I9505 med Tapatalk


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## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> So, I'm at a show and don't have much time to check, but I think I mentioned that I'd be willing to drive to NC to help people learn their APL...
> 
> So here's the deal, I get home(TX) on the 19th, and will be home until the 7th. The bad news is that the Miata will go into the shop to repair the hail damage on the 20th and it could be there the entire time I'm home, they say it'll only be 9 days, but I don't trust that. So that doesn't leave me any time to travel with my car and APL.
> 
> However! When I hit the road again, I'll be going to Williamsburg, VA for two weeks, on 5/10-5/14 I could do one-on-one teaching sessions in the evening. I can do the same, in the same location, on 5/22-5/23. But you MUST bring your car to me, AND already have your APL1 installed and ready to tune. I'll have the software, laptop, and mic to tune with. Also, the bar just off the course is awesome and I'll buy the first round!
> 
> Also, are there any other APL owners in the country who have a unit and don't really know what they are doing? If so, speak up! My tour might be coming to your area!



I'd be interested in learning about it. I'm up in PA, but could come down to VA if that works.


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

After VA I'll be in Atlantic City for two weeks, that might be closer. I'll also be in Toledo and Indy this year.

Just to be clear, I won't have my car or APL unit with me, so you'll need to bring yours, preferable installed in a car, at least temporarily. I travel the country in a big Peterbilt, so no custom audio gear.

I am buying another APL1 from a DIYMA member for my Bronco. If you guys want, I'll travel with it and make a temporary install in the Peterbilt for training purposes. But once it's time to go in the Bronco, it goes in the Bronco for good.


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## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> After VA I'll be in Atlantic City for two weeks, that might be closer. I'll also be in Toledo and Indy this year.
> 
> Just to be clear, I won't have my car or APL unit with me, so you'll need to bring yours, preferable installed in a car, at least temporarily. I travel the country in a big Peterbilt, so no custom audio gear.
> 
> I am buying another APL1 from a DIYMA member for my Bronco. If you guys want, I'll travel with it and make a temporary install in the Peterbilt for training purposes. But once it's time to go in the Bronco, it goes in the Bronco for good.


Maybe ill get one and meet up with you in AC

Sent from my VS988 using Tapatalk


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## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I could absolutely do Atlantic City. If you're wiling, lets set up a date to get together to go over it.

I will have the APL1 unit in, but if you have a vehicle with one in temporarily for training, that works great too.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I'd be interested in learning about it. I'm up in PA, but could come down to VA if that works.


I might come up to Williamsburg with the Audi if you came down, Steve. Bring the golf clubs, even.


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I might come up to Williamsburg with the Audi if you came down, Steve. Bring the golf clubs, even.



Awe now that's too many bad bad habits in one place. Car audio. Golf. What's next? Got it.. You need a bad motorcycle fetish to throw in. 


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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Awe now that's too many bad bad habits in one place. Car audio. Golf. What's next? Got it.. You need a bad motorcycle fetish to throw in.
> 
> 
> Sent from my iPhone using Tapatalk Pro




No motorcycles. My brother has a Ducati Street Fighter S.
But I ain't riding that thing. Yikes.


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----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll have at least one day off in AC, I'll know more tomorrow and get back to you!


----------



## I800C0LLECT

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I live in Williamsburg! Mind if I stop in to listen to some APL goodness?

Sent from my Pixel XL using Tapatalk


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In Williamgsburg, VA I *should* have the afternoon of 5/13 off, at the very least, I will have that evening off. I'll be working and staying at the Kingsmill Resort. 

In Atlantic City I *WILL* have 5/25 off and *should* have the afternoon of 5/28 off. I'll actually be working and staying at the Seaview Resort in Galloway, NJ.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> In Williamgsburg, VA I *should* have the afternoon of 5/13 off, at the very least, I will have that evening off. I'll be working and staying at the Kingsmill Resort.
> 
> 
> 
> In Atlantic City I *WILL* have 5/25 off and *should* have the afternoon of 5/28 off. I'll actually be working and staying at the Seaview Resort in Galloway, NJ.




5/13 works for me. I could play golf in the morning and tune in the afternoon or evening.

Can buy you dinner or beers after, too. 


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----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Th 13th it is then! There is a little bar just by the course called The Sportsman, it's a great place to grab a brew.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'll put that date in my calendar as well. 5/13 it is 

I'm a lousy golfer John (Don't get enough time to play), but I do enjoy playing. If it works time wise, I'll let you know if I'm able to join you.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Awesome!


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I'll put that date in my calendar as well. 5/13 it is
> 
> I'm a lousy golfer John (Don't get enough time to play), but I do enjoy playing. If it works time wise, I'll let you know if I'm able to join you.



I'll book a tee time in the morning just to be safe.

I'm just starting to get back into golf myself.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I booked a hotel room at the Colonial Williamsburg resort. We will be able to play the Golden Horseshoe Golf Club since I'll be a resort guest.

The Gold Course is closed until July. 

But the Green Course will be open and it's awesome. Rees Jones design. I'll have a tee time reserved for the morning of the 13th. Can always cancel later if necessary.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I wish I be there with all of you, guys. But the distance... God luck! 

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----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I got my second APL1, yay! 

If you want, we can throw it in the loop of your setup so you can hear the difference it makes in your actual system. If you don't have easy access to your RCA's, then maybe an AUX input?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I got my second APL1, yay!
> 
> If you want, we can throw it in the loop of your setup so you can hear the difference it makes in your actual system. If you don't have easy access to your RCA's, then maybe an AUX input?



Not sure I catch your drift?

I already have an APL1 installed. Are you saying test out a second one?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I'll put that date in my calendar as well. 5/13 it is
> 
> I'm a lousy golfer John (Don't get enough time to play), but I do enjoy playing. If it works time wise, I'll let you know if I'm able to join you.


10:00 AM tee time at Golden Horseshoe - Green course is reserved. My treat.


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Where is everyone buying those APL-1? Also thanks to Lumbermansvo for offering to help. I contacted him by email and he couldnt have been a more generous guy. Hope to meet him sometime when I got everything in


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Also, my car has balanced diff outputs. Does the APL1 accept these? Some kinda XLR connector?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Not sure I catch your drift?
> 
> I already have an APL1 installed. Are you saying test out a second one?


I should have clarified, "For those who don't have one yet" 



dcfis said:


> Also, my car has balanced diff outputs. Does the APL1 accept these? Some kinda XLR connector?


Does it have three legs for each channel? Ground, +, and - ? If so, that should be pretty easy to adapt to XLR, and Raimonds makes a unit with XLR connectors. If you just have Ground and +, then you should be fine with the RCA model.

Also, you buy them direct from Raimonds at Acoustic Power Lab :: Home or you might be able to pick up a used one in the classifieds, but don't count on that.


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have a +,-,and shield. 

OK so the APL-1 unit by itself will be all that I need? or is the 270 Euro software needed also?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You need the hardware and the "Workshop" software.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I want to learn how to do the advanced FIR filter time alignment stuff by frequency.


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----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I need to learn more about that too. I know you can export file from TDA and into Workshop, but I haven't massed with that yet.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I finally played with the Workshop software today and imported some FIR filters into Foobar2000 VST plugin to sample. It ended up being very bass heavy. I think I need to figure out the best way to do the actual measurements. I used one of my own basic target response files as a "T" correction in the measurement section.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> 10:00 AM tee time at Golden Horseshoe - Green course is reserved. My treat.


Very kind of you John! I'm looking forward to hacking my way through with you


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I finally played with the Workshop software today and imported some FIR filters into Foobar2000 VST plugin to sample. It ended up being very bass heavy. I think I need to figure out the best way to do the actual measurements. I used one of my own basic target response files as a "T" correction in the measurement section.


I really like the Andy/JBL curve, but with a big dip around 3k. It sounds natural and not fatiguing at all.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Very kind of you John!


FYI, my name is John too!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I want to learn how to do the advanced FIR filter time alignment stuff by frequency.
> 
> 
> Sent from my iPhone using Tapatalk


It seems not possible to make TA by frequency. One delay per channel. That is why on my graphs there are some small shifts in time domain (although rather acceptable due to psychoscoustics). I run 3 way passive. U should have apl-3 for 6 channels to do it. But agsin, do not expact frequency dependant time alignment. It would be nice to follow the group delay curve, but...

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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oh. My mistake. I thought that FIR filters could do varying time delay on different frequencies in order to cure group delay?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I finally played with the Workshop software today and imported some FIR filters into Foobar2000 VST plugin to sample. It ended up being very bass heavy. I think I need to figure out the best way to do the actual measurements. I used one of my own basic target response files as a "T" correction in the measurement section.


Regarding the target curve - everyone is welcome to use his own. I have compared MP1 from Raimonds with the optimal curve for loudspeakers designed by famous Danish company called Bruel&Kjer. They are almost sumilar except the region about 3kHz. But you need a ceetain headroom to correct your speakers. They should be at the first - full range. Small pc speakers do not fit here. More over, your preferencies in music. If you like more details in the midrange, then mp1 is not for you. Statistics says that good quality competition cars have typically 3-7dB less than tuned for ordinary public.

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

To delay FIR filters you can use ConneqC1.

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Regarding the target curve - everyone is welcome to use his own. I have compared MP1 from Raimonds with the optimal curve for loudspeakers designed by famous Danish company called Bruel&Kjer. They are almost sumilar except the region about 3kHz. But you need a ceetain headroom to correct your speakers. They should be at the first - full range. Small pc speakers do not fit here. More over, your preferencies in music. If you like more details in the midrange, then mp1 is not for you. Statistics says that good quality competition cars have typically 3-7dB less than tuned for ordinary public.
> 
> Sendt fra min GT-I9505 med Tapatalk


I mean bellow the trigger frequency of the cabin transfer function. 

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----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yeah I tried the MP1 first, but that one was too muddy and bass heavy too. Again though, this could be that I'm sort of "guessing" at the proper way to measure the vehicle in Workshop so not getting good results... A video showing the proper measurement technique would benefit us greatly. Also a screenshot of settings you are using when measuring.

Here is my screenshot of the APL Workshop configuration screens.




For some reason, when I browse for my mic cal file and click ok, it won't show up in the compensations and targets area like my target curve does. I have both a .frd version and a simple .txt version of the correction file but it doesn't load it in...any ideas there? 

John K- Since we use the same mic interface, I assume I must also check the "Enable ASIO" in the options screen, yes?

And then do we need to click the "Generate Linear Phase Filter" check box? I didn't do this for my first measurements and test and that could be part of the problem. 


Next, on the project screen it shows "composite correction". I assume this is used to average measurements together to form a correction file based on those averages...is that correct and does it take all of the measurements in the window or are they selectable. For example, if I've taken 3 left side measurements and 4 right side, can I choose which ones to average?



Thanks gents.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It should be possible to select

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Try to move your mic calibration file to the firectory, where the target curves are stored. Txt format should work fine. 

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----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I gave that a shot and same thing. I can see the file when I browse for it, I click ok and it doesn't appear in the list of corrections.


I tried to attach the mic cal txt file, but the forum limits text files to like 25kb ?? 

Here is it, broken into two text files. The first is from 5hz to 9.9khz. The second one is from 10khz-25khz. If you copy and paste them together you'll have my mic cal file. Maybe it works for you, or maybe you find the same thing?

Or is there a frequency limit for cal files? Like only between 20hz-20khz? Or only 1/3rd octave resolution points for correction?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Oh. My mistake. I thought that FIR filters could do varying time delay on different frequencies in order to cure group delay?


I like this idea. Let us share it with Raimonds. Maybe it is not so difficult to do, I really do not know. Anyway, apl soft allows to make unlimited TA in a car opposite to other DSP's that have max 0-15 msec spand.

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I gave that a shot and same thing. I can see the file when I browse for it, I click ok and it doesn't appear in the list of corrections.
> 
> 
> I tried to attach the mic cal txt file, but the forum limits text files to like 25kb ??
> 
> Here is it, broken into two text files. The first is from 5hz to 9.9khz. The second one is from 10khz-25khz. If you copy and paste them together you'll have my mic cal file. Maybe it works for you, or maybe you find the same thing?
> 
> Or is there a frequency limit for cal files? Like only between 20hz-20khz? Or only 1/3rd octave resolution points for correction?


Mine I have calibrated by myself. Raimonds did not suggest to use it below 1kHz as it is not easy to correct interferance problems of the surroundings. So how it looks like - just zero correction below that level. 

Why would you use a linear phase filter function? I suppose that default is a minimum phase... correct me if I am wrong.

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----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Yeah I tried the MP1 first, but that one was too muddy and bass heavy too. Again though, this could be that I'm sort of "guessing" at the proper way to measure the vehicle in Workshop so not getting good results... A video showing the proper measurement technique would benefit us greatly. Also a screenshot of settings you are using when measuring.
> 
> Here is my screenshot of the APL Workshop configuration screens.
> 
> 
> 
> 
> For some reason, when I browse for my mic cal file and click ok, it won't show up in the compensations and targets area like my target curve does. I have both a .frd version and a simple .txt version of the correction file but it doesn't load it in...any ideas there?
> 
> John K- Since we use the same mic interface, I assume I must also check the "Enable ASIO" in the options screen, yes?
> 
> And then do we need to click the "Generate Linear Phase Filter" check box? I didn't do this for my first measurements and test and that could be part of the problem.
> 
> 
> Next, on the project screen it shows "composite correction". I assume this is used to average measurements together to form a correction file based on those averages...is that correct and does it take all of the measurements in the window or are they selectable. For example, if I've taken 3 left side measurements and 4 right side, can I choose which ones to average?
> 
> 
> 
> Thanks gents.




I had the exact same impression for the first time with mp1, but now it's my go to curve.
What did you use before? You'll probably find yourself tuning differently pre-APL now.
I mean it's not only another tool to better adjust to your target like before, but it will change your goal as well.
The power response reading, the better sub/midbass integration etc made me adjust everything to a more gentle/smoother slope like mp1 compare to JBL. (with or without the 3.2K dip)
Anyway, not important for now.

The mic calibration file should go in the same APL folder with other txt files, like targets, compensation etc
I remember it was a bit hard to import mine (umik), I think I had to edit my text file, like removing some space and the 0 at the end or something like that. Try to open one of the default txt file in APL/data/CR, any target they're all the same format, and adapt your file to this format?
My mic is USB so I don't know about ASIO.
For the settings, if I remember:
generate linear phase filter > I never unchecked this one
Skip X impulse response > handy when the laptop is not accessible during sweeps
time window file > the first number is the time window for the impulse. This will mostly depend of your sub reponse (we have several example at the begining of this thread). I mostly used 50ms
Low/high freq limiter > not sure but I think it was the the max boost for low/high FR
EQ zero level > define the target level (compared to average of your total FR)
Composite correction > after clic you should have a window to select them


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

A limiter in the Workshop is limited to max 15 or maybe 20dB. If you have to correct more in order to fit your desired target curve - please check placement of the loudspeakers, X-over points or even replace them with better ones. Workshop simply gives you an indication that it is somerthing wrong with your hardware.

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> I gave that a shot and same thing. I can see the file when I browse for it, I click ok and it doesn't appear in the list of corrections.
> 
> 
> I tried to attach the mic cal txt file, but the forum limits text files to like 25kb ??
> 
> Here is it, broken into two text files. The first is from 5hz to 9.9khz. The second one is from 10khz-25khz. If you copy and paste them together you'll have my mic cal file. Maybe it works for you, or maybe you find the same thing?
> 
> Or is there a frequency limit for cal files? Like only between 20hz-20khz? Or only 1/3rd octave resolution points for correction?


I will check your files later. What about european/american formatting with comma and dots as separators? Should it be a reason?

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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hey Steve, I had the exact same problem with my mic calibration file not being recognizable to the workshop software, it's a simple formating issue that Raimonds fixed for me. Raimonds is tremendously helpful, and responsive via email, and simply asked me to send him my correction file, and he converted it to the correct format. Hit him up, he offers great support. I initiated our many email conversations via pm here on diyma.

As far as mp1 goes, it's a fine curve for getting started with hearing the correction magic, but once I got over how much better my "corrected" response was with the apl1, my personal preferences lead me to create my own target curves. I ended up on a "brighter" sound than mp1 that brought out more detail in the mid to top end, with a less "forward" upper midbass.......


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Great. What is really magic with the MP1 curve is a balance of acoustic power which leads to great deepnees in scene. Try to focus on this and compare your own target curve with MP1.

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----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Great. What is really magic with the MP1 curve is a balance of acoustic power which leads to great deepnees in scene. Try to focus on this and compare your own target curve with MP1.
> 
> Sendt fra min GT-I9505 med Tapatalk


Oh, no denying it is a fine curve, fo sho.........and yes with the multi switch unit I have done many comparisons between the growing batch of personal curves, and all the presets available in the unit, I've had a lot of fun with it! In the end tho, I still prefer the enhanced midrange detail of my personal curve......tonality is really just individual preference. This is still one of my favorite parts about the apl1.......the ability to quickly overlay your tonality/target curve over top of the corrections, it's so simple and quick, it's very addictive! I've never had the ability to so quickly change my tonality without affecting my response corrections, total game changer right there!


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## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just email your mic cal file to Raimonds and ask him to format it 


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----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I been experimenting a few curves as well. Mainly based on the Andy/JBL curve which I found too hash for long listening. 

Could you share yours here? Thanks.




claydo said:


> Hey Steve, I had the exact same problem with my mic calibration file not being recognizable to the workshop software, it's a simple formating issue that Raimonds fixed for me. Raimonds is tremendously helpful, and responsive via email, and simply asked me to send him my correction file, and he converted it to the correct format. Hit him up, he offers great support. I initiated our many email conversations via pm here on diyma.
> 
> As far as mp1 goes, it's a fine curve for getting started with hearing the correction magic, but once I got over how much better my "corrected" response was with the apl1, my personal preferences lead me to create my own target curves. I ended up on a "brighter" sound than mp1 that brought out more detail in the mid to top end, with a less "forward" upper midbass.......


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right now, I'm kinda diggin this one.....


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Right now, I'm kinda diggin this one.....


Would you be kind enough to attach the curve text file?


----------



## subterFUSE

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I need to learn more about that too. I know you can export file from TDA and into Workshop, but I haven't massed with that yet.




Is the filter export feature from TDA or from TDA EQ?

I think they are separate softwares.


Sent from my iPhone using Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Is the filter export feature from TDA or from TDA EQ?
> 
> I think they are separate softwares.
> 
> 
> Sent from my iPhone using Tapatalk


You are right. Workshop and TDA are different software and can not substitute each other. They also have different measurement technics, as for TDA there should measured at one point (listnening position).


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----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was talking about TDA vs TDA EQ


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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Right now, I'm kinda diggin this one.....


Great curve. But why you have an increase in amplitude at the frequencies above 30kHz? Is it audible? Would it be better to press this region down -20DB? 

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----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> I was talking about TDA vs TDA EQ
> 
> 
> Sent from my iPhone using Tapatalk


Sorry for misunderstanding. No idea. Don't use TDA EQ.


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----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Oh. My mistake. I thought that FIR filters could do varying time delay on different frequencies in order to cure group delay?


You thought right! This option is ready in prototype software.
But we must turn to such timing correction only after AFR correction is completely done.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Great curve. But why you have an increase in amplitude at the frequencies above 30kHz? Is it audible? Would it be better to press this region down -20DB?
> 
> Sendt fra min GT-I9505 med Tapatalk


Thanks! Audible, not to me lol, the dog may not like it if he goes for a ride.......my last adjustment is a broad cut centered at 22k, what you see is simply the curve rising back to zero......

Oliverlim, I don't know how to attach the text file here......sorry.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Dear friends,
Please feel free to send me incompatible correction files.
I will edit them!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just for everybody's information. At EMMA Eurofinals Mr. Dubinin (team Morel, Russia) has won 2 first places in march 2017: SQ X-cat unlimited one class and MM X-cat one class. Both with the help of APL technology. 

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----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I need to contact Raimonds...all of my APL software is on a laptop that I will never see again due to divorce issues.

Sorry Raimonds, been a tough few months...and leaving with nothing.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello captainobvious, PM me your mail and I will send you your corrected mic file. Should work now. Send to [email protected]

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----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Alex- thank you. Raimonds has sent me the corrected file. That was quick! 

I'll test it later today.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Alex- thank you. Raimonds has sent me the corrected file. That was quick!
> 
> I'll test it later today.


Yeah, Raimonds support is unbelievable. With your calibration file you will feel less amplitude in the range 500-15000Hz and some increase at the frequencies above 18kHz. Both appr. 2-3 DB. Hope this is an individual calibration, but not a generic one.









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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> You thought right! This option is ready in prototype software.
> But we must turn to such timing correction only after AFR correction is completely done.


I'd love to hear more about this!


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Yeah, Raimonds support is unbelievable. With your calibration file you will feel less amplitude in the range 500-15000Hz and some increase at the frequencies above 18kHz. Both appr. 2-3 DB. Hope this is an individual calibration, but not a generic one.



Thanks. Yes, my calibration was done at CSL lab and it is certainly not a generic file- It is specific for my individual mic.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I'd love to hear more about this!



Me too!!


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Me too!!


Me three!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It means that soon passive installations could sound as good as the best tuned active systems. Great prospective, Raimonds. Long expected and very desired. 

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----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

My answer to all three : ) about time correction.

It is in prototyping stage right now but we can try to use it to collect experience.

You should have some pretty much good result of AFR correction using Workshop or TDA EQ and with your target - some king of final usable result.

Then, you must make TDA measurement with correction ON and send me IR of that measurement together with FIRs you are using.

I will prepare new FIRs with time correction implemented.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have successfully used the APL1 to fix group delay and even cancellations between L/R. You can create a somewhat decent center without actual time delay for example by messing with the phase response in the vocal region. The main "feature" with FIR is to able to separate magnitude and phase response (group delay is a derivative of the phase response at a given freq). The only issue is that the frequency resolution is pretty low in the lowest octave since the "taps" are evenly distributed throughout the entire frequency range. I haven't tuned anything with the APL in a while now but back when I experimented with this I did it with rePhase.

There is a lot of advanced stuff you can do with FIR processing but as you start to mess with the phase response you might run into issues unless you know exactly what and where to measure. 

I have started to make that video now, I'll upload it to Youtube once I'm done. It will probably be two or even three parts.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> I have successfully used the APL1 to fix group delay and even cancellations between L/R. You can create a somewhat decent center without actual time delay for example by messing with the phase response in the vocal region. The main "feature" with FIR is to able to separate magnitude and phase response (group delay is a derivative of the phase response at a given freq). The only issue is that the frequency resolution is pretty low in the lowest octave since the "taps" are evenly distributed throughout the entire frequency range. I haven't tuned anything with the APL in a while now but back when I experimented with this I did it with rePhase.
> 
> There is a lot of advanced stuff you can do with FIR processing but as you start to mess with the phase response you might run into issues unless you know exactly what and where to measure.
> 
> I have started to make that video now, I'll upload it to Youtube once I'm done. It will probably be two or even three parts.


That's cool. I've actually done quite a bit of that. It works good. Anything less than [email protected] is not enough under 100hz 

But for a midbass , 2048t even at 96k is sufficient (iEEEx32) 
Not sure how well LPCMx24 would do for this ( at least under 300hz) 
I've taken measurements and look at zero phase graph and follow it down hill and any bumps in the smooth downhill I've used phase eq on and have had amazing success combating combfilters and reflections that interfere with left/right uniformity (at one listening position) it really does take flipping polarity on one driver to fix imaging to the next level. Targeting only the offensive area. 

On wrapped or zero phase any peaks up would be sound arriving first and dips would be delayd where phase goes up is where I would focus on making small phase changes due to the fact that trailing errors sound better than leading errors when corrected IME 

Even tho the complexity of mixed phase and it would be difficult to pinpoint exactly where the problem is originating (glass, dash, door,) I've at least noticed the trailing errors are usually accompanied by a dip in the frequency domain. 
So some of it is minimum phase and at least a cut in where timing is advanced will at least behave minimum phase if cuts were used in frequency domain. So it should work as well for the minimum phase parts of mixed phase and have a better chance of the acoustical correction following the desired target correction.
Of course the mixed phase will be affected and the part of the mixed phase that is a reflection and is louder (comb peak) should allow the correction (of mic location) to put the reflection back in time which would be like moving a non linear distortion caused by reflections to be made linear distortion. Still has a comb filter and a reflection, they just reverberate more evenly to the ear at the listening position. These reflections are reverbant, and I think it suggests some things can be done to repair compound reflections. At least in one seat. It's the reverbant nature that makes it so difficult to pinpoint being it would reverberate diffrent dependent on frequency. So one fix may screw up another oactave or suboactave. But small less than 15° cuts in phase (time) seem to work on the small peaks in zero phase responces. And obviously we're flattening out magnitude first so we aren't making some correction on minimum phase which surly would be an error especially if the speaker measures flat phase /close mic 

I can get about 3 small peaks fixed using [email protected] (ieee) 
So your right it does hog up some taps with those narrow Q adjustments. 
But if one were to adress the one main peak around the 2nd comb peak in the midrange (500-1k) that would be plenty and make one hell of a difference. 

The 1st comb would be too modal and interfere with the other side negatively and above 1k your measurements become unpredictable weather it's a comb or not. It would have multiple compound reflections into and you couldn't gauge the accuracy. Granted a inverse mag/frequency should make a mostly flat phase fundamentally, but I don't think any corrections are beneficial or even noticeable up that high. 

Some of this is just my own way of putting it as I am not an acoustical engineer or a expert, but just a dood that screws with this **** a lot. 

But definitely definitely worth exploring and sharing experience


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Could you please illustrate your fine writting with some pictures and graphs. Thanks beforehand. 

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## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Han, if you can do a video walk through of basic usage, from using Workshop to record and generate filters, Config to upload to the APL1 and C1 to make adjustments to eq, that would be excellent.
I'm still also trying to figure out how the presets created in APL Config relate to the preset switch, which doesn't seem to have a starting point for where preset 1 is located to know where to line things up. And Config doesn't number the presets in the software either. Also would be nice to see your measurement technique.

Thanks for stepping up to the plate to make a video for us! It's a very nice tool and the biggest hurdle is just figuring out some of the basic usage stuff.


I started writing up a basic "out of the box" setup guide for myself as I've gone through to setup each of the software components. still a work in progress, but when it is done I'll share that here too. Any corrections can then be vetted by those of you who have more experience with the software(s).


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

As I remember , you could name the presets in Apl Config. Uf you still have problems using this software, you could do it even without presets. Just connect your box and PC with the USB cable. You should get a confirmation that your connection is ok. Switch to the position 1, select two correction files from the Workshop with the same target curve (left and right), upload them and send to the device. Done. Then switch to the position 2, select two other files and do on. Egen ready, disconnect the cable and listen relevant corrections switching positions: 1,2, ...

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## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Could you please illustrate your fine writting with some pictures and graphs. Thanks beforehand.
> 
> Sendt fra min GT-I9505 med Tapatalk


Not my cup of tea , I have 6 kids so it's hard for me to do screen shots (it's time consuming)
But I will for you 

I am actually at work right now , so tonight I'll post a photo of a laptop shot or two. Maybe a video ....makes it easier


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hey Steve, if you open the configure software it will have a display of what preset position the switch is in, as well as the "title" you gave the tune. The title will be in the boxes on the left, and the switch position will be on the bottom right.......you need this to orient your switch correctly with the knob installation.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Good to know Clay. I haven't installed the switch yet, but was using the 3 position bypass switch and wasn't getting anything different between the middle and left positions. I'll connect up the external switch and take a look for what you described.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The switch on the unit, while it has three positions, only toggles the unit from "bypass" to active. The two left positions are both active, and don't change anything. The only change you should notice is the far right position is bypass.......

To actually change any presets you must have the switch hooked up, otherwise there is no way to change....


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

With that switch you will be able to choose between 16 different presets on the go, just by turning the knob while listening music. It might be a good idea to reserve one for mute mod. Selection between active and bypass is easy to do with the help of another switch hooked on the same multi-cable. When connected to the device digitally I use 3-4 presets with a certain reduction in amplitude of the target curve (-6, -12 and. -15dB), as other volume control is not possible in my present setup.

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----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Good ideas.

Clay- Yeah I connected up the preset selector and of course then it made sense. I didn't realize that the bypass switch's 2 left positions were both just "on/active" but it made sense why it never seemed to make a difference when I was toggling between them 

Instead of trimming out the stainless steel enclosure (which doesn't have an actual port on the exterior for the preset switch connector), I decided to use strips of thin felt tape between the enclosure and the lid which provides clearance for the cable and holds it snug.

Is there a sensitivity area range when measuring and looking at the input level bar in Workshop that you guys try to stick to in order to prevent any clipping on the APL1 when turning your source unit volume up?


Another question about measuring and applying target curves...

Do you measure with your calibration file applied AND your target curve applied? It seems like you could alternatively simply measure with the mic calibration only and then afterwords, add in the target curve check box and use the "recalculate" feature to then generate the new fir filters.

Is this how you gents are doing it? Any difference noticed between measuring WITH the target curve applied vs recalculating a basic measurement and applying the target?


Cheers


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Steve, when you say sensitivities, do you mean the level meter in workshop when making measurements? If so, I just get a good response, maybe a third of the way up, and measure from there.

As far as tuning process, I never measure the response with the apl engaged......always in bypass, no correction. I do this because every consecutive tune is a stand alone replacement for the previous, and I want the apl to correct the straight dsp tune, and not assume something is correct already from the measurements and not address previous corrections....hope that makes sense. To put it simply, I always measure with the apl in bypass, always! 

I achieved my best results by defeating all eq, like Raimonds recommends, then I simply entered basic crossovers, symmetrical and 24 db across the board. Entered basic measured distance t/a, then used the ol ears for minor "focus" adjustments to t/a......then centered each pair of drivers by level....then use a level meter to flatten levels by pair to ensure the accuracy of your target curves. After all this basic tuning, I run the workshop software and measure, calculate a correction file, with or without a curve, at this point it doesent matter, and then I activate the apl and listen......any errors you may have made during dsp tuning will likely be amplified by the apl corrections. Listen carefully for errors, not tonality yet, just staging and blend, drivers sticking out and such, make mental note of issues and revisit your dsp tune with the apl once again defeated. Take your notes from the results after apl and pay attention....they may not be as obvious, but they'll be there, same mistakes.....take your time and address them,once yer happy, remeasure, calculate, activate, apply, then listen........ then repeat the process until the corrected results knock yer socks off....it took me about three rounds...lol. Once you have reached a correction file that satisfies you technically, now you can address tonality, but be happy...the measuring is officially over unless ya just want to measure to look at your response! Now you take your finalized correction files and open them, and simply apply a preset target curve over top of the corrections and recalculate as many times as you like....you start with the pre loaded curves Raimonds included in the software, then as soon as ya learn the process for using coneq to create your own files, you'll really get her dialed in to your tastes!


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Are any of you guys using two way front stages? Are you using all pass filters to get good Mideast like Andy talked about a while back, or does/can the correction in the APL eliminate the need for such a thing? Been wondering that fort a while.


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



thehatedguy said:


> Are any of you guys using two way front stages? Are you using all pass filters to get good Mideast like Andy talked about a while back, or does/can the correction in the APL eliminate the need for such a thing? Been wondering that fort a while.


Mine is a three way front. The apl software automatically generates the fir filtering to correct the sound by measuring the power reponse. I assume that part of the corrections are via all pass fir filtering, but this is an assumption, and because the process is calculated and applied for you, I don't really know how many tricks are involved........I just know the results in my system are phenominal.....


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

My Miata is a two way with the IDQ8's high passed at 80hz/12db, no lowpass, off the HU. Plus the factory tweeters with their factory cap. The APL works quite wonderfully on that simple setup.

Late this summer it'll be Mylar CD2 Comps on mini bodies off HU power, and I'll put an 800/4 on the IDQ's. It'll be interesting to see how the APL reacts to the horns.


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## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I think it should be ok since Raimonds has a prosound background and has worked with Danley Sound Labs in the past as well.


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yeah, it'll probably be just fine. It's just gonna be awhile before we find out. I leave on a trip on Monday and will be home for 4 days in late June, and won't be home for any reasonable amount of time until late September.


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## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I might have mine playing by then...hope so.


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## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

APF in IIR definitely have a good place if no fir is at hand 

Nice thing about fir you can target the problem phase area and go back to 0
An APF you can't it shifts to its order no matter what , forcing you to have to cascade them and craft them in a way that is somewhat bad on the signal as a whole. 

Yeah 360 is the same a 0 but it really isn't at lower frequencies, than it takes a whole complicated delay structure on other side to get it back. 

Unless you want to move all the phase at that speaker , an FIr correction would be much better, and wouldn't inherit some of the ringing as well. 

I'm working on the video now. May not post til tomorrow had to work hella late tonight, just got home. And have a store meeting at 7am and have to drive an hour and 20minto work. So....I'll probably wrap up the vid and let it upload all night and hope it doesn't fail (you tube  ) 

But to add to what I was previously talking about, this technique really requires you to know your cars acoustical behavior before even trying to make sence of a phase measurement. 

Only you will know which frequencies still sound too loud even tho you've flattened the magnitude. Yeah power responce tells some and will help discover your cars attitude. 
But when your vocal isn't nailed down center and have to Bal right (in USA) to far to get it more center but still is diffuse , there is a fix.or reversing the polarity on the mid/midbass seems the only way to get a good vocal ... there is a fix also without having to suffer from the lost midbass output or having a strongly weakened left channel just to get vocal clear. 

Anyway....good night y'all I got to try n take a few test measurements so I can finish this


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Steve, when you say sensitivities, do you mean the level meter in workshop when making measurements? If so, I just get a good response, maybe a third of the way up, and measure from there.
> 
> As far as tuning process, I never measure the response with the apl engaged......always in bypass, no correction. I do this because every consecutive tune is a stand alone replacement for the previous, and I want the apl to correct the straight dsp tune, and not assume something is correct already from the measurements and not address previous corrections....hope that makes sense. To put it simply, I always measure with the apl in bypass, always!
> 
> I achieved my best results by defeating all eq, like Raimonds recommends, then I simply entered basic crossovers, symmetrical and 24 db across the board. Entered basic measured distance t/a, then used the ol ears for minor "focus" adjustments to t/a......then centered each pair of drivers by level....then use a level meter to flatten levels by pair to ensure the accuracy of your target curves. After all this basic tuning, I run the workshop software and measure, calculate a correction file, with or without a curve, at this point it doesent matter, and then I activate the apl and listen......any errors you may have made during dsp tuning will likely be amplified by the apl corrections. Listen carefully for errors, not tonality yet, just staging and blend, drivers sticking out and such, make mental note of issues and revisit your dsp tune with the apl once again defeated. Take your notes from the results after apl and pay attention....they may not be as obvious, but they'll be there, same mistakes.....take your time and address them,once yer happy, remeasure, calculate, activate, apply, then listen........ then repeat the process until the corrected results knock yer socks off....it took me about three rounds...lol. Once you have reached a correction file that satisfies you technically, now you can address tonality, but be happy...the measuring is officially over unless ya just want to measure to look at your response! Now you take your finalized correction files and open them, and simply apply a preset target curve over top of the corrections and recalculate as many times as you like....you start with the pre loaded curves Raimonds included in the software, then as soon as ya learn the process for using coneq to create your own files, you'll really get her dialed in to your tastes!



Yup, that's what I meant. This is really helpful Clay, thank you.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Agree with the written above with just few small comments. During the measuring, the level of your signal should be at least 20dB higher than the noise floor. I mean for all frequencies, otherwise it will be difficult for the Workshop to create correct fir-files. Noise curve on the graph is blue, signal curve - green. Finally, when you are fully sutisfied with the sound, remeasure your system and plot two curves: new measurement and rarget. Not for generating new filters, but only for checking purposes - of how apl fits your desired curve. 

With regards to application of the mic calibration file - you are not obliged to use it during the measurements. But not forget it when generating fir-filters.

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What Clay way saying is a must for every car with the expectation for a good sound, never mind you will use apl1 or other DSP. Starting with deadening, vibrarion reduction, new cables, research in XO, leveling of the parallel drives. And only then comes magic of all technology. 

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Yup, that's what I meant. This is really helpful Clay, thank you.


No problem Steve! I want everyone who invests in Raimonds product to get the most out of it they can, I want to keep this genius funded to further his work as I believe his super practical approach to this newer (at least to car audio) technology is truly revolutionary. I'm really glad some advanced tuners such as yourself and John have taken the plunge and are learning how to use it to your advantage, hopefully surpassing your expectations like it did for me.

I don't, however, want anyone who researches this to think it is a bypass for learning all you can about manually tuning a dsp for yourself, this unit is simply a highly intuitive, manual eq replacement, for fine tuning your system, and without the necessary skills to arrive at an already fine sounding system, the apl1 is not an all in one auto tune solution. So don't get the wrong idea when you read about the automatic filter production, the time saving simplicity, and the magic in the end results, as the basics of dsp tuning and the knowlege to get your system where you want it are still required.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Because of exactly the same reason I have started the first apl thead on diymobilaudio in 2014, but nobody was willing to understand me, especially gurus. 

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## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks Claydo for keeping the important stuff on point 
As we attemp to make cherry pie out of dogshit.

Yeah all the corrections in the world are no replacement to a sober install



---------

So I've made 2 videos they keep freezing up after waiting all night to upload 
It just gets stuck on processing (you tube :mad) 
I need a broadband internet. This is so frustrating. 
Sorry guys I'll try again.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks in advance oabeieo! Looking forward to see the video.




Raimonds said:


> You thought right! This option is ready in prototype software.
> But we must turn to such timing correction only after AFR correction is completely done.





oabeieo said:


> Thanks Claydo for keeping the important stuff on point
> As we attemp to make cherry pie out of dogshit.
> 
> Yeah all the corrections in the world are no replacement to a sober install
> 
> 
> 
> ---------
> 
> So I've made 2 videos they keep freezing up after waiting all night to upload
> It just gets stuck on processing (you tube :mad)
> I need a broadband internet. This is so frustrating.
> Sorry guys I'll try again.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hej guys,
Little info about the programme called Coneq C1 Communication tool. I have mentined before that with the help of this soft one can make desired delay of the correction files created by the Workshop. I will try now to explain how. First of all, It is assumed that the program has been corectly installed and connected with the relevant components (C1, etc.). Basically it is a good idea to collect all necessary files on one PC, let call it a measuring PC. When the Workshop is ready with its correction (fir-file), you can delay it quite accurate by using the above mentioned program. Here you are not limited to a certain amount of msec or meters, as you might typically face when using ordinary DSP. Very often it is a limit between 10-15 miliseconds, which is not enough if you have low XO point dividing the subwoofer and midbass, or you have low-pass filter of the fourth order or higher. You will simply need much longer delay, which typically is 40-50 msec or even more. Coneq C1 will help in this very precisely with the accuracy of 0,001 msec in a range from 0 to 4,979 msec. This process is by no means limited and could be repeated as many times is needed. Every time the program will add to the file name a number of miliseconds from the previous session. You could rename it as you wish and make it shorter, which is mucch more practical. 

Number of miliseconds could be derived from the test with a sweap signal by TDA APL. Let say you have done such a test and got a certain number for a delay. What to do?

1. Browse on your PC and apload it to the 
2. Check iff everything is ok and you have selected the right one (target curve, left-right, mic calibration, further corrections by C1, etc.)
3 Move the slide from left to right untill ou will see correct value of msec in a small window on the right from the slider.
4. Correct amlotude value by lowing another slider (if you do not need this step - must skip it over).
5. Press bakeup knob to save your delayed file. Repeat if necessary. Done!

Now you could make it ffor another channel. Enjoy.









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## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It seems so hard to get any good information packed into a 10min video.

I waited all night for it to upload and all day for it to process. I took ****ty measurements that don't really show much as far as a good left right comparison but I finally got one made. Sorry it's not much! 

There was so much more I wanted to speak to as fr as how the measurements, what you see , and how it relates to your listening position. There is a lot to be said on frequency modulation vs. sound propagation and how the near boundaries affect the two interweaved properties of acoustical compression and Rarefaction. Mostly combfilters and acoustical interference. 

So when looking at left vs. right phase measurements you want your mic in the general area your head would be. 
It definitely takes a solid knowledge of how your speakers behave in there locations and the general attitude of the interior. 

Minus the embarrassment of a video , I was playing with rephase and how apl works with phase corrections of this sort. As some of you know I have personally gone a different direction and don't use the apl for unsaid reasons, however it actually does these kinds of corrections quite well with a very low number of taps to achieve a given target. If there was a way to get a rephase file to work on a apl (I think hanatsu had done it ) the apl surly has plenty of power to make a fantastic gloabal phase offset. Pretty nifty actually and the more I run sims the more I can see that this approach really is all one would need to get the big issues resolved in just about any system. 



Anyway without further adduce, here is my ghetto ass 9min throw together that took all of 5 days to get to go live.


https://youtu.be/c0vsqESH6oM


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oabeieo, thanks for your video. Respect for the effort to make it finished despite all technical problems. 

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ya, it works. Has just checked for my left front channel and sub. These are old measurements from 2016, so do not blame hard. It is not my last and best one. Idea was to check only. My experience says it is possible, but takes time to trim all dips, phases, etc. As I remember the apl fixes minimum phase problems automatically. Am I right?









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----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



deeppinkdiver said:


> Im interested in trying this product, APL1. I think I would like 6 channels of control, 2 fro tweeters, 2 for midrange and 2 for midbass. Is this recommended Raimond?





Raimonds said:


> Such a powerful setup will be hard to take under control : )))




This got me thinking..

Does the APL1 unit evenly divide the number of taps between the entire frequency spectrum regardless of the pass band you may be using it in (and thus your target curve)?

Meaning, if I used one APL1 on each pair of speakers actively crossed over in a 3-way plus subwoofer system (1 APL1 for tweeters, 1 for mids, 1 for midbasses, 1 for subs), and I had a specific target curve created for each speaker pair and applied to each individual APL1 for the specific passband and drivers, would it make use of all available taps in the target curve region or are there only "x" number of taps available to be used and they are evenly spread out across the whole FR spectrum?

I imagine that would be a benefit of using multiple APL1 units to provide further correction- particularly in the midbass/sub regions.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

You are right. Taps are evently distributed along the frequency span. I am not sure that it is possible to use more than one limiter per measurement. It is better to ask Raymond if you would keep 4096 taps when limiting some frequency range. 

Sendt fra min GT-I9505 med Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> This got me thinking..
> 
> Does the APL1 unit evenly divide the number of taps between the entire frequency spectrum regardless of the pass band you may be using it in (and thus your target curve)?
> 
> Meaning, if I used one APL1 on each pair of speakers actively crossed over in a 3-way plus subwoofer system (1 APL1 for tweeters, 1 for mids, 1 for midbasses, 1 for subs), and I had a specific target curve created for each speaker pair and applied to each individual APL1 for the specific passband and drivers, would it make use of all available taps in the target curve region or are there only "x" number of taps available to be used and they are evenly spread out across the whole FR spectrum?
> 
> I imagine that would be a benefit of using multiple APL1 units to provide further correction- particularly in the midbass/sub regions.


There’s the APL3 (MTO), but I don’t think it’s designed for this.
I’d be curious to see if it’s adaptable, especially about the software version, to see how it handles the right integration of each channels for a 3 way and not a 5.1.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So I am trying to install the APL Config software on my new computer, but the driver installation keeps failing.

Windows 10 x64



I also tried a different computer with Windows 10 32.

The drivers x86 failed on that computer, also.




Anyone have this working on Windows 10?


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I installed it on my windows 7 x64 laptop.

Are you installing the drivers manually? Does the program itself load up ok?
Try opening the Config program and connecting the laptop to the powered up APL1 with the usb cable. THEN try doing the drivers again. (x64 not x86) Mine was failing too until I did it this way.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> So I am trying to install the APL Config software on my new computer, but the driver installation keeps failing.
> 
> Windows 10 x64
> 
> 
> 
> I also tried a different computer with Windows 10 32.
> 
> The drivers x86 failed on that computer, also.
> 
> 
> 
> 
> Anyone have this working on Windows 10?


You might have to try disabling driver signature for w10.

Sendt fra min T1-A21L med Tapatalk


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Driver signing disabled fixed the issue. Thanks!


Sent from my iPhone using Tapatalk


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> This got me thinking..
> 
> Does the APL1 unit evenly divide the number of taps between the entire frequency spectrum regardless of the pass band you may be using it in (and thus your target curve)?
> 
> Meaning, if I used one APL1 on each pair of speakers actively crossed over in a 3-way plus subwoofer system (1 APL1 for tweeters, 1 for mids, 1 for midbasses, 1 for subs), and I had a specific target curve created for each speaker pair and applied to each individual APL1 for the specific passband and drivers, would it make use of all available taps in the target curve region or are there only "x" number of taps available to be used and they are evenly spread out across the whole FR spectrum?
> 
> I imagine that would be a benefit of using multiple APL1 units to provide further correction- particularly in the midbass/sub regions.



Precisely the question that made me choose 2x4HDs 
I can run multiples and use fir crossovers along with some arbitrary phase corrections all done manually via rephase. 

Multiple apls would have cost too much for what I wanted to do. And I wanted to keep everything at96k

However if someone was to run multiple apls , my goodness that could be quite the dream setup indeed. So much more fir power at 48k, yeah it's more prone to other issues, but realistically at the end of the day if Spotify is what ends up being the source or what not , than its obviously a non issue  


Yeah Raimonds says complicated, he's right. Heck toggling between 3hds and a Dirac is no easy task, but once you get the hang of it and get it mostly dialed in. It would be sweet indeed. Ive seen doods on the diy side say there using as much as 8 2ch opendrc boxes....seems multiple anythings are the way to get in deep and get things the way you want. 

You would be a stud if you did it no doubt


Just read that minidsp is making a 24,000tap per channel box (2ch) ....found this pic also.
As soon as that sucker is out I'll buy one for each pair.....
I would prefer to not use IIR at all and do everything in fir. 
It sounds better, easier to tune, and quickly loadable.

Idk about anyone else, I'm saving my pennies for that to show up.
High tap 100% pure FFT convolution. That will be the hotness. 
But for now I'll fiddle with my multiplex of mini boxes and constantly swap USB drives every time I want to load a file. It's a big ole pita but it's effective 
And believe me, the over 18,000 taps I'm using now IS NOT ENOUGH! 

If you do buy a 2nd apl you will just want more....

free upload imagecertificity.com





forum image hosting


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Driver signing disabled fixed the issue. Thanks!
> 
> 
> Sent from my iPhone using Tapatalk


Dear Friends,

This question is coming time to time. I must clarify it.

Everything is ready for work on W10 and is working on lot of systems already.

But there are some tricky things that must be taken into account.

1) W8 W9 W10 64 bit versions do not allow to install drivers that are not signed by Microsoft.
You must follow such procedure to overcome that:
https://learn.sparkfun.com/tutorial...abling-signed-driver-enforcement-on-windows-8

2) Windows systems is very "quick" to use incorrect drivers (true for 32 and 64 bit systems) In such case they must be updated.
You must find the APL unit in Device Manager. It will be as some COM port in such case.
The first option, by showing directory of drivers, may fail with message that "correct drivers are already used".
You must use second option - "I will chose drivers from the list"

Good luck!
Please feel free to ask for support!


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> ....
> And believe me, the over 18,000 taps I'm using now IS NOT ENOUGH!
> ....


Dear Friend,

You are very far away from understanding of FIR filter`s use.

You are talking about even about 131072 taps "accuracy".
But such FIR filter is 1.3653 seconds long (for 96kHz sr) and your sounds will be smeared through that 1.3653 seconds if you will use such filter.

And so, it is not an accuracy, it is a smearing.

It is very important check how long FIR filter is actually used in particular correction.
Its length must be reasoned with particular correction task.
And FIR filter length must correlate with the Impulse Response length of particular loudspeaker (system) that you are willing to correct.

If you are suggesting to use 131072 FIR you are far into errors.

I am using 4096 tap FIRs (on 48kHz) for 15 years : )))
It is 85.3 ms in time domain.
It is enough for 99% of cases.
Even such big milliseconds are necessary only for a very boomy sub.

The tricky thing is to correctly measure the problem.
If it is done correctly, it will never request more that 2048 taps (42ms) usually.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In pro-sound world people use normally no more than 2048 taps for live concerts due to problems with latency. Too big delay of the amplified sound course difficulties to performers.

Sendt fra min T1-A21L med Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

There is no mandatory connection between latency and taps ... : )
It is for linear phase FIR filter but there is no reason to use it in audio.
For video - welcome!

All FIRs created by APL tools have zero latency.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I think some guys just tend towards overkill.....lol, if some is good more must be better right? Myself, I'm completely happy with what the apl1 is doing in my system, and I'll freely admit I'm not real sure how it works, but I do know that the work Raimonds put into the apl workshop software provides more of the magic than the application of the fir filtering by the apl1. I've poured over the information available on fir filtering, and while I somewhat understand the basics of what it does and even how it does it, it's the building and execution of fir filtering to address the problems that is well beyond me, as well as the "how much, when and where" part of the problem. It seems to me to go well beyond a simple understanding of the complex math involved into an area of knowlege and experience where if you don't have a complete understanding of all that is going on, your likely to do more harm than good. That is where the apl system shines, it's not the means to the end, fir filtering, it's the software's construction and implementation of these filters that's truly revolutionary.......


It's kinda like two doods at a gtg both running the helix pro processor......one car sounds spectacular, one sounds mediocre at best......both have the same tools, one simply knows how to use them to their fullest potential, the other doesent get it.......so having the tools does not win the battle, it only let's you get as far as your knowlege will take you.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Dear Friend,
> 
> You are very far away from understanding of FIR filter`s use.
> 
> You are talking about even about 131072 taps "accuracy".
> But such FIR filter is 1.3653 seconds long (for 96kHz sr) and your sounds will be smeared through that 1.3653 seconds if you will use such filter.
> 
> And so, it is not an accuracy, it is a smearing.
> 
> It is very important check how long FIR filter is actually used in particular correction.
> Its length must be reasoned with particular correction task.
> And FIR filter length must correlate with the Impulse Response length of particular loudspeaker (system) that you are willing to correct.
> 
> If you are suggesting to use 131072 FIR you are far into errors.
> 
> I am using 4096 tap FIRs (on 48kHz) for 15 years : )))
> It is 85.3 ms in time domain.
> It is enough for 99% of cases.
> Even such big milliseconds are necessary only for a very boomy sub.
> 
> The tricky thing is to correctly measure the problem.
> If it is done correctly, it will never request more that 2048 taps (42ms) usually.






I definitely not talking about using a single FFT that long maybe that's the confusion. I'm talking about using multiple devices divided into a 4way, keeping a relatively short FFT. Nice attempt to scold me tho  

If one was to daisy chain boxes , yes your right the impulse (FFT) would be way too long. That chart I posted was an example of ability. Weather it's split into a 4way or not fact still remains , only so much correction can be manipulated with only so much fIr. 

Obviously apl does a phase only correction decently with its ability. 
I was just talking fir in general, and if one was to do all there crossovers, phase corrections, min phase corrections and Lin phase corrections in fir the apl just falls short. Granted it wasn't meant for that, and I wasn't talking about using it that way. 

I was talking about using a pair of apls split up between a 4ch and getting more ability through use of another platforms fir on an apl , (which I am not 100% sure can even be done , some say it can) 

So. I think I was misunderstood.


And on to your system, it's probably not in a car, it probably has amazing flat phase to begin with with a optimal listening position and a optimal acoustical treatments to the room.....if you haven't noticed , we in cars man! My 18,000+ taps divided over 4 dsps going to 4 separate amps have a maximum of 16.2ms latency and a overall 52ms correction, I have control over no more than 2048t at96k and that is just not enough, I can only make a sub filter to 80hz. I try to go lower and simply can't. So no, I whole heartedly disagree that for us , 4096t is simply not enough. 

Run the sims, do a 52ms group delay correction at32hz and make a 50-60hz crossover in fir with 4096t, even at 48k it can't pull it off without serious stop band ripples or a nailed down target what so ever. , midbass and up, sure [email protected] works. Barley. 

For the better part of a year and a half this is all I've been absorbed with. I'm not an expert but I will screw with any device and try every possible way it can be set up and I've just hit brick walls with the corrections I want to be able to do but lack the power to get it done.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> There is no mandatory connection between latency and taps ... : )
> It is for linear phase FIR filter but there is no reason to use it in audio.
> For video - welcome!
> 
> All FIRs created by APL tools have zero latency.


I'll speak for myself , I could care less about latency , 
I'm in a car and dont care to watch video in car.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> I think some guys just tend towards overkill.....lol, if some is good more must be better right? Myself, I'm completely happy with what the apl1 is doing in my system, and I'll freely admit I'm not real sure how it works, but I do know that the work Raimonds put into the apl workshop software provides more of the magic than the application of the fir filtering by the apl1. I've poured over the information available on fir filtering, and while I somewhat understand the basics of what it does and even how it does it, it's the building and execution of fir filtering to address the problems that is well beyond me, as well as the "how much, when and where" part of the problem. It seems to me to go well beyond a simple understanding of the complex math involved into an area of knowlege and experience where if you don't have a complete understanding of all that is going on, your likely to do more harm than good. That is where the apl system shines, it's not the means to the end, fir filtering, it's the software's construction and implementation of these filters that's truly revolutionary.......
> 
> 
> It's kinda like two doods at a gtg both running the helix pro processor......one car sounds spectacular, one sounds mediocre at best......both have the same tools, one simply knows how to use them to their fullest potential, the other doesent get it.......so having the tools does not win the battle, it only let's you get as far as your knowlege will take you.



Yeah I totally agree, incompetence is definitely a issue with tuning with this stuff

you have never heard my car so your analogy doesn't apply to me.  
And I don't own a helix either or an apl so obviously your weren't talking about me. You have a helix right?


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> Yeah I totally agree, incompetence is definitely a issue with tuning with this stuff
> 
> you have never heard my car so your analogy doesn't apply to me.
> And I don't own a helix either or an apl so obviously your weren't talking about me. You have a helix right?


Nope, no helix here, jl twk d8 for me. That analogy was about nobody in particular, just a comparison that simply having access to technology that someone has employed successfully is of no advantage without a matching understanding of the processes involved in the successful implementation of said technology.....in other words, like I've said before, the advantages of the apl system are not as much based strictly on the technology of fir filtering, as much as the conversion of the measurements following the guidelines of Raimonds software into applicable filter construction.....after this filter construction is completed as a correction file, the apl1 unit simply applies them.......


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Nope, no helix here, jl twk d8 for me. That analogy was about nobody in particular, just a comparison that simply having access to technology that someone has employed successfully is of no advantage without a matching understanding of the processes involved in the successful implementation of said technology.....in other words, like I've said before, the advantages of the apl system are not as much based strictly on the technology of fir filtering, as much as the conversion of the measurements following the guidelines of Raimonds software into applicable filter construction.....after this filter construction is completed as a correction file, the apl1 unit simply applies them.......


Oh thank god , I thought this was going to for sure turn into a flame fest. 

I appreciate the prudence. 

Ya know, I just love talking with you guys. And love seeing you all use at least something fir and go through the learning curve. Hell I learn new **** all the time. 

I know a lot of what I say is more related to fir in general, and sharing my experience and fun with correction filters and what not....it's fun ....

In no way do I think bad about apl , it's just a different box for a different purpose. I just enjoy the conversation with all y'alls and like seeing what everyone is doing.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

After tuning with Steve and John today I scanned over the last dozen pages or so of this thread and have some more thoughts...



truckguy said:


> When the apl works its magic does it lower your overall output or does it stay about the same? What kind of requirements does a laptop need to run the workshop software? I bought a very basic Dell laptop a while back just for tuning. When is the group buy happening for the software, apl, and 16 preset switch?!


It does tend to lower your output a bit. However, setting the gains properly is a fluid thing that shouldn't be done just once in the tuning process. Setting the gains should be something that is done multiple times throughout the tuning process.

As we tested today, you will probably have to make more cuts IN the APL1 if you are going digital in than if you are going analog in. If your processor after the APL1 has plenty of boost on the input available, then you are probably fine. It'll be interesting to see what John learns about this over the next couple weeks.



thehatedguy said:


> I need to contact Raimonds...all of my APL software is on a laptop that I will never see again due to divorce issues.
> 
> Sorry Raimonds, been a tough few months...and leaving with nothing.


John, Steve and I talked a bit about this today, what if we lose our flash drive? Have you talked to Raimonds about getting your software up and running again? I've tried cloning my flash drive to transfer to a better drive, and the DRM Raimonds uses is VERY good.

Raimonds, if someone loses a flash drive, or needs to transfer to a different drive, is that option available without purchasing the software again?



Raimonds said:


> My answer to all three : ) about time correction.
> 
> It is in prototyping stage right now but we can try to use it to collect experience.
> 
> You should have some pretty much good result of AFR correction using Workshop or TDA EQ and with your target - some king of final usable result.
> 
> Then, you must make TDA measurement with correction ON and send me IR of that measurement together with FIRs you are using.
> 
> I will prepare new FIRs with time correction implemented.


I will send you some files in the next couple weeks. I have a second APL1 setup in a Peterbilt with a TERRIBLE system. It was great to use as a demo today, but not an optimal system to listen to. It'll be interesting to hear what linear phase changes can do to it. Also, I am in the perfect situation to make a measurement with TDA and the leave the mic in the same exact spot until after you give me new fir files and I can measure again.


------------------------------------------

It was fun to tune with Steve and John today. John's car sounds phenomenal! The purpose of our testing today wasn't to get the perfect tune, instead we wanted to make sure everyone had a good workflow down. 

We took two different kinds of measurements with John's car, one where we measured the whole front listening area, as Raimonds recommends, and another where we only measured the drivers side. John will drive home tomorrow listening to the driver side tune, I'm very curious to hear what he says about it!

I hope John and Steve are both able to run through the tuning process much faster after today.

It was a pleasure to meet you two! I wish we had the time to run through TDA, and more time to show you the toys I work with.

An thanks for dinner Steve!


----------



## dcfis

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sounds like you guys are doing awesome work! We might need a TX Raimonds syndicate.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I live in TX, you just have to catch me when I'm home!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I forgot to mention, when I got back to the Pete to grab my headphones and laptop after dinner I discovered that I had left the APL1 on the whole time. It was still totally cool to the touch, it might have been just slightly warm by the RCA connectors, but still very cool. I'm pretty sure this think generates almost no heat.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



dcfis said:


> Sounds like you guys are doing awesome work! We might need a TX Raimonds syndicate.



It would be nice to be next to valuable customers : )


Headphones.

I highly recommend to everyone who has passion in the sound to have the "reference".
Headphones may serve this because of fact that it is possible to make detailed correction to some kind of absolute reference
when you can put next to each other some pairs of loudspeakers and headphones and get same uncolored reference sound from them.

First time it was demonstrated at AES Convention in October 2006, in San Francisco Moscone Center.












6 different loudspeakers - identical reference sound.












Now it is ready for headphones.
And it is very easy to take them with you and have the reference everywhere.


Cuts and boosts - depends on where is the zero of curve.
You can set that in Workshop.
You can set everything to "cut" mode such way.


The case of FS digital source - it is a "crime" regarding to signal to have no headroom.
It is the result of "volume wars"

We must correct that by introducing a headroom to be able to do signal processing.
First good way is to reduce output level of digital source.
If it is not possible - let`s reduce gain of APL1 unit by applying gain on FIR filter.



Software recovery in case of accident.
Yes of course! Please let me know!

I can not leave my valuable customers in a disaster : )


The driver side measurement.
It may work. 
But you should not forget the part 6 of QSG - "6. Loudspeaker directivity. p. 7"
You can take into account particular listening place effects by use of that procedure.

You should try TDA EQ measurement that is much targeted to the listening (drivers) position.
But it is not completely tested in car environment right now.
Would you like to test it?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am using apl1 in the car around 4-5 hours every day and it is never gets hot. I do not remember if somebody blame this unit for overheating.

Measuring at the listenng (driver) position is a part of a bigger game struggling against overhelming directivity at higher frequencies. It might be actual if tweeters are too bright and produce a lot of near reflections and placed close to ears. Measuments with the Workshop have to be made covering the whole volume of the front part of a cabin including boundaries of appr. 5-10 cm from surfaces. By this you will ensure all the advantages of the apl technology.

Sendt fra min GT-I9505 med Tapatalk


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> I am using apl1 in the car around 4-5 hours every day and it is never gets hot. I do not remember if somebody blame this unit for overheating.
> 
> Measuring at the listenng (driver) position is a part of a bigger game struggling against overhelming directivity at higher frequencies. It might be actual if tweeters are too bright and produce a lot of near reflections and placed close to ears. Measuments with the Workshop have to be made covering the whole volume of the front part of a cabin including boundaries of appr. 5-10 cm from surfaces. By this you will ensure all the advantages of the apl technology.
> 
> Sendt fra min GT-I9505 med Tapatalk



That measurement technique when I first heard it blew my mind. It makes me think does that software somehow triangulate its position in space, creating a 3D response curve for each side, or something cool like that. This thing does still intrigue me, except no fun cash leftover at present 


Sent from my iPhone using Tapatalk Pro


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> I am using apl1 in the car around 4-5 hours every day and it is never gets hot. I do not remember if somebody blame this unit for overheating.


No one claimed it was overheating, we were just wondering if it gets hot at all. 



> Measuring at the listenng (driver) position is a part of a bigger game struggling against overhelming directivity at higher frequencies. It might be actual if tweeters are too bright and produce a lot of near reflections and placed close to ears. Measuments with the Workshop have to be made covering the whole volume of the front part of a cabin including boundaries of appr. 5-10 cm from surfaces. By this you will ensure all the advantages of the apl technology.


We measured both the driver seat and the whole front listening area in John's car. John will be able to tell us more about how tuning with these two different measurements works out for him.



Raimonds said:


> The driver side measurement.
> It may work.
> But you should not forget the part 6 of QSG - "6. Loudspeaker directivity. p. 7"
> You can take into account particular listening place effects by use of that procedure.
> 
> You should try TDA EQ measurement that is much targeted to the listening (drivers) position.
> But it is not completely tested in car environment right now.
> Would you like to test it?


I measured only the driver side in my Miata and it worked well. I'd definitely like to try TDA EQ!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

These pictures present a difference between measurements in the whole cabin volume and at the driver seat - it was rather audible. In a new car with less reflections from different glass surfaces thi effect is quite little. So it depends...
















Sendt fra min T1-A21L med Tapatalk


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> That measurement technique when I first heard it blew my mind. It makes me think does that software somehow triangulate its position in space, creating a 3D response curve for each side, or something cool like that. This thing does still intrigue me, except no fun cash leftover at present
> 
> 
> Sent from my iPhone using Tapatalk Pro


It is not a measuring techniqs which is amasing, but interprtation of the measured results, which you do not see. And this is simply impressive by final results and repeatibility.

Sendt fra min T1-A21L med Tapatalk


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

First, thank you once again John R for taking the time to show us your workflow process for using the software and measuring the vehicle. It was nice to get confirmation that I was doing the right way as I tested it in my temporary setup. It was a pleasure to meet you and to chat about the work you do and our experiences in this hobby over the year. As always, it was a pleasure as well to hang out with John K again too. Good times, good company.

Raimonds- Thank you for confirming that you're there to support us in case of a drive failure or other issue. That is always comforting to know.

I feel like I have a pretty good handle on using the Workshop software now (at least in its most basic functions) and I'm looking forward to experimenting with measuring techniques, building the right target response curves in Coneq peq and evaluating and correcting the basic system setup using the nice visualizations in TDA.

Once I get more time and experience with these, I would certainly be interesting in learning more about TDA EQ and experimenting with it as well.


Cheers


-Steve


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> First, thank you once again John R for taking the time to show us your workflow process for using the software and measuring the vehicle. It was nice to get confirmation that I was doing the right way as I tested it in my temporary setup. It was a pleasure to meet you and to chat about the work you do and our experiences in this hobby over the year. As always, it was a pleasure as well to hang out with John K again too. Good times, good company.
> 
> Raimonds- Thank you for confirming that you're there to support us in case of a drive failure or other issue. That is always comforting to know.
> 
> I feel like I have a pretty good handle on using the Workshop software now (at least in its most basic functions) and I'm looking forward to experimenting with measuring techniques, building the right target response curves in Coneq peq and evaluating and correcting the basic system setup using the nice visualizations in TDA.
> 
> Once I get more time and experience with these, I would certainly be interesting in learning more about TDA EQ and experimenting with it as well.
> 
> 
> Cheers
> 
> 
> -Steve


Thanks, it was a pleasure to meet you! And thanks for dinner! 

Going over the process with you and John helped me too, mostly because it made me think about what exactly I was doing, and why. It also helps to keep this stuff fresh in my mind. I'll play with the Pete over the week, and the APL will most likely stay in it for the next 11 weeks.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks John R for spending your time with Steve and me.

I definitely have a better understanding for the process and also a series of ideas I want to test out soon.


After driving home and doing some A/B switching on the APL1 between active and bypass, I definitely can hear the effect on the soundstage dimensions when using it. My stage gets wider and more 3 Dimensional. I still prefer the tonality on my Helix tune by itself, but I think once I have found a target curve for the APL that I like it will be better.

Anyway, lot's of stuff to try out now. I'll keep reporting back.

Thanks again!


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I am pretty sure that you can get much closer to your desired target curve with the all1 than with Helix. And with more clean sound. 

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## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I'm a bit of a stalker in this thread as I try and learn more about the APL. For me there are two distinct parts to tuning, with measurements and finally by ear. So we've set the cross overs, measured and set the delays and eq'd each driver to the built in house curve. But this is a base and no matter how good the base, it's never accurate to the ref sound, it can't be because each install and the acoustics of each car will be different. Close yes, very good sure, but it will still need work and this is where tuning by ear starts.

So lets say the APL has got me to this point, now I want to tune things manually and I'm looking for 1/3 oct eq per driver with a resolution of say +/- 0.2 db and TA per driver in steps of say 0.01. The reason I need this is because, that is how my brain is used to tuning. Hear an issue, is it timing or response, if timing which driver, if response what frequency which side or overall etc etc. 

Long story short, I am just wondering what sort of eq and TA would I have on each driver once the unit has done its magic.


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> I'm a bit of a stalker in this thread as I try and learn more about the APL. For me there are two distinct parts to tuning, with measurements and finally by ear. So we've set the cross overs, measured and set the delays and eq'd each driver to the built in house curve. But this is a base and no matter how good the base, it's never accurate to the ref sound, it can't be because each install and the acoustics of each car will be different. Close yes, very good sure, but it will still need work and this is where tuning by ear starts.
> 
> So lets say the APL has got me to this point, now I want to tune things manually and I'm looking for 1/3 oct eq per driver with a resolution of say +/- 0.2 db and TA per driver in steps of say 0.01. The reason I need this is because, that is how my brain is used to tuning. Hear an issue, is it timing or response, if timing which driver, if response what frequency which side or overall etc etc.
> 
> Long story short, I am just wondering what sort of eq and TA would I have on each driver once the unit has done its magic.


You can achive accuracy in TA down to 0.001 msec. Max value is not limited as far as I am concerned. But this is per channel. If you buy apl3m unit, you will have 6 channels. XO points could be made by parametric equaliser with almost anlimited settings for F and Q. You could add as many corrections afterwords as you wish. Yes, fine tuning by far is a final art here. But again, do not mix APFR and FR measured just in one point. 

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

One have to remember, that apl1 is not a dedicated time machine, so it is little bit Tricky to make TA with it. You can not do it on the go and need a PC with a soft called ConneqC1. My suggestion is to use another DSP for this purpose, test with TDA APL, measure the precise value and correct your previous TA. 

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> I'm a bit of a stalker in this thread as I try and learn more about the APL. For me there are two distinct parts to tuning, with measurements and finally by ear. So we've set the cross overs, measured and set the delays and eq'd each driver to the built in house curve. But this is a base and no matter how good the base, it's never accurate to the ref sound, it can't be because each install and the acoustics of each car will be different. Close yes, very good sure, but it will still need work and this is where tuning by ear starts.
> 
> So lets say the APL has got me to this point, now I want to tune things manually and I'm looking for 1/3 oct eq per driver with a resolution of say +/- 0.2 db and TA per driver in steps of say 0.01. The reason I need this is because, that is how my brain is used to tuning. Hear an issue, is it timing or response, if timing which driver, if response what frequency which side or overall etc etc.
> 
> Long story short, I am just wondering what sort of eq and TA would I have on each driver once the unit has done its magic.


You still have all the tuning accuracy of your dsp in your signal chain after the apl1 unit. You're free to tune to your hearts content after the apl does its stuff, but personally I don't recommend it......the apl suite of measurement software and apl1 unit do a far better job at matching l/r eq than I ever accomplished using measurements or by ear, it does a remarkable job. You see the apl is not a manual eq, it matches the power response of the left and right sides automatically, the only manual eq adjustments left for you is the tonality curve to your preference. If you are not happy with the automatic l/r eq you could always make independent l/r target curves to suit your ears, but I'm telling you the power response measurements matches l/r past my point of needing any tweaking. However, you can fine tune everything via your dsp after the fact if ya want........

As for the tweaking of the timing after the apl auto eq, if there is errors in level or timing they stick out like a sore thumb after the apl tuning......I simply defeat the apl processing and revisit the errors in my dsp tune, then remeasure with the apl workshop and reapply, until I'm not picking up any errors..........

The apl is a different system than a traditional tuner is used to dealing with, so it does make you rethink some traditional processes......some get kicked to the curb, some are approached in a different method. It is really a unique unit, that is difficult to comprehend without direct experience with the results........


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> ... +/- 0.2 db and TA per driver in steps of say 0.01.


You're kidding right?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> You're kidding right?


We have to be realistic and remember threshold values for a human ear at different frequencies. While driving, your ears are moving constantly much more than a distance calculated by using a time of 0.01 msec and sound velocity in the air under usual conditions ?

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## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> You're kidding right?


No I'm not. It depends on how trained the ears are, NOT golden ears. KP mentioned in one of his posts that he does his rough tune at +/- 0.3 db and then fine tunes at +/- 0.1 db. It's like if you run 5 miles a day and I don't, chances are you can run faster and further than I can. Same thing here.

My bit10 is +/- 0.3db and I just like my next processor to be slightly finer in eq resolution.


----------



## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> We have to be realistic and remember threshold values for a human ear at different frequencies. While driving, your ears are moving constantly much more than a distance calculated by using a time of 0.01 msec and sound velocity in the air under usual conditions ?
> 
> Sendt fra min GT-I9505 med Tapatalk


Tuning on the fly is a terrible addiction (says someone who did it incessantly for a couple of years). If the car is quiet to begin with, then a good engine on tune is very listenable on the road. Otoh if like me, you have 85db of floor noise at 50mph then yeah, we need two tunes. I finally just gave up doing it on the fly and would just listen while driving and think of what all needed to be corrected and do it when I got the chance. Rinse and repeat, it went quicker.

By virtue of its design, the ear is incredible at picking and evaluating differences in (time / amplitude / phase), but horrible at evaluating absolutes. So even the best trained ears eg trained musicians will not be able to reliably tell if a sound is 80 db or 81 db, but will hear a difference of 0.1 db at 500hz or a pitch difference of 5 cents or a timing gap of small fractions of m/s. Like you mentioned this sensitivity varies across the frequency range.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



sqnut said:


> No I'm not. It depends on how trained the ears are, NOT golden ears. KP mentioned in one of his posts that he does his rough tune at +/- 0.3 db and then fine tunes at +/- 0.1 db. It's like if you run 5 miles a day and I don't, chances are you can run faster and further than I can. Same thing here.
> 
> My bit10 is +/- 0.3db and I just like my next processor to be slightly finer in eq resolution.


You're right, this makes sense. I'm sure I'm less trained than you but I did realized I could hear this small differences while tuning TA for example, but it's on few octaves (Harder to decide if it gets better or not though).
I jumped on the +/-0.2db but shouldn't have, especially cutting your quote.
And your response to Alex makes a lot of sense too.

It's just that since I went APl and now Dirac, it changed a lot my method.
I don't know, feels like I always get results that are more coherent and stable now. Little tweaks here and there are no longer needed, for me.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Thanks! Audible, not to me lol, the dog may not like it if he goes for a ride.......my last adjustment is a broad cut centered at 22k, what you see is simply the curve rising back to zero......
> 
> Oliverlim, I don't know how to attach the text file here......sorry.


Can I get s copy of your target curve as a text file. Wonna try in my car. Curios about it. It might be little bit colder in mid range compared to MP1, right? 

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## sqnut

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> You're right, this makes sense... but I did realized I could hear this small differences while tuning TA for example, but it's on few octaves (Harder to decide if it gets better or not though).


Very Small TA changes are most audible in the ~100hz to 1.5khz range and slightly less so from 1.5-~3khz, in this range we are picking differences based on both timing and spl difference. Above 3khz you would need a much bigger change to notice a change, because now our ears are primarily hearing differences based on amplitude differences.



Elgrosso said:


> I jumped on the +/-0.2db but shouldn't have, especially cutting your quote.
> And your response to Alex makes a lot of sense too.


No issues, I'm glad the explanation helped.


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## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello Friends,

Regarding "tonality" and target curves as subterFUSE pointed.

The aim of 15 year work was to remove "colorations" of loudspeaker`s sound.
But the "tonality" is not a coloration, it is about your target
It is possible to keep your "tonality" - the large scale fr. response behavior of your system -
but remove (correct) narrow bandwidth problems that are creating coloration.

You should catch your "tonality" curve by heavy smoothing of Workshop`s measurement - by use of "1 octave" at least and edit it.
Then you are ready to use it as your target curve.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Narrow bandwith dips are also not to be underestimated, as it is there you are missing some musical information simply by masking it by neighboring frequencies, which are more loud. Of course, peaks are more audible and contribute more evident to a coloration. One of the biggest benefits of the, apl-technology from the musical point of view, is that a corrected FR allows to hear more details, instruments and environment effects, despite we are talking of the air around acoustic instruments, breathing of a singer, touching the strings or something else. 

And of course, there is a good question, if one have to keep the preliminary tonality of loudspeakers made by the manufacturer, or to create his own, which might reproduce music more close to the composer's intention and vision. What is a great sound? Is it a sound, that does not focusing on the loudspeaker output, but rather on feeling connected to the music content. You forget about the placement of the loudspeakers, tests and measurements and just digging into the world of music. That is what the whole apl-story about. 

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## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

, alextaastrup that pretty much exactly how I feel as well.
You definitely have a strong understanding of this, I hope to learn stuff from you as this continues. 

To further that, I would add the narrow band stuff (at least to me) 
Really needs to be analyzed carefully and executed with prudence.

I've worked on many parts of narrow and wide band errors between left and right , a lot of which was a wasted effort (but a great learning experience) 

I've had phenomenal luck just focusing on narrow band in the diffuse region (500-1k) 
Modal areas I've had some luck but usually accompanied by a ill effect. And under 250hz seems everything is minimum phase so just plain eq works well. (Minus a global alignment to everything else) 

Above 1k , I seem to not be able to trust the gated vs non gated , and really can't pinpoint much, I've had some luck with as high as 1.6k but much after that it becomes sketchy at best as far as measurements go.

But yeah , I so agree with what your saying, I have done as little as fix one narrow band high Q anomaly and had ambiance come alive and an annoying echo almost from a reflection disappear. Not to mention the center being firmly grounded. All by one simple fix at 630hz.


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## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hello Friends,
> 
> 
> You should catch your "tonality" curve by heavy smoothing of Workshop`s measurement - by use of "1 octave" at least and edit it.
> Then you are ready to use it as your target curve.


Could you explain this a little bit more? I been trying to find a way to better get a curve. The con-EQ way is easy to approximate a house curve, but difficult to get the exact type of curve you are looking for.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If I understood this correctly, you might wish to preserve your existing tonality. If so, you measure APFR with the Workshop, smooth it as much as possible (1 octave) to avoid narrow bandwith peaks and dips. Then, by saving the result you will create a curve, which is close to your actual sound, but very smooth. It coud be used as a target/house curve. Applying this curve as a target, you will struggle automatically against measured peaks and dips. New fir-filter will attain the same tonality, if this was your goal. Apload/send it to the apl1 box a d here we are. Enjoy listening.

I will prefer instead for to correct the measured signal to strait line and use as the first step one of the target curves, provided by the vendor. Usually I start with mp1 curve, as it is close to my preferencies. Then you are free to improve the sound further. Many forum members using this unlimited feature. Claydo is one of them. Apl software package comprises a well designed parametric equaliser for this purpose. Now rely only on your own taste ....

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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Indeed Alex, building curves within c1 is super fun, and not very complicated, so it can become addictive. Throw in the ability to save and easily access 16 of them for listening via the switch, and you can create and load up a bunch for comparison. The only hurdle that took me a minute to figure out, is that in order to modify a curve that you previously built, I found it necessary to save a version of each curve in two formats, one version that apl recognizes, as well as one that c1 recognizes so you can start your tweaking from the same place you left it......once you figure this part out you can tweak and modify your own created curves to your hearts content, getting everything just so........


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I love it too and appreciate the possibility to change EQ presets with easy touch. Little of-topic: due t exactly this reason I
I have selected Hidizs A100 because of eternal button on the left side for switching between presets.

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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I bet I asked this already.. Apologize if so. 

Do you have to remeasure with mic for each curve change or does it go by already established measurement data?


Sent from my iPhone using Tapatalk Pro


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> I bet I asked this already.. Apologize if so.
> 
> Do you have to remeasure with mic for each curve change or does it go by already established measurement data?
> 
> 
> Sent from my iPhone using Tapatalk Pro


Nope.....you can overlay your curves over top of your corrections as many times as you want......all from one set of measurements. Another favorite feature of mine, change tonality all you want, and your corrections always stay in place........that's pretty sweet!


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Nope.....you can overlay your curves over top of your corrections as many times as you want......all from one set of measurements. Another favorite feature of mine, change tonality all you want, and your corrections always stay in place........that's pretty sweet!


Ok hang on Master Blaster.  Whatchu talkin' about Willis?

"Overlay your curves".. This means basically putting in your new curve and telling it, go? In which case it wipes out old and applies the new after the algorithm does it's thing?

"change tonality all you want, and your corrections always stay in place"
.. Huh? You mean your previous corrections are banked somewhere or some kind of base corrections? 

Dude I shoulda spent some time with you teaching me the APL tool instead of tuning cars, jawing, and sneaking cocktail shrimpies last weekend. LOL!!


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## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The corrections are stored in one file......the target curves in another, you simply remove one target curve, and replace it with another, tell the software to "recalculate" and blammo, yer done. It's so easy it's rediculous.....you never have to touch the mic or your correction files when changing tonality......it's a giant feature for me, to say the least, being able to change tonality without affecting the corrections.....lmao, try that on a regular eq......


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Random question about the VST plugin,

Is it possible to use on a system level for all sound? Windows OS sound or is it app specific, such as fubar?

Im considering running it from my CarPC, but unsure if the APL only works in specific programs. Because wouldn't the sound get wonky (applying apl and bypassing apl) going between various sources other than that particular app? Or would I need an actual APL1 for this?

If my question is confusing my apologies I can clarify, thanks!


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> The corrections are stored in one file......the target curves in another, you simply remove one target curve, and replace it with another, tell the software to "recalculate" and blammo, yer done. It's so easy it's rediculous.....you never have to touch the mic or your correction files when changing tonality......it's a giant feature for me, to say the least, being able to change tonality without affecting the corrections.....lmao, try that on a regular eq......


Yep! If you don't change anything downstream of the APL, then your initial measurements are still good and you just need to recalculate with different target curves to experiment. No need to remeasure. 

Also, when you start playing with a bunch of different curves it becomes important to name them in Workshop! It can get confusing real fast!


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Random question about the VST plugin,
> 
> Is it possible to use on a system level for all sound? Windows OS sound or is it app specific, such as fubar?
> 
> Im considering running it from my CarPC, but unsure if the APL only works in specific programs. Because wouldn't the sound get wonky (applying apl and bypassing apl) going between various sources other than that particular app? Or would I need an actual APL1 for this?
> 
> If my question is confusing my apologies I can clarify, thanks!


I understand your question, but don't have an answer, sorry. I don't do audio on my Windows computers.


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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> The corrections are stored in one file......the target curves in another, you simply remove one target curve, and replace it with another, tell the software to "recalculate" and blammo, yer done. It's so easy it's rediculous.....you never have to touch the mic or your correction files when changing tonality......it's a giant feature for me, to say the least, being able to change tonality without affecting the corrections.....lmao, try that on a regular eq......


Blammo is a good thing.  Thanks for the clarification.



LumbermanSVO said:


> Yep! If you don't change anything downstream of the APL, then your initial measurements are still good and you just need to recalculate with different target curves to experiment. No need to remeasure.
> 
> Also, when you start playing with a bunch of different curves it becomes important to name them in Workshop! It can get confusing real fast!


I can imagine. Makes me think, post measurement with some other tool such as REW or other to compare the software's accuracy. I imagine it's pretty darn good. Don't quite understand how it does it's thing with measuring a plane in front of you but ya know what, if it gets the job done and it's on the money with coherence and phase as well as response, badda boom badda bing.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Babs said:


> Blammo is a good thing.  Thanks for the clarification.
> 
> 
> 
> I can imagine. Makes me think, post measurement with some other tool such as REW or other to compare the software's accuracy. I imagine it's pretty darn good. Don't quite understand how it does it's thing with measuring a plane in front of you but ya know what, if it gets the job done and it's on the money with coherence and phase as well as response, badda boom badda bing.


With REW you measure the amplitude-frequency responce. With APL(Workshop) - acoustic power frequency responce. Power is not measured at one point. Remembering this, you can not make accuracy check of two principally different things. REW measurement is a part of Workshop measurement. As I remember, Hanatsu has made comparison of flat curves by both programs and found out, that apl curve has a little slope down at higher frequencies, which indeed more comfortable for listening. But, who listen to a flat house curve? 



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## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> With REW you measure the amplitude-frequency responce. With APL(Workshop) - acoustic power frequency responce. Power is not measured at one point. Remembering this, you can not make accuracy check of two principally different things. REW measurement is a part of Workshop measurement. As I remember, Hanatsu has made comparison of flat curves by both programs and found out, that apl curve has a little slope down at higher frequencies, which indeed more comfortable for listening. But, who listen to a flat house curve?
> 
> Sendt fra min T1-A21L med Tapatalk


Understood.. Plus you guys have expressed how consistent APL mic measurements are from one measurement to another, so I'd guess one good high-sample measurement, then let the fun happen by playing with house curves. 

Much of good tuning is speed.. The more progress in short period of time, the more you can do in a tuning session. By APL1 automating that tonality work certainly cuts that time to possibly a tenth of what it would normally be.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Random question about the VST plugin,
> 
> Is it possible to use on a system level for all sound? Windows OS sound or is it app specific, such as fubar?
> 
> Im considering running it from my CarPC, but unsure if the APL only works in specific programs. Because wouldn't the sound get wonky (applying apl and bypassing apl) going between various sources other than that particular app? Or would I need an actual APL1 for this?
> 
> If my question is confusing my apologies I can clarify, thanks!


It is actually very good question. It is possible to rearrange interconnections at the system level of Windows OS. You need for this Minihost Modular or something similar. Be honest, never tried this program by myself as I very satisfied how apl vst plugin works together with Foobar2000.

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Random question about the VST plugin,
> 
> Is it possible to use on a system level for all sound? Windows OS sound or is it app specific, such as fubar?
> 
> Im considering running it from my CarPC, but unsure if the APL only works in specific programs. Because wouldn't the sound get wonky (applying apl and bypassing apl) going between various sources other than that particular app? Or would I need an actual APL1 for this?
> 
> If my question is confusing my apologies I can clarify, thanks!


https://www.image-line.com/support/FLHelp/html/plugins/Minihost Modular.htm

Check this fine video tutorial of how to setup and use the Minihost Modular. By the way, it is free. You do not need an apl1 box for it. Just vst plugin.

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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

When John, Steve and I met up we tuned my 2016 Peterbilt 579, mostly to just walk through the process step-by-step. It was a fairly similar setup to my Miata, iPhone into the APL1, then into the Aux input on the factory radio. The factory stereo is simple, tweeters in the A-pillars, unknown mids in the doors, and a single 10" sub under the bed. The power and crossover points are unknown.

Yesterday I drove the truck for the first time since then, about 6 hours of driving. I was quite pleased with the outcome! It was MUCH more lively, everything sounds much more realistic. The cab is crazy wide and it was hard to pinpoint the far right side of the stage, but the left side is WAY out past the pillar now.

It's not even close to a competition vehicle, but it sounds MUCH better than it did before.


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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It seems you need to optimise TA. You have to delay left fir-filter if your HU is not capable doing it. Your scene will be corrected with a centre just behind the back mirror, if everything is done right. And you will be more happy. 

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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yeah, I might adjust delay this week. I don;t have a rearview mirror, it would just show me the bunk 

Once my Bronco has a functional dash again, this APL1 will go into it.


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## Alextaastrup

*Re: Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Some pictures from the apl run. Before and after - with intention to keep the same tonality, as the speakers had originally. It is mostly for them, who could not find a reasonable target curve in the apl software package.
















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## Alextaastrup

*Re: Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Some time ago Raimonds made a proposal for them, who will preserve the speakers own tonality. I tried by myself and could just confirm - it works. Look at my previous post with 2 graphs. 

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## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Some time ago Raimonds made a proposal for them, who will preserve the speakers own tonality. I tried by myself and could just confirm - it works. Look at these two graphs in the previous post. Before and after - for both channels: right and left. To make a target curve it is recommended to smooth it by 1 octave. Do not forget - there should be only one target curve for both channels: *.prs file.
> 
> How it sounds? Very close to the preliminary sound, but more balanced. Smoothing will reduce influence of peaks, so all in all it is little bit more pleasant for ears. But do not expect a huge difference.
> 
> Sendt fra min GT-I9505 med Tapatalk




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## josby

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Hanatsu said:


> *3. APL uses multiple measurement points to find out the true sound power response (direct sound + reflections) of the listening space. This is feature different from using pink noise and an RTA.*


Do you think this is a better way to measure a system than pink noise + RTA? 

And if so, do you think there's any value in users of other DSP's (who do not have an APL1) using APL Workshop for measurement? That is, is APL Workshop a better tool for seeing what problems a system has, even if one's DSP may be limited in its ability to correct them compared to the APL1?


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Would love a video of the target load up and measurement in action.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



josby said:


> Do you think this is a better way to measure a system than pink noise + RTA?
> 
> And if so, do you think there's any value in users of other DSP's (who do not have an APL1) using APL Workshop for measurement? That is, is APL Workshop a better tool for seeing what problems a system has, even if one's DSP may be limited in its ability to correct them compared to the APL1?



It is definitely a good way to see holes in your response, or to learn from a different point of view.
You can simulate it in REW, or easier in Fuzzmeasure with a bunch of mini sweeps all around.
(though I don't know if workshop uses a very specific averaging method to display the final response)

So better I don't know, but I’m now at the point that I use laaaarge area to tune.
Even if you can’t fix them all without the device, you can still optimize with other XO or EQ decision.

It's possible you won't like the end result (without the time correction from the device) but at least you'll learn new things on your system.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Just purchased the Workshop + VST plugin

Wooohooo!

Though I don't have a measurement mic at the moment.


----------



## 156546

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

OK. I've just read this entire thread...again.

This thing seems pretty cool. From what I can gather here, this system (software and hardware) measures a spatial average over the entire car's cabin, averages those curves, generates a minimum phase response for the average (since there is no phase in an average of magnitude measurements) and applies a 4096 tap FIR filter to the average with target curves designed for a suitable power response (and some other target curves that offer various and obvious differences, like more bass, less midrange and so on and so forth. 

Am I missing something? 

It also appears that the benefits of this process, when compared to the 1/3rd octave analysis with a single mic are well known--better correlation with what we hear at high frequencies and the ability to discern speaker response anomalies and anomalies caused by room reflections.

It also appears that there is some additional software on the way which will allow the addition of applying some phase correction independent of the minimum phase of the correction filter that's generated by the auto EQ.

Is that what this thing does?


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yup....that's it! A nice bonus is the included software to generate custom target curves which can be applied directly over the correction curves as well. It all works together quite nicely.


----------



## Babs

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

Yeah makes me think also Raimonds has some world-class algorithms going on, comparing the two sides for phase coherence possibly at each sample point in space maybe, as time and phase between sides will be different at each point in space where the mic is at that time. Since response between like drivers and between sides in crossover regions playing together will vary because of time domain. Then I get a headache. LOL! Pretty brilliant stuff. Wish I had one to play with. Not going to happen though I'm afraid. Position got eliminated so I'm free-agent for a while. No extraneous spending. 


Sent from my iPhone using Tapatalk Pro


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I wouldn't be surprised if there's some kind of phases average too since it's all sweeps, it would be a miss to not use them.
I know it's 400+ measurements, so impossible to correlate phase to a specific position, but maybe there's a special way to sort/filter them, to extract useful phase information for a better filter?
Not per mic positions obviously but overall, like a way to detect worst responses and not correct or less correct around these. 
Thus the need for a good pre-tune around crossover, without holes in the spfr.

But yes, "better correlation" with what I heard was definitly the big improvment.
Helped a lot.


----------



## 156546

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How about we dispense with the "I'll bet" and the "probably" and the the "I wouldn't be surprised" talk about what things are?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So you only want Raymonds' answer?


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



GotFrogs said:


> How about we dispense with the "I'll bet" and the "probably" and the the "I wouldn't be surprised" talk about what things are?


I can speak to specifics about the results of the unit and softwares effect on the sound in my system, but I'm afraid the details of how it arrives at this point is unknown to me. To me it seems Raimond's approach is simply an improvement on the typical tools for measuring the response of our systems, or maybe his algorithms are just an improvement on the reading of said response, vs my own, to arrive at a levels of cohesion between drivers that I had never achieved through more conventional processes. The strongest attribute for me is the efficiency his method achieves in the simplification of the process, and the consistency of the results, neither an easily attainable goal using any other method I'm aware of......although not saying it doesent exist......


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

To get the ins and outs of Raimonds proprietary (and patented, I believe) processes, I'm afraid mr. W, you will likely have to speak to the man directly........


----------



## 156546

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> So you only want Raymonds' answer?


Not necessarily. I just think that the facts are much more useful than conjecture. 

I also gather, from the response here, that the results are often pleasing. That's good. Repeatability is one measure of the quality of an automated process.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



GotFrogs said:


> Not necessarily. I just think that the facts are much more useful than conjecture.
> 
> I also gather, from the response here, that the results are often pleasing. That's good. Repeatability is one measure of the quality of an automated process.


Unfortunately, Raimonds doesn't give out too much information about how it processes the data. Maybe he would in a more private conversation?

I've used it in a couple cars now and it works quite wonderfully. The learning curve was steep, as I'm sure you saw, but now that I know what I'm doing, tuning is very fast and consistent.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> The learning curve was steep, as I'm sure you saw, but now that I know what I'm doing, tuning is very fast and consistent.


i have mine coming in about a week. after looking at the software and even trying to follow the guide word for word, im probably still going to need help


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi,
It is possible to offer support for any stage of work with APL tools for any place in the world. Thanks to TeamViewer and Skype!
Please use such chance!
BR,
Raimonds


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi,
> It is possible to offer support for any stage of work with APL tools for any place in the world. Thanks to TeamViewer and Skype!
> Please use such chance!
> BR,
> Raimonds


My tuning laptop is probably to slow for team viewer but maybe we can do a demo on my desktop?

Sent from my VS988 using Tapatalk


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> i have mine coming in about a week. after looking at the software and even trying to follow the guide word for word, im probably still going to need help



Give me a call before you install or run setup on anything. Including where you drop the files to that Raimonds sends you.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Give me a call before you install or run setup on anything. Including where you drop the files to that Raimonds sends you.


Already installed to a usb stick

Sent from my VS988 using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hello Friends,



Some time ago I mentioned that it is very tricky to use FIRs to create a multi way system – to create a crossover.
Here is a solution – the software called C5.
The software is offering all the necessary management to operate the multi way system.
It allows to exploit a power of FIR to create an ideal crossover. Why ideal?
Because it incorporates correction for each particular band/way.



Take a look on some screen shoots and results.
The system „under test” was large PA with some bands already with acoustic filters (band pass). It is almost impossible to tune ordinary dsp for work with such system.
But the use of correction on each particular band allows to use very delicate crossover (LR24), get very low crossover’s group delay, as result, and possibility to correct it by sacrificing only 12 ms of latency.
APL has idea to create a 10 channel unit for DSP use – 4 channels with 8192 taps,6 channels with 4096 taps. For use as 5 way DSP or 4 way DSP with master EQ on its input.

Please vote, is such unit necessary or not?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

This is EXACTLY what I need for my Bronco. I vote an enthusiastic YES!

Will this have optical and digital coax inputs as well as analog? How many analog?


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Uh......yes, please!


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Wow, that’s the graal here, would be really great!
I was about to ask about flexibility in taps allocation but it’s so many taps it’s probably not needed. 
Can you share the software process a bit?


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So this would be a DSP/APL "all in one" solution?!

Ironically I was thinking to myself the other day when Gotfrogs posted...

How cool it would be to see an Audiofrog dsp / APL collaboration, that would be awesome! 

Now this.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Still trying to wrap my head around these kind of graphs.


----------



## fullergoku

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

yes its needed!! would the VST plugin be available before the hardware example?


----------



## neoysj

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yes

100% necesary
it will be good also if there is the possibility of custom crossover


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Being able to add a physical volume knob would be wonderful. Then I could go digital from my phone, into the processor, then amps. No head unit, no extra doodads, and I wouldn't have to try and track down a couple of old Audio Control MVC's.


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

In my mind needing a DSP with the APL1 is largely a waste since the DSP would primarily be used as a crossover. If the APL1 was expanded to handle a 3-way stereo plus sub setup with crossovers included, that would remove a piece of equipment and complexity from a stereo system. To me this is a HUGE plus. It would also be a much easier sale since the APL1 "Complete" would be competing directly against a DSP purchase instead of an add-on to a system. 

With an APL1 and a DSP, that is two purchases, learning of two systems, and for those that only buy one item at a time, the DSP would be the purchase and then the APL1, might or might not get purchased later. 

If a DSP was no longer needed, the APL1 could then become the single purchase, only one system would need to be learned, and the system would be less complex and take up less space in a car.

So I think the APL1 "Complete" could be a very successful product.

As an aside, I've been thinking of how I could use an APL1 with my home theater business as a manufacturer of subwoofers and in the future speakers. An APL1 with 3-way capability would be VERY, VERY intriguing to me and effective for my customers.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I emailed Raimonds, so I'm sure he'll respond but he's a busy man and said he had limited internet access while he was away (on business?)...

Anyone know If I can use the VST plugin on two computers at same time? I would like to try it on my home PC first before moving out to my CarPC to ensure I understand how to use it first. I've never tried VST's before, new world for me and Id hate to lock my VST to one specific PC.

Thanks for any advice


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Being able to add a physical volume knob would be wonderful. Then I could go digital from my phone, into the processor, then amps. No head unit, no extra doodads, and I wouldn't have to try and track down a couple of old Audio Control MVC's.


Oh yes very good point!


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds is the man! He got back to me already. 

What customer service.

He say's the VST plugin can be used in trial mode on any PC, and when ready, to send some info and he'll shoot me the license key for full access on one designated PC.

If this has already been asked and answered, my apologies. Hoping would help anyone else with similar question.



Workshop installed on a usb flash drive can be used on any PC with full functionality.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I ran into a problem with Workshop today. I have the same issue no matter what laptop I use.

After taking a measurement, if I go to add any target/correction curves, when I click "Calculate" I get this error:










If I go to the left window and right click on the measurement and try to send it to a channel, I get this error:










I can look at the graph, so there IS something there, I just can't do anything with the measurements.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

It worked with this folder before?
I’m probably wrong as I don't remember exactly, but I think there was a need to use a root folder.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nothing has changed since I last used it in Virginia a couple months ago. Even without setting up the root folder properly, I should be able to calculate new filters without an issue.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Nothing has changed since I last used it in Virginia a couple months ago. Even without setting up the root folder properly, I should be able to calculate new filters without an issue.


Hi,
A quick answer.
You should not use a space in any names of folders and files for Workshop
The problem is with "All Speakers" folder.
Sorry for this "old school" requirement ... : )


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi,
> A quick answer.
> You should not use a space in any names of folders and files for Workshop
> The problem is with "All Speakers" folder.
> Sorry for this "old school" requirement ... : )



Time to upgrade to Apple computers.


----------



## captainobvious

Raimonds said:


> Hello Friends,
> 
> 
> 
> Some time ago I mentioned that it is very tricky to use FIRs to create a multi way system ? to create a crossover.
> Here is a solution ? the software called C5.
> The software is offering all the necessary management to operate the multi way system.
> It allows to exploit a power of FIR to create an ideal crossover. Why ideal?
> Because it incorporates correction for each particular band/way.
> 
> 
> 
> Take a look on some screen shoots and results.
> The system ?under test? was large PA with some bands already with acoustic filters (band pass). It is almost impossible to tune ordinary dsp for work with such system.
> But the use of correction on each particular band allows to use very delicate crossover (LR24), get very low crossover?s group delay, as result, and possibility to correct it by sacrificing only 12 ms of latency.
> APL has idea to create a 10 channel unit for DSP use ? 4 channels with 8192 taps,6 channels with 4096 taps. For use as 5 way DSP or 4 way DSP with master EQ on its input.
> 
> Please vote, is such unit necessary or not?



I would love to see a product like that from you. Also, the point about needing a volume control for digital sources is a good one- we would need that too.
I'm very interested in this Raimonds.

Thanks


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thank you very much for your thoughts!

I must express, that this solution is ready to use right now by screwing together as many PCBs of APL1 as many ways you would like to have.

It will be not so elegant as one PCB of future 10 channel unit, but will work right now! The stack is 75 mm in high.














fullergoku said:


> yes its needed!! would the VST plugin be available before the hardware example?


It is available right now!
As you can see from screen shoot, C5 works with stereo “units”. That units can be plugins.
It means you can use 4 plugins in 4 busses of your DAW to create 4 way system.
Only fir file update will be not so elegant – you will need to go to each of plugins to set new files after some changes in C5.



neoysj said:


> Yes 100% necesary
> it will be good also if there is the possibility of custom crossover


The possibilities of “custom” are limited only by your imagination : )



LumbermanSVO said:


> Being able to add a physical volume knob would be wonderful. Then I could go digital from my phone, into the processor, then amps. No head unit, no extra doodads, and I wouldn't have to try and track down a couple of old Audio Control MVC's.


Yes, good idea!


----------



## fullergoku

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Thank you very much for your thoughts!
> 
> I must express, that this solution is ready to use right now by screwing together as many PCBs of APL1 as many ways you would like to have.
> 
> It will be not so elegant as one PCB of future 10 channel unit, but will work right now! The stack is 75 mm in high.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> It is available right now!
> As you can see from screen shoot, C5 works with stereo “units”. That units can be plugins.
> It means you can use 4 plugins in 4 busses of your DAW to create 4 way system.
> Only fir file update will be not so elegant – you will need to go to each of plugins to set new files after some changes in C5.
> 
> 
> The possibilities of “custom” are limited only by your imagination : )
> 
> 
> Yes, good idea!


Raimonds I was looking but couldn't find a site or download to take a look at the C5 software do you have a link or webpage for it?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

What kind of DAC and ADC are used in the APL1?

My suggestion for future product improvement would be to use top quality DAC chips, like a ESS Sabre.

The software interface could use more detailed instructions on use.

More filter taps would be nice.


Sent from my iPhone using Tapatalk


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Will your new units be able to implement crossovers? To me this is basic functionality and almost makes it expensive/waste to buy a DSP just to use for crossover duty with an APL1.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



fullergoku said:


> Raimonds I was looking but couldn't find a site or download to take a look at the C5 software do you have a link or webpage for it?


All APL1 customers are welcome to evaluate and use C5.
Please send inquiry!
I forgot to mention that it may help even you have just one unit.
C5 is next after C1 to implement targets, delays, gains



dgage said:


> Will your new units be able to implement crossovers? To me this is basic functionality and almost makes it expensive/waste to buy a DSP just to use for crossover duty with an APL1.


APL1 unit, as it is right now, is able to serve crossover function with help of C5 as management.
But you must use multiple units (PCBs) as many ways/bands you have.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hey Raimonds, i sent you an email. Needing some help with setup. getting some errors. Maybe we can teamviewer?


----------



## Weightless

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I just got mine in today. Hopefully I'll be able to play with it this week...

Skizer, keep us updated on how it goes.

Sent from my SM-N920P using Tapatalk


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Steve (captain obvious) was kind enough to talk to me on the phone today for about an hour and a few texts to walk me through. i understand how it all works now and its rather simple-ish once you know what bottons you need to click and in what order. i still have a few problems

1) i need my mic calibration files converted to be used in the workshop software (raimonds is taking care of that)

2) for the APLconfig_v6.3_s driver x64, I cannot install it on Windows 8 properly. It keeps failing. it might just be the POS laptop though

3) I can run it fine on my windows 7 laptop. But it only has 2 usb inputs so I can't connect my Mic, the unit, and the usb stick at the same time. Do I have to have all 3 connected at the same time or is there a work around?

i think i found a work around. its a pain, but itll have to work. i would have to leave the usb stick that i have it all saved to in. do the measurements in workshop, unplug my mic, open up the APLconfig_v6.3, then upload and write the FIR files


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> What kind of DAC and ADC are used in the APL1?


It is CS4270 codek from Cirrus Logic.



> My suggestion for future product improvement would be to use top quality DAC chips, like a ESS Sabre.


Very long "life" of APL1 is showing that there is no "short" in converters.
The APL1s should be considered for applications that require wider dynamic range.



> The software interface could use more detailed instructions on use.


The professionals are not reading manuals usually : )
APL solutions are for professionals ...



> More filter taps would be nice.


Please show me the case when it is short : )
Taps are very expensive. They should be used rationally.
The large number of available taps is not giving any value
like 32 channel mixing console if you are using just 4 channels.

Same time, the large number of filter taps means long Impulse Response of filter in time domain. Which means - smearing.
The length of filters must shortest possible that is doing necessary job.


----------



## Weightless

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> Steve (captain obvious) was kind enough to talk to me on the phone today for about an hour and a few texts to walk me through. i understand how it all works now and its rather simple-ish once you know what bottons you need to click and in what order. i still have a few problems
> 
> 1) i need my mic calibration files converted to be used in the workshop software (raimonds is taking care of that)
> 
> 2) for the APLconfig_v6.3_s driver x64, I cannot install it on Windows 8 properly. It keeps failing. it might just be the POS laptop though
> 
> 3) I can run it fine on my windows 7 laptop. But it only has 2 usb inputs so I can't connect my Mic, the unit, and the usb stick at the same time. Do I have to have all 3 connected at the same time or is there a work around?
> 
> i think i found a work around. its a pain, but itll have to work. i would have to leave the usb stick that i have it all saved to in. do the measurements in workshop, unplug my mic, open up the APLconfig_v6.3, then upload and write the FIR files


Why not just load the software on the W7 machine? Now You have just enough usb ports for the mic and unit...

That is what I will have to do with mine since I am limited as well on my Sony Duo11.

Sent from my SM-N920P using Tapatalk


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Weightless said:


> Why not just load the software on the W7 machine? Now You have just enough usb ports for the mic and unit...
> 
> That is what I will have to do with mine since I am limited as well on my Sony Duo11.
> 
> Sent from my SM-N920P using Tapatalk


it would just make things easier. 
oh, i also have a few more problems. 

4) when the unit is in "bypass" mode, i still get no sound through the coaxial input. 

thats all i can remember at the moment


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> 2) for the APLconfig_v6.3_s driver x64, I cannot install it on Windows 8 properly. It keeps failing. it might just be the POS laptop though


Maybe you've tried already, but I find with most windows 8/10 you have to run installation with Administrator privileges? (All windows updates current? And its an x64 laptop, not x32?)

Frustrating when things don't go smooth.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> Steve (captain obvious) was kind enough to talk to me on the phone today for about an hour and a few texts to walk me through. i understand how it all works now and its rather simple-ish once you know what bottons you need to click and in what order. i still have a few problems
> 
> 1) i need my mic calibration files converted to be used in the workshop software (raimonds is taking care of that)
> 
> 2) for the APLconfig_v6.3_s driver x64, I cannot install it on Windows 8 properly. It keeps failing. it might just be the POS laptop though
> 
> 3) I can run it fine on my windows 7 laptop. But it only has 2 usb inputs so I can't connect my Mic, the unit, and the usb stick at the same time. Do I have to have all 3 connected at the same time or is there a work around?
> 
> i think i found a work around. its a pain, but itll have to work. i would have to leave the usb stick that i have it all saved to in. do the measurements in workshop, unplug my mic, open up the APLconfig_v6.3, then upload and write the FIR files



Happy to help buddy.

BTW- It's ok that your laptop only has 2 usb ports. You only need one of them to do the measurement of your system. If you want to be connected to the DSP Pro at the same time so you can make adjustments based on your measurements in Workshop (or TDA), then you're still fine. You don't need to be connected to the APL1 for this portion. AFTER you get your basic crossovers and time alignment set using TDA and Workshop, you measure the system in Worskhop and then you are done with needing that usb port for measuring. You can then apply corrections and targets in Workshop and generate new fir filters based on the original measurement. You can then simply use that second usb port to be connected to the apl1 via APLconfig to upload the fir filters to the L and R channels and define presets. You can also use the C1 programs to generate new target curves and apply those curves to the live preset.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds was also kind enough to teamview with me to make sure I was doing everything correctly and showed me a few tips and tricks. Initial measurement and tune with no eq on the helix, only ta and crossovers... I need to do some more practice lol

Sent from my VS988 using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


>





Raimonds said:


> ...
> C5 is next after C1 to implement targets, delays, gains
> 
> APL1 unit, as it is right now, is able to serve crossover function with help of C5 as management.
> But you must use multiple units (PCBs) as many ways/bands you have.


Hi Raimonds,
Do you have higher resolution screenshots of C5?
I understand it can manage XO, TA and then EQ all in one, but I’m curious about the real life workflow.
For example the method for sweep measurements of 8 drivers, and if it's 200+ points here too.
Thank you!


----------



## Inese_APL

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Hi Raimonds,
> Do you have higher resolution screenshots of C5?
> Thank you!



On Acoustic Power Lab facebook page you can find a picture more clear (can not add link...new here...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Inese_APL said:


> On Acoustic Power Lab facebook page you can find a picture more clear (can not add link...new here...


Good thank you, no FB for me but I found it, that helped.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Hi Raimonds,
> Do you have higher resolution screenshots of C5?
> I understand it can manage XO, TA and then EQ all in one, but I’m curious about the real life workflow.
> For example the method for sweep measurements of 8 drivers, and if it's 200+ points here too.
> Thank you!


Hi,
Sorry for improper resolution. I have uploaded files in native resolution
but some kind of resizing happened here.
Yes, you need to sweep each way/band.
The number of points depends on environment and driver construction.
You can use even 1 point if your driver is ideal in terms of directivity.
That does not happen in real life.
The number of points should be 25 ... 100 when working with TDA EQ in pretty much free room.
The number of points should be 100 ... 200 when working with Workshop in a car environment.
But, even 100 points take just 33 seconds of time ...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Interesting, TDAeq works differently than workshop (I never used last version, that is I think the one that can create filters too).
Ok so I guess less points under the Schroeder frequency and normal above.

I wasn't so much worrying about the amount of points, but just curious about the workflow.
Like, do we measure each pair independently like for regular L/R with APL1, then go to the next pair etc.
Or can we measure anything as we want, maybe even all in one session (following lw/rw/lm/rm/lt/rt for ex).

And curious too especially about the way to integrate everything with the master EQ.
But based on the screenshots it seems easy, with the help of tda to finetune delay etc.
And do we define master eq on all corrected pairs' response, or is there a way to create all filters at once?
Thank you!


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Probably a stupid question, but using TDA does it give you the delay values and you put in your DSP or is it applied in the workshop before the DSP... and do you take measurement from single location (headrest) like a normal TA measurment? :blush:


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Interesting, TDAeq works differently than workshop (I never used last version, that is I think the one that can create filters too).
> Ok so I guess less points under the Schroeder frequency and normal above.
> 
> I wasn't so much worrying about the amount of points, but just curious about the workflow.
> Like, do we measure each pair independently like for regular L/R with APL1, then go to the next pair etc.
> Or can we measure anything as we want, maybe even all in one session (following lw/rw/lm/rm/lt/rt for ex).
> 
> And curious too especially about the way to integrate everything with the master EQ.
> But based on the screenshots it seems easy, with the help of tda to fine tune delay etc.
> And do we define master eq on all corrected pairs' response, or is there a way to create all filters at once?
> Thank you!


Ok! The workflow should be such:
1) measure each speaker for each way, 8 measurements for 4 way system,
2) add respective measurement .fir files (already in form of corrections)
to the main tab of C5
3) take a look on performance of each way and chose crossover points in the Curves tab of C5
4) create the crossover in the tab "Crossover", activate it by respective
checkboxes in the Main tab, upload results to units,
5) measure overall systems performance by use of TDA to adjust crossover levels, delays, phases. The crossover time correction would be used to
make delay settings more straight forward.
6) measure overall systems performance by use of TDA EQ or Workshop to create final detailed EQ. Add it as a master into C5.
7) chose some target in the PEQ tab, activate it on the Main tab,
upload all firs to units. You are ready to go!



crackinhedz said:


> Probably a stupid question, but using TDA does it give you the delay values and you put in your DSP or is it applied in the workshop before the DSP... and do you take measurement from single location (headrest) like a normal TA measurment? :blush:


You can get delay values for DSP adjustment by use of TDA software


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> The professionals are not reading manuals usually : )
> APL solutions are for professionals ...


I am a pro LED video guy who actually reads manuals, when I saw all the "Send" buttons in the C5 software it just reconfirmed that you usually work in a pro environment. Perhaps that is why I was able to learn the software quickly..

Also, I'll be emailing you soon so I can take a look at the C5 software...

Roughly how much would it cost for an enclosure with 4 boards in it, for a 4-way system?

If you can make a compact system capable of 4-way outputs, I'll be your first buyer.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sounds good thank you Raimonds, seems very impressive.
Can we define/upload to c5 some targets per individual driver?
kind of like the master target in regular apl1, txt file or anything else.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Right now, the most compact version is stack of 4 PCBs 75 mm in high.
The all in one board 10 channel unit is a dream.
I am thinking about some kind of "kickstarter" project.
But it is too much business management for an engineer to do that.

The target or parametric eq can be used for each particular unit/driver/way
and for all system as master.
You can use ordinary parametric EQ interface and/or input as a curve in form of txt file.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Finally have my VST working, using through Foobar for now...

Anyway, I was having a little issue with my measurements not loading correctly so I sent to Raymond and he fixed for me, and believe he applied M1 curve(?). Two questions:

Which Mic calibration file should I use for making corrections, mic pointing straight ahead, but sweeping across winshield and up/down, is it 0 degree, 45 or 90 degree? Because sometimes the sweep covers all the above...

Also, I needed to turn the vst overall gain down -6db and it gets loud very quick, my volume control is 0-100. It gets loud at 20, does this indicate a need to lower my amp gains instead?


So far it sounds great! Much better than I could ever do by ear, myself. I still have to re-measure and try other curves, but I'm so impressed.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is it a umik-1?
If so pointing front I would probably use 45 degree as it should be the most representative.
When I had mine I used to point up with the 90 deg file, as 80% of the sweeps were measured mic up.
Anyway it should not make a big difference, few dbs high up only, you could finetune later with the target if needed.

For the gain on vst I have no idea.
Is it some kind of target level or just the volume control?
Louder after the filter would be strange, as it should mostly cut.
But that depends of the measurements, or of what settings Raimonds used to create the filters.

Maybe check the difference between predicted/measured, I used the biggest gap as reference for my output level (or target range) to avoid or minimize clipping.
Even if curves are smoothed and so mask a little, it gave good results.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks, it is a UMIK-1. I will use the 45 degree.


As for the VST level, I am referring to this screen (not sure if everyone with APL1 uses this or just vst on PC):












I had to lower the input level a lot and it gets loud a lot sooner than I'm accustomed to. Im thinking my amp gains should be lowered instead of the vst, theoretically that would be better for maintaining head room as well as less overall stress on the amp, am I correct in this assumption? 

Thanks for the advice, hopefully I can get some free time tomorrow.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Yes, everything is about headroom. We have zero headroom in recordings because of "loudness war". And we must restore it. Only right place to do that is input level control of plugin. You must lower it till there is no clipping. There is no reason to reduce gain of amplifiers. It may be necessary to increase it in some cases.
The amount of gain reduction may be 10 ...12 dB in some cases. It depends how deep correction you have.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds-

I have a few questions for you after using the software for a while and after re-reading through the QSG.

1. In APL Workshop, you have the "Low Frequency Limiter" and "High Frequency Limiter". My understanding is that these adjust the amount of available EQ boost when the APL1 is making corrections. Does this also limit the amount of eq *cut* by the same amount? Is 0db the maximum amount of boost/cut?
Also, what determines the frequencies affected by the Low Frequency Limiter and High Frequency Limiter? What are those frequency ranges which are considered Low and High?

2. You state in the QSG that when doing initial measurements/corrections (without target) that the system may lose low frequency response and this can be corrected by changing the time window (or adding in response with target curve).
Can you instruct how to change the time window? I see there are "Time Window Files" that can be selected but I'm not sure how each one affects the time window. 
*EDIT: Found the answer to this.*
_“Time window file” – to browse for time window file. Time window files are stored
in TW folder. First 3 symbols in filename represents it length in ms. Next frequency
value roughly represents lowest frequency for accurate analysis. You can see the time
window curve in the Impulse Response tab of the Graphs window._

3. Further to question number 2, what is the best process for trying a composite correction when doing car measurements?

4. If no target curve or correction curve is used (and assuming we have a proper time window to convey accurate LF response in the measurements), does the .fir file generated simply correct for minimum phase without altering the response shape?



Thanks.

-Steve


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks for questions, Steve,

1. "Limiters" are for controlling the gain of EQ in out of bands regions - very low and very high frequencies. When equalizer (correction) curve meets the "limit" value it will not grow more and keeps the limit value for all "out of band" frequency range.
You can see the effect of they work as flat curve parts.
EQ can offer almost any cut and boost amount. But you must use that with care.
3. "Composite correction" was developed for pro use when we have some number of loudspeakers on same line and must use same EQ for all of them.
You can increase the accuracy of correction by making some number (3 for example) of measurements for same loudspeaker and then use Composite to make a final measurement.
4. The use of correction or target curve is very simple in Workshop.
They are just subtracted from actual measurement curve.
If you are not using any correction or target, nothing is subtracted and measured curve is directly used for creation of EQ.

Please use "View as EQ" check box time to time to feel better what will be the final EQ.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have to say that after using the APL VST my system has never sounded better! 

My first time ever hearing an SQ car was at the NC gtg a couple years ago, and I was lucky enough to hear Claydo's car. Anyone who has ever heard it knows he plays at intense levels, and is very dynamic! After hearing his, I was hooked. That is the sound I am after, and finally feel like I'm getting so close.

After taking several measurements and tinkering with my own custom EQ curves I finally feel like I'm sitting in Clays car. Well almost! But the instruments finally sound super realistic and dynamic. The impact everyone always talks about, I never could achieve with REW. Instantly, APL worked its magic! and I'm a believer.

Thank you Raimonds. A++ 


I'm pretty sure my first attempt at the workflow left room for improvement, so if it sounds this good now I cannot wait to try again! Also I'm using the VST plugin through Foobar2000, but Foobar is not very CarPC friendly so in the future I want to get it working with Centrafuse.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hello,
> 
> I will try to explain how to use additional „near on axes” measurement to make the correction result more accurate for „on axes” position in case when loudspeaker has a pretty strong directivity in some frequency band.
> 
> 1.	You should make an „ordinary” Power Response measurement by collecting measurement points in full wide angle or volume.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 2.	You should make an additional „near on axes” measurement by collecting measurement points in relatively small square, about 20 x 20 cm, on axes.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 3.	Let’s calculate the curve that is representing an effect of directivity by subtracting our first curve from the second one by setting the first one as „correction” for the second one.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 4.	Let’s smooth it
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 5.	Let’s remove LF part by flatting it (by use of „Limiter”).
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 6.	Let’s make the correction for first measurement by adding the smoothed and edited directivity curve as „correction” for first measurement but by using „INV” check box because we need to add it, not subtract.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Now we have the measurement curve and, of course, the equalizer curve that do not boost up frequencies that are emitted in narrow beam on axes.


Raimonds, this was a post of yours at beginning of this thread and I have a question as it seems the pictures you provided no longer display so I was uncertain of this process...

I am using 3" wideband 400Hz-20k, when subtracting your first measurement from the 2nd (on axis), which file do you select to use as the "correction" file, the .data, .FIR, .wav? 



Also I experience a weird bug(?) when running a measurement in Workshop. I measure the left side, all goes well. but when I measure Right side the pulsating stutters, and only proceeds if I turn the volume 'Up'. (No matter how gains are set). You would think if it was clipping turning the volume up would make it worse but thats when it runs fine after that. 

Do you think the volume difference for Right vs Left side measurement will cause any issue with the calculations? Sounds good to the ear! 

Thanks


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Anybody here using the Foobar VST plugin? I'm having a hard time keeping any presets? I load the .FIR files and apply settings, but several uses later the extra presets I add seem to disappear.

Is there a central location (Folder) that keeps presets for VST plugin?


----------



## strohw

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Anybody here using the Foobar VST plugin? I'm having a hard time keeping any presets? I load the .FIR files and apply settings, but several uses later the extra presets I add seem to disappear.
> 
> Is there a central location (Folder) that keeps presets for VST plugin?


Try using Equalizer APO to setup your convolution and then you can use whatever player you want to use.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks! I will look into this.

Am I correct in thinking I do not need a virtual audio cable or even a VST host to use APO equalizer?


----------



## strohw

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> Thanks! I will look into this.
> 
> Am I correct in thinking I do not need a virtual audio cable or even a VST host to use APO equalizer?


You shouldn't need a VST host if you are only trying to play a convolution filter. APO support .wav filters out of the box. In regards to virtual cable, what were you using it for? The mixer in APO is pretty good but would need more details.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



strohw said:


> You shouldn't need a VST host if you are only trying to play a convolution filter. APO support .wav filters out of the box. In regards to virtual cable, what were you using it for? The mixer in APO is pretty good but would need more details.


I'm just trying to play the APL vst (.FIR) from Windows 10, everything I could find on VST mentioned needing a virtual audio cable...but I was unsuccessful getting any audio out. Foobar vst plugin works, but foobar is kind of a pain on a 7" CarPC, so I have been looking for a Windows system level audio solution, and I think you just provided what I was hoping for.

I like using Centrafuse, so being able to use and output my APL sound is what I'm after.

Thanks!


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds ,

Got a question for ya, 

How does apl work with combfilters caused by interaction from opposing channel drivers vs standard 1/4 wave reflection nulls? 

I've made a filter that is the inverse phase of each driver at 1st and 2nd comb with excellent success , brought a -20db deep notch up to -8db and a -10db notch fully recovered to less than -3db . Just curious how your system works a little more now. 

I understand the TDA software shows timing per driver , but it doesn't show a stereo (2ch) analysis to see interaction between channels. Or does it? 

Are you correcting reflection or do you also correct interaction issues as well?


Btw: I'm still not 100% on board with Apl , but if you do make a 4 way box I would have to give it a try. That would be cool.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi,
It is highly not recommended to equalize narrow nulls.
You must not see them in your measurement normally.
But, if you see, 1) you should double check your measurement method/process
2) you should try to fix the loudspeaker's problem creating narrow null
Here you can read more about that:
http://aplaudio.com/downloads/Equalizing_loudspeakers.pdf
Acoustic Power Lab :: Knowledge Base


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi,
> It is highly not recommended to equalize narrow nulls.
> You must not see them in your measurement normally.
> But, if you see, 1) you should double check your measurement method/process
> 2) you should try to fix the loudspeaker's problem creating narrow null
> Here you can read more about that:
> http://aplaudio.com/downloads/Equalizing_loudspeakers.pdf
> Acoustic Power Lab :: Knowledge Base


Hi Raimonds,

I wasn't talking specifically about "equalizing" nulls. For one I wouldn't waste your time with such nonsense. 

I read your articles and even your articles touch on the subject and suggest all kinds of solutions but never really speak to what it does to make the correction I'm trying to ask but it's not relevant to car and the article is geared to a hall.

So maybe a misunderstanding there. No worries I'll try to ask in a different manner and number your contraindications.


1. The type of interference can be measured but only as a summed average of two channels (unless you know of a measurement technique I don't) as we are usually measuring single speakers or single channels. Now as a stereo off center measurement would be riddled with errors. But the effects of the primary question are seen in a averaged FR measurement of both channels and the effects can be largely predicted based on PLD and known variables and there effect on frequency when delay is introduced against a opposing channel.. 

So, I get what apl is doing as far as corrections in TDA as a single channel , maybe in a 4way , we would say the 4 right speakers. And the corrections it does to get the time domain made linear for that channel. 

So, the question I have is in a car we don't sit in the center ( 2. Can't move the speakers to adress nulls or move the seats for that matter) , let's say one was to use apl and TDA and make a correction for both channels , targeted for one seat only. 
Now the user has added let's say a 1.3ms delay on the left side to get better timing for that seat for two channel audio. (2way, 3way,4way don't care same question) 

That delay will cause combfilters when the two channels interact, as frequency and delay are not linear. (Ex. Path length difference of 3.2rad @384hz) 
So with that said a few nulls and peaks develop, 
My question is what does APL do to adress this? To make the question even easier let's say we forget about the two narrow nulls in the comb and only do something about the wider more manageable null. 

So I think I've addressed all of your contraindications 

I was curious how APL handles delay between channels. if the delay becomes a part of the correction and the combfilter effects on frequency with a PLD delay is even figured into the correction. If it is, than I would be extremely interested in trying APL. If it's not because you think nothing should be done with combfilters that's also an answer. So I'm not pinning you against a corner nor saying one answer is better. Simply asking if APL addresses this or not. 

Thx


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi,
The target for use of APL solutions is for the loudspeaker, the loudspeaker system, the one particular channel of sound reproduction.
And it is not a hall, a room or other environment.
same time, there are some solutions for room/hall in development and testing stage.

"Now as a stereo off center measurement would be riddled with errors." - there is no such problem. All work is focused on one loudspeaker/channel
Same time, you can treat a stereo system as one, which is containing two drivers. And there is no problem to measure it as one.


"And the corrections it does to get the time domain made linear for that channel" - yes


"Now the user has added let's say a 1.3ms delay on the left side to get better timing for that seat for two channel audio. (2way, 3way,4way don't care same question)

That delay will cause combfilters when the two channels interact, as frequency and delay are not linear. (Ex. Path length difference of 3.2rad @384hz) "

- lets return to papers. You will have same situation when you sit in front of some stereo system and slightly move from one side to another. What is happening with sound? Nothing! The sound source image is just slightly moving with you.
Therefor - there is no such problem as you described.

"I was curious how APL handles delay between channels." - as already described, no need to be worry about that as the focus is on each particular channel/loudspeaker.

BR,
Raimonds


----------



## dgage

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Raimonds- You mention the comb filters at different frequencies. This is his point, there will be some issues when two channels come together in a car even if both channels are optimized individually. He wants to know how can the APL1 best be used to align both channels (L/R) to get the best sound in a car for one seat, the driver?


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi,
> The target for use of APL solutions is for the loudspeaker, the loudspeaker system, the one particular channel of sound reproduction.
> And it is not a hall, a room or other environment.
> same time, there are some solutions for room/hall in development and testing stage.
> 
> "Now as a stereo off center measurement would be riddled with errors." - there is no such problem. All work is focused on one loudspeaker/channel
> Same time, you can treat a stereo system as one, which is containing two drivers. And there is no problem to measure it as one.
> 
> 
> "And the corrections it does to get the time domain made linear for that channel" - yes
> 
> 
> "Now the user has added let's say a 1.3ms delay on the left side to get better timing for that seat for two channel audio. (2way, 3way,4way don't care same question)
> 
> That delay will cause combfilters when the two channels interact, as frequency and delay are not linear. (Ex. Path length difference of 3.2rad @384hz) "
> 
> - lets return to papers. You will have same situation when you sit in front of some stereo system and slightly move from one side to another. What is happening with sound? Nothing! The sound source image is just slightly moving with you.
> Therefor - there is no such problem as you described.
> 
> "I was curious how APL handles delay between channels." - as already described, no need to be worry about that as the focus is on each particular channel/loudspeaker.
> 
> BR,
> Raimonds



Thanks for the reply. 

The curiosity of trying APL is almost at it peak with me now. 
Just in terms of its approach. And how it handles timeing errors. 

From what your saying once each stereo channel has been corrected and exhibits a uniform TDA from the same mic location as the left than the time of travel delay will be worked out automatically. Meaning the user need not add any further signal delay because all time of flight delay is factored into the measurement/s 

As far as taking measurements of a stereo set of speakers simultaneously, you must know of a measurement technique I am unaware of. As far as I know I can only see usable phase data on one side at a time.  
Diffrent subject maybe another conversation. 

So a few months ago I emailed you and got a link for a trial on APL workshop and TDA. 
I hope those links are still valid. I am very curious now to fiddle with it some. 
I've just been very reluctant to spend the time going through a learning curve and wanted to master the equipment I use now first. So I think I'm ready to try and at least give it a honest review and maybe purchase if the results are repeatable and fast. 

Thanks, 




dgage said:


> Raimonds- You mention the comb filters at different frequencies. This is his point, there will be some issues when two channels come together in a car even if both channels are optimized individually. He wants to know how can the APL1 best be used to align both channels (L/R) to get the best sound in a car for one seat, the driver?


Precisely


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> So a few months ago I emailed you and got a link for a trial on APL workshop and TDA.
> I hope those links are still valid. I am very curious now to fiddle with it some.
> I've just been very reluctant to spend the time going through a learning curve and wanted to master the equipment I use now first. So I think I'm ready to try and at least give it a honest review and maybe purchase if the results are repeatable and fast.


If it helps, TDA is easier to get up and running than Workshop.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> If it helps, TDA is easier to get up and running than Workshop.




Not true.

I can’t get TDA to open because it says it can’t be installed on the primary drive?


Sent from my iPhone using Tapatalk


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

My TDA is installed on the same USB stick I have the other APL applications on. Each has its own folder on the root of the USB drive.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Ah. Ok will try that.


Sent from my iPhone using Tapatalk


----------



## Babs

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> My TDA is installed on the same USB stick I have the other APL applications on. Each has its own folder on the root of the USB drive.



Captain I’d love a little TDA “101” class if possible next time we meet up maybe. I have it and have measured with it, but obviously have some holes in my skills on how to properly use it and make prudent TA adjustments with it. 


Sent from my iPhone using Tapatalk Pro


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> If it helps, TDA is easier to get up and running than Workshop.


Ha I had a hell of a time getting matlab to work. 
I got TDA downloaded for trial, I'm going try and make a go at it this weekend. 

I got to look more on Raimonds site for the workshop download for trial.

Looks like I need jriver to convolution. 
I'll give it a go. 
Very unique approach. The TDA looks very promising even I don't use use the APL box. But I want to try and do it the way it's meant to go and listen to it. 

I've been on different fourms heard all kinds different ways. 
I'm not sold one way or other , **** I'll try anything for fun.
But for car this is intriguing. The more I figure out how how this all goes together.


----------



## forty5cal1911

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Can anyone confirm that my understanding is correct.

I am running a Windows 10 tablet as a source to the Helix HD-USB card. Since Foobar2000 supports VST Plugins, it appears I can use the APL1 in software.

In order to do so all I will need is the APL Workshop software as well as the APL EP1 VST Plugin is that correct?

This will allow measurement, correction and export of the corrected .fir files for use in the VST plugin is that correct?

Thanks for any help!


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Your understanding is correct. The use of the windows machine, running a program that supports plugins, means you already have the capable hardware to run the software, and execute the eq. As far as the specifics of running your setup this way, I'm not experienced in the process, as I run the apl hardware.......but I believe user crackinhedz would be a good one to contact, if he doesent respond here. I believe he's running a simular setup.


----------



## forty5cal1911

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Your understanding is correct. The use of the windows machine, running a program that supports plugins, means you already have the capable hardware to run the software, and execute the eq. As far as the specifics of running your setup this way, I'm not experienced in the process, as I run the apl hardware.......but I believe user crackinhedz would be a good one to contact, if he doesent respond here. I believe he's running a simular setup.


Thanks Claydo! I'll ping crackinhedz with a few questions.

Think I'm going to reach to Raimonds and see if I can buy the Plugin and Trial the Software for testing.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have to say, I love the APL.

But, my experience with the VST has not been very ideal. First, foobar2000 works perfect with the VST, but I hate foobar2000 as my media player...not very carpc friendly, small text etc. I prefer to use centrafuse, but have not found a stable way to apply VST to the windows audio. Ive searched the web, tried Virtual Audio Cable, VST hosts etc. but I come up short and cannot figure it out. The closest Ive come is using Equalizer APO which outputs the VST on the main Windows 10 audio level. But it has this weird click noise when applying the VST, so another roadblock for me unfortunately...

If I had to do it again, I would just go with the hardware APL-1 unit, not the vst. But if youre super computer savvy you might have better luck.

I love the APL sound, I just seem to have compatibility issue on my end trying to use the VST. ?


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I have yet to been able to get my apl to actually do anything besides cause clipping. Haven't touched it in a few months but will be re-doing my amp, sub, and dsp install soon and will play with it again when that time comes 

Sent from my SM-G950U1 using Tapatalk


----------



## forty5cal1911

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> I have to say, I love the APL.
> 
> But, my experience with the VST has not been very ideal. First, foobar2000 works perfect with the VST, but I hate foobar2000 as my media player...not very carpc friendly, small text etc. I prefer to use centrafuse, but have not found a stable way to apply VST to the windows audio. Ive searched the web, tried Virtual Audio Cable, VST hosts etc. but I come up short and cannot figure it out. The closest Ive come is using Equalizer APO which outputs the VST on the main Windows 10 audio level. But it has this weird click noise when applying the VST, so another roadblock for me unfortunately...
> 
> If I had to do it again, I would just go with the hardware APL-1 unit, not the vst. But if youre super computer savvy you might have better luck.
> 
> I love the APL sound, I just seem to have compatibility issue on my end trying to use the VST. ?


Thanks for the feedback! Definitely useful. And yeah.... foobar on a tablet especially with a custom skin not friendly at all.

Have you tried JRiver Media Center? Supposed to be the best and has some very advanced VST plugin capabilities but I have not used it. Thinking that if it works more reliably that may be the ticket. Anybody have any experience with it?


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So essentially, I can get a base measurement and apply EQ curves, which sounds awesome. But I am unable to take additional measurements to fine tune it.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



forty5cal1911 said:


> Thanks for the feedback! Definitely useful. And yeah.... foobar on a tablet especially with a custom skin not friendly at all.
> 
> Have you tried JRiver Media Center? Supposed to be the best and has some very advanced VST plugin capabilities but I have not used it. Thinking that if it works more reliably that may be the ticket. Anybody have any experience with it?


I did try JRiver (trial), which has a sweet GUI but it did not play nice with the VST. It did this strange thing where no matter what my volume was set at, it would output the sound at ear screetching levels, scary to say the least...so I abandoned that idea.  There are a crap ton of options and settings, perhaps I did something wrong, who knows.

I consider myself to have a pretty good understanding of Computers, but this just baffles me.


----------



## forty5cal1911

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> So essentially, I can get a base measurement and apply EQ curves, which sounds awesome. But I am unable to take additional measurements to fine tune it.


What seems to be preventing you from taking additional measurements and applying?

Sorry for all the questions just want to thoroughly understand what I may be getting myself into here.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> I have yet to been able to get my apl to actually do anything besides cause clipping. Haven't touched it in a few months but will be re-doing my amp, sub, and dsp install soon and will play with it again when that time comes
> 
> Sent from my SM-G950U1 using Tapatalk



Nick, sounds to me you need to reduce the source level into the apl. Unlike our manual eq world we've grown accustomed too, using only cuts and supplying the eq with the strongest possible signal, the apl needs room within the signal to boost as well as cut as it sees fit. Most of us ran into this issue, and once the input is low enough for the apl to work without clipping, all is beautiful......lol.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Nick, sounds to me you need to reduce the source level into the apl. Unlike our manual eq world we've grown accustomed too, using only cuts and supplying the eq with the strongest possible signal, the apl needs room within the signal to boost as well as cut as it sees fit. Most of us ran into this issue, and once the input is low enough for the apl to work without clipping, all is beautiful......lol.


It's digital coax in. I can't 

Sent from my SM-G950U1 using Tapatalk


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



SkizeR said:


> It's digital coax in. I can't
> 
> Sent from my SM-G950U1 using Tapatalk


Oh....well, there is a procedure for lowering the input gain...me thinks,in the software, if I remember correctly......I think subterFUSE or raimonds can help ya. I'd have to look back, but I believe it's outline in this thread somewhere......unless I'm trippin......it has happened.....lmao.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Oh....well, there is a procedure for lowering the input gain...me thinks,in the software, if I remember correctly......I think subterFUSE or raimonds can help ya.


already had raimonds spend a few hours with me via team viewer running through everything. still nothing out of it. Like i said, i will try again with analog inputs and outputs when i re-do that part of my install


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Oh.....damn.....hate that for ya, better results with the analog ins, I hope.


----------



## SkizeR

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> Oh.....damn.....hate that for ya, better results with the analog ins, I hope.


hopefully. not sure if i was doing something wrong, but i confirmed my process with 3 people including raimonds.


----------



## crackinhedz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



forty5cal1911 said:


> What seems to be preventing you from taking additional measurements and applying?
> 
> Sorry for all the questions just want to thoroughly understand what I may be getting myself into here.


When I use APL workshop, it will output the measurement sound through windows level audio output. But, after I obtain the FIR filter, I cannot apply it to my windows system level audio for repeat measurement. 

So, I have just been using the base measurement with EQ applied through Foobar. Sounds really good so Im still happy, I just cannot fine tune it.

Im not really knowledgable with VST host and virtual cables, so I tried to understand using the internet...I just seem to come up short...you may have bettet result.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

https://static1.squarespace.com/static/55c8a274e4b09cb562cd3ea0/t/59f8871ce2c48368e55848d7/1509459746804/How+to+Obtain+a+Good+Stereo+Sound+Stage+in+Cars.pdf

How does this compare with what APL1 does. Does APL1 filter do this as well since it is measuring in the area between the passenger and driver as well?


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

FYI- I had the same thing happen with an APL when trying to use the digital in/out. It worked fine for analog, but it wouldn't output via digital out. Didn't matter if it was analog in to digital out or digital in and out. 

I use mine analog so it wasn't a big deal for me, but for others that is a concern and I'd wait to find out how to get this to work before ordering.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> FYI- I had the same thing happen with an APL when trying to use the digital in/out. It worked fine for analog, but it wouldn't output via digital out. Didn't matter if it was analog in to digital out or digital in and out.
> 
> I use mine analog so it wasn't a big deal for me, but for others that is a concern and I'd wait to find out how to get this to work before ordering.


Did you try both the digital outs? The analog and ONE digital out is always working. The internal jumper is for what digital out is working, optical or coax.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi Friends,

It is known issue with Full Scale digital signal - no headroom for any kind of processing.
You must create a headroom by reducing signal level.
The first place is the source itself. If it does not have level control you must reduce APL1's gain.
You can do that in Workshop by setting "EQ zero" to some negative number of dB.
You can do that by use of C1 software same time as you are using its parametric eq.

We can "turn" all the curve of eq to "cuts" by bringing up zero of curve (if look to curve as eq curve)
That depends only of overall gain and can be adjusted by two mentioned methods.

All 3 outputs of APL1 - analog, digital coaxial SPDIF and digital optical TOSLINK,
are working all the time in parallel.
You can use any of them in any time.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Hi Friends,
> 
> It is known issue with Full Scale digital signal - no headroom for any kind of processing.
> You must create a headroom by reducing signal level.
> The first place is the source itself. If it does not have level control you must reduce APL1's gain.
> You can do that in Workshop by setting "EQ zero" to some negative number of dB.
> 
> 
> ....



So IF the stock source supplies a full scale digital output and it is run to the input of the APL1, are you saying the APL will not output sound unless the gain structure is adjusted (lowered) according to one of the methods above? Does the APL have a signal peak/clip that mutes the output?
I don't recall if the car's digital output had variable volume but I doubt it. I'll have to follow up and check this out with the signal gain reduced in the EQ Zero setting.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Steve, I believe Raimonds is addressing the clipping folks are having running a digital input. I remember from the get-go him stating all outputs were always on, so I'm not sure where the no output problems are coming from with the digital outs. The last few posts are also the first I've heard of an output "jumper" changing the digital out. I use the optical digital out, but with analog in, and mine was simply "plug and play".


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was about to say like John that there’s a jumper for the digital out but I’m confused now with Raimonds’ answer. But I remember a jumper thing, so was it for the inputs?


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

To be fair, I've only tried the digital out on one unit (it didn't work). Digital out on optical had a light but no audio, regardless of whether I used an analog or digital input to the APL. When using an analog in and out though it worked fine. Could be an isolated issue with that particular device...


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> It has digital in/out (both spdif and toslink) & analog in/out.
> 
> And if I quote Raymond here:
> "All outputs are working simultaneously all the time. You may use any of them.
> But inputs - if digital signal is fed to digital input, the unit is switching from analog input to digital. If no digital signal - analog input is active.
> The jumper switch is for selection between coaxial SPDIF and optical TOSLINK digital inputs."


Found it!


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> I was about to say like John that there’s a jumper for the digital out but I’m confused now with Raimonds’ answer. But I remember a jumper thing, so was it for the inputs?


Yep, I was wrong. It's for the digital inputs, and all the outputs are always running.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Does APL Workshop generate filters that may be used in Viper4Android app or ConvolverVST plugin?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> To be fair, I've only tried the digital out on one unit (it didn't work). Digital out on optical had a light but no audio, regardless of whether I used an analog or digital input to the APL. When using an analog in and out though it worked fine. Could be an isolated issue with that particular device...


I have been using mine for many months or almost a year since I got it on optical out. So it definitely should work.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I just redid my system and am again on the journey to get the house curve that I like and also to tame some issues.

I have been using Clay's curve, JBL, MP1 and ES1 and a modified version of MP1 which does not roll off that much at the top end. 

Everyone still has some issue or something I would like to tweak to sound better. However I think I still like Clay's or my tweaked MP1 with less rolled off highs best. MP1 and JBL curve works very well though if you are listening at a very high volume.

I am however having a issue with male voices being rather Chesty or Nasal. A more accurate description would be some male voices seems to be coming out of a horn. Its also strangely in all the house curves that I m testing. Some has the cut at 1-3Khz of around 3-5db. That does not seem to help much. Anyone have any suggestions? My measurements?


----------



## Mic10is

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I just redid my system and am again on the journey to get the house curve that I like and also to tame some issues.
> 
> I have been using Clay's curve, JBL, MP1 and ES1 and a modified version of MP1 which does not roll off that much at the top end.
> 
> Everyone still has some issue or something I would like to tweak to sound better. However I think I still like Clay's or my tweaked MP1 with less rolled off highs best. MP1 and JBL curve works very well though if you are listening at a very high volume.
> 
> I am however having a issue with male voices being rather Chesty or Nasal. A more accurate description would be some male voices seems to be coming out of a horn. Its also strangely in all the house curves that I m testing. Some has the cut at 1-3Khz of around 3-5db. That does not seem to help much. Anyone have any suggestions? My measurements?


I tried to use a modified jbl curve but it has some really buzzard results. Bc the jbl curve has 20hz above 20hz by 9db then flat out to 20hz

The result was I had to turn sub amp gain down to minimum then cut sub output on dsp to a full -30db. And still had way too much bass

The next issue was it boosted 800hz like crazy yet cut 630hz significantly . So in dsp I has to cut 630 more than 15db and boost cut 800 6db

The nasally sound is in the 630 to 800 region


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I just redid my system and am again on the journey to get the house curve that I like and also to tame some issues.
> 
> I have been using Clay's curve, JBL, MP1 and ES1 and a modified version of MP1 which does not roll off that much at the top end.
> 
> Everyone still has some issue or something I would like to tweak to sound better. However I think I still like Clay's or my tweaked MP1 with less rolled off highs best. MP1 and JBL curve works very well though if you are listening at a very high volume.
> 
> I am however having a issue with male voices being rather Chesty or Nasal. A more accurate description would be some male voices seems to be coming out of a horn. Its also strangely in all the house curves that I m testing. Some has the cut at 1-3Khz of around 3-5db. That does not seem to help much. Anyone have any suggestions? My measurements?



Have you checked the calibration file for your mic? Had some similar problems with mine. It was terrible in a mid-range. So, yes. It could be wrong measurements.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

MP1 has a tendency for this kind of sound (nasal) for some records. I will call it a "dark sound". From my teenage past I do remember my permanent intentions to increase lows and highs. MP1 works in an opposite way. One has to be accustomed to its sound. What you could expect from it - decreased ratio between dry and wet components of a signal, increasing by this the reverb part of it and making room acoustics more evident. If you need this (which I think is quite important in a limited car environment and close placement of the loudspeakers), then mp1 is your correct choice. Efficiency of this effect will depend of the recording quality, mastering, etc. Some studios are simply legendary now, as for example Van Gelder Studio. So try to find good music records and listen to mp1 with a focus on this issue.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> Does APL Workshop generate filters that may be used in Viper4Android app or ConvolverVST plugin?


Answer is no. You will need irs-files for this purpose. Rajmond might help you converting your measurement results into an impulse response, which is applicable for Viper4A.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> MP1 has a tendency for this kind of sound (nasal) for some records. I will call it a "dark sound". From my teenage past I do remember my permanent intentions to increase lows and highs. MP1 works in an opposite way. One has to be accustomed to its sound. What you could expect from it - decreased ratio between dry and wet components of a signal, increasing by this the reverb part of it and making room acoustics more evident. If you need this (which I think is quite important in a limited car environment and close placement of the loudspeakers), then mp1 is your correct choice. Efficiency of this effect will depend of the recording quality, mastering, etc. Some studios are simply legendary now, as for example Van Gelder Studio. So try to find good music records and listen to mp1 with a focus on this issue.


Interesting.
oliverlim, it might also come from the loudness effect. Mp1 tuned at high level but listened at lower level level could give this effect, really increasing the 1khz area.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

When you tune by ear, the volume level plays some role due to the loudness contour. But for the mic is not an important issue. The only requirement during the measurement is to keep diff between signal level and noise floor above 20-25dB.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Sure, should have said "modified" for high levels instead.
It's just based on oliverlim comments where he boosted the highs roll off (that I personally don't see on mp1), something probably done for listening at lower level. And lower levels would call for a low end boost as well or it might sound funky (honky?).
This is highly personal and so setup/car dependent, but stock mp1 is still my go-to for 85db, with or without the 3.5khz dip filled.
I didin't like it for 95+ neither for 75-, needed some tweaks.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

this is very interesting 


It’s about acoustics and big objects 


https://youtu.be/tNHU5KOI9lQ


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

This youtube link ...

Isn't it about stars and planets?


----------



## BrainMach1

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> This youtube link ...
> 
> Isn't it about stars and planets?


I think those qualify as big objects. 

Sent from my SM-G955U using Tapatalk


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> this is very interesting
> 
> 
> It’s about acoustics and big objects
> 
> 
> https://youtu.be/tNHU5KOI9lQ


like the end part! I know it';s off topic but I always found this kind of sound-wave visualization fascinating, ex: https://www.youtube.com/watch?v=wvJAgrUBF4w


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I recently had some chance to seat in my car passenger seat. I think I now know why my wife likes to turn down the volume or switch it off. The sound from the passenger seat feels like it coming just from the tweeter and about a few feet behind it. The tonality is ok but the single point sound is just plain weird. 

So I am now trying to find a tune with compromise so that both driver and passenger will get at least some form of stereo with the center closer to the middle of the car. What should I do?

1. I am now trying to have TA all set at zero. 

2. I am also trying to increase delay very slightly for my underseat woofer which is the "furthest" speaker. 

Any other things to try? It seems that APL does not do anything to widen the sweetspot. I see from Dirac that they seem to have figured out a way to use out of phase FIR EQ to have the passenger and driver be able to have pretty good stereo effect. They write about it here https://www.dirac.com/dirac-virtual-center/

Can APL do something like this? That would be so cool!


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

To follow up on my test on setting Delays to be the middle of the passenger and driver seat.

It makes the Left and Right spilt better. However vocals still seem to come up somewhere directly in front of you or between you and the tweeter position. Still pretty well to the side. At least the stage seems alot better as in there is now a better left and right stage.

So is there a better way to tune a car for 2 seats? I cant imagine that this would be a acceptable solution. I did recall when I did not have a tweeter when the car was stock, that the vocal came more in the middle then at the side. Maybe dropping the frequencies above 3-5K more helps with this?


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Sure, should have said "modified" for high levels instead.
> It's just based on oliverlim comments where he boosted the highs roll off (that I personally don't see on mp1), something probably done for listening at lower level. And lower levels would call for a low end boost as well or it might sound funky (honky?).
> This is highly personal and so setup/car dependent, but stock mp1 is still my go-to for 85db, with or without the 3.5khz dip filled.
> I didin't like it for 95+ neither for 75-, needed some tweaks.


I think u hit it on the nail. There are some volume that mp1 sounds fantastic in my car. Its the as loud as I would car to listen range. But I do not listen at that range all the time. It would seem that at that level, MP1 is fine as the "dark sounding" sound reduces the harshness that can come into play at loud volumes.

At the lower volumes, esp one where you can still talk comfortably, I would say that in my car, the highs and mids dominate the sound. Bass is almost none existence even with the hourse curve on mp1. Probably need a modified mp1 with more bass. Maybe something like 9db boost like in JBL curve.


----------



## claydo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

More bass than mp1? Wow, you like your bass don't ya?


The sub bass is cool in mp1....but for my system the midbass is a bit too much....


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



claydo said:


> More bass than mp1? Wow, you like your bass don't ya?


Haa! Mp1 used to be very good for my system when I was using 8" as my underseat woofers. But I have since moved to a 6.5" and without subs, my guess is that APL1 does not boost more then 6db and my frequency below 50hz drops like a rock now. 

Anyway, I am also trying to compensate for the road noise which according to my phones RTA, is mainly between 100-200hz. So its probably this area that I need a boost for esp at low vol. So I am not ruling out that this is the cause for what I can only describe as lean mids at low volume.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I personally do not like the idea of boosting at 100-200Hz. First of all, mp1 is well designed and balanced. On the second, unnatural boost is not a reliable tool to compensate the road noise. Our brains can easily separate sounds coming from different sources. That is why we are able to listen to a conversation under rather loud environment (so called "party" effect). I agree that at the low end range the mp1 is "rich" with sound level and further boost could destroy the whole idea of it.

Have you tried to combine mp1 and equal level contour (despite that the last one was composed based on the measurements with earphones)? You could try to make your own house curve corresponding to different izofons. Let say 90, 70 and 50. Clear izofon sounds relatively bright, with a lot of details, but not alive (at least for me). Try to compile your own curve which meets your demands. I would just disagree that mp1 lacks sound level at the low end. It might be problems with the setup, phazing, etc. One might try to check how accurate you fit the selected house curve. For this purpose you need to remeasure your system with the apl1 on.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> I personally do not like the idea of boosting at 100-200Hz. First of all, mp1 is well designed and balanced. On the second, unnatural boost is not a reliable tool to compensate the road noise. Our brains can easily separate sounds coming from different sources. That is why we are able to listen to a conversation under rather loud environment (so called "party" effect). I agree that at the low end range the mp1 is "rich" with sound level and further boost could destroy the whole idea of it.
> 
> Have you tried to combine mp1 and equal level contour (despite that the last one was composed based on the measurements with earphones)? You could try to make your own house curve corresponding to different izofons. Let say 90, 70 and 50. Clear izofon sounds relatively bright, with a lot of details, but not alive (at least for me). Try to compile your own curve which meets your demands. I would just disagree that mp1 lacks sound level at the low end. It might be problems with the setup, phazing, etc. One might try to check how accurate you fit the selected house curve. For this purpose you need to remeasure your system with the apl1 on.


Thanks for your thoughts on this. I will try to remeasure my system on TDA and workshop with the apl1 EQ on and see if it is actually working well. I am still playing around with TDA to try to get my crossover/delays improved on my new setup. So it could be i am still having some issues with my setup.


----------



## cycfari

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> I recently had some chance to seat in my car passenger seat. I think I now know why my wife likes to turn down the volume or switch it off. The sound from the passenger seat feels like it coming just from the tweeter and about a few feet behind it. The tonality is ok but the single point sound is just plain weird.
> 
> So I am now trying to find a tune with compromise so that both driver and passenger will get at least some form of stereo with the center closer to the middle of the car. What should I do?
> 
> 1. I am now trying to have TA all set at zero.
> 
> 2. I am also trying to increase delay very slightly for my underseat woofer which is the "furthest" speaker.
> 
> Any other things to try? It seems that APL does not do anything to widen the sweetspot. I see from Dirac that they seem to have figured out a way to use out of phase FIR EQ to have the passenger and driver be able to have pretty good stereo effect. They write about it here https://www.dirac.com/dirac-virtual-center/
> 
> Can APL do something like this? That would be so cool!


I used a center speakers setup with MS-8 in my previous car for 2 seat listening. MP1 bass is heavy. I am now just running APL1 to MS8, 3 way active + small active sub.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> Thanks for your thoughts on this. I will try to remeasure my system on TDA and workshop with the apl1 EQ on and see if it is actually working well. I am still playing around with TDA to try to get my crossover/delays improved on my new setup. So it could be i am still having some issues with my setup.


Safe bet, it’s too easy to spend time on a target even if we know we have other issues uncovered.

About the loudness compensation, I tried this some time ago when I first got my horns and used to listen loud:









3 settings basically:
- for 70/75db > boost low and highs
- for 85/90db untouched
- for 100db cut low and highs

The lowest one was useful, brought up some depth and details while keeping it confortable.
And the highest one didn't really work as intended. I realized that the road noise was naturally masked by the loudness effect at high level (high level means usually high speed for me).
So the compensation on the highs was good, but the low end should have been let untouched.
Well anyway I drop the idea as I just don't bother with settings for that now, and just listen to more reasonable levels.
But I would appreciate if someone builds this feature in a box, or a plugin.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Thanks for the detailed explanation. Actually Audison bit one/bit one hd has a feature called dynamic eq. It allows you to tune 2 different eq curve at Teo different vol levels. So not the three u are looking at but two would also fit what u are trying to achieve with the loudness curve. 





Elgrosso said:


> Safe bet, it’s too easy to spend time on a target even if we know we have other issues uncovered.
> 
> About the loudness compensation, I tried this some time ago when I first got my horns and used to listen loud:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 3 settings basically:
> - for 70/75db > boost low and highs
> - for 85/90db untouched
> - for 100db cut low and highs
> 
> The lowest one was useful, brought up some depth and details while keeping it confortable.
> And the highest one didn't really work as intended. I realized that the road noise was naturally masked by the loudness effect at high level (high level means usually high speed for me).
> So the compensation on the highs was good, but the low end should have been let untouched.
> Well anyway I drop the idea as I just don't bother with settings for that now, and just listen to more reasonable levels.
> But I would appreciate if someone builds this feature in a box, or a plugin.


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



cycfari said:


> I used a center speakers setup with MS-8 in my previous car for 2 seat listening. MP1 bass is heavy. I am now just running APL1 to MS8, 3 way active + small active sub.


Interesting. What does ms8 addition do? I understand it makes fir eq based on a number of location so that it sounds good in those locations?


----------



## cycfari

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oliverlim said:


> Interesting. What does ms8 addition do? I understand it makes fir eq based on a number of location so that it sounds good in those locations?


MS-8 auto-tune the time alignment for different seats. Also if you have a center channel, the center stage will be perfect with added advantage of L7 processing.

However there is not much self tuning options other then EQ & Gain.Correct crossovers selection and amplifier gains still needs to be dialled in before the autotune,

From my personal experience, MS8 is an easy setup for novice but it wont give u the perfect sound.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Dreams come true


Raimonds said:


> Right now, the most compact version is stack of 4 PCBs 75 mm in high.
> The all in one board 10 channel unit is a dream.
> I am thinking about some kind of "kickstarter" project.
> But it is too much business management for an engineer to do that.
> 
> The target or parametric eq can be used for each particular unit/driver/way
> and for all system as master.
> You can use ordinary parametric EQ interface and/or input as a curve in form of txt file.


10 channel unit with master EQ on input (12 FIR cores) is ready to serve demanding customers : )


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Dreams come true
> 
> 
> 10 channel unit with master EQ on input (12 FIR cores) is ready to serve demanding customers : )


The board looks pretty small. Please do one for car installation


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> 10 channel unit with master EQ on input (12 FIR cores) is ready to serve demanding customers : )



Great news, Raimonds! Will keep it in mind for my next install.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Has anybody tried this Amarra player with in-built convolution feature? 

Amarra 4 Luxe 

It has a native support for DSD64/128 files and option for impulse response correction "on the go". For IOS 10x and Win 8 (and higher) users.

It seams that this player allows to use ordinary units (f.ex. iphone/ipod/ipad) as a source in the car with the stock install for better sounding. Using APL Workshop, one will be able to create (with the help of Raimonds) own IRS-files for correction of the sound in a car. 

Sounds impressive, am I wrong?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Dreams come true
> 
> 
> 10 channel unit with master EQ on input (12 FIR cores) is ready to serve demanding customers : )


Well golly, looks I need some of those in my Home Theater rack!  

Does it use the same software as in this post?: http://www.diymobileaudio.com/forum/4913258-post836.html

2 channels in and 10 out?

What's the price tag on that? 

Is the white switch on the front a second power switch, or a bypass switch?

Are those digital in/out RCA plugs inside the unit functional?


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



crackinhedz said:


> I have to say, I love the APL.
> 
> But, my experience with the VST has not been very ideal. First, foobar2000 works perfect with the VST, but I hate foobar2000 as my media player...not very carpc friendly, small text etc.


Not quite correct. There are some versions of foobar2000, which are designed to be used in a car environment.

There is just one example. 

https://www.youtube.com/watch?v=iodM_cT2uFM

As soon it is a Windows version (carPC) - you are able to use the APL VST plugin fot it.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Dreams come true
> 
> 
> 10 channel unit with master EQ on input (12 FIR cores) is ready to serve demanding customers : )


OK What does this mean... 12 FIR cores, and 10 channels?
Is the FIR based EQ done on the left and right independently, and then the remaining 5 channels per side are bandpass crossover outputs?

If the EQ is done on the input then what happens in the passband? It seems like ripples would be different on the low-side and high-side speakers, so the phase correction would need to be different on each speaker??

And it sort of seems like it is similar to a DDRC-88A, but with access to the FIR filters - or am I wrong?

Also, I could not exactly see this on the APL home page.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Check here: https://www.facebook.com/aplaudio


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Holmz said:


> OK What does this mean... 12 FIR cores, and 10 channels?
> Is the FIR based EQ done on the left and right independently, and then the remaining 5 channels per side are bandpass crossover outputs?
> 
> If the EQ is done on the input then what happens in the passband? It seems like ripples would be different on the low-side and high-side speakers, so the phase correction would need to be different on each speaker??
> 
> And it sort of seems like it is similar to a DDRC-88A, but with access to the FIR filters - or am I wrong?
> 
> Also, I could not exactly see this on the APL home page.


Thank you for questions!

You should compare results of mentioned “similar” solution in fields of car audio competitions and pro audio. And how much they trust themselves in terms of investment to develop own hardware.
.
You should also check how far in “moon shining” they are from original work
https://www.google.com/patents/US8121302
published at May 18, 2005

Real competitor products are Dolby Lake and Fouraudio HD2

Thanks to Elgrosso for pointing to preliminary press release on APL’s facebook

FIR based EQ should be done in each of bands.
Then final FIR based EQ should be used on overall system (master EQ on input) to fine tune small residual crossover tuning errors and to use any targets.

10 channels means 10 analog output channels.
12 FIR cores means 12 independent FIR filters with 4096 taps each (in first release, later will be more, especially for 96 and 192kHz versions)
Any of FIRs can be any kind of filter and are not tighten to some bandpass or else.
As example, the unit can be configured as 12 channels EQ

The detailed correction of each speaker makes crossover “ideal” with complementary ripples, amplitude and phase responses. This actually is making all the value for use FIRs on each band.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Thank you for questions!
> 
> You should compare results of mentioned “similar” solution in fields of car audio competitions and pro audio. And how much they trust themselves in terms of investment to develop own hardware.
> .
> You should also check how far in “moon shining” they are from original work
> https://www.google.com/patents/US8121302
> published at May 18, 2005
> 
> Real competitor products are Dolby Lake and Fouraudio HD2
> 
> Thanks to Elgrosso for pointing to preliminary press release on APL’s facebook
> 
> FIR based EQ should be done in each of bands.
> Then final FIR based EQ should be used on overall system (master EQ on input) to fine tune small residual crossover tuning errors and to use any targets.
> 
> 10 channels means 10 analog output channels.
> 12 FIR cores means 12 independent FIR filters with 4096 taps each (in first release, later will be more, especially for 96 and 192kHz versions)
> Any of FIRs can be any kind of filter and are not tighten to some bandpass or else.
> As example, the unit can be configured as 12 channels EQ
> 
> The detailed correction of each speaker makes crossover “ideal” with complementary ripples, amplitude and phase responses. This actually is making all the value for use FIRs on each band.


Ok
1) What happens on Subwoofer channels?
I think that ideally one would filter-decimate the sample rate down... but I suspect that all the cores run at full sample rate.
So should I be concerned with filter resolution in the subwoofer band?

2) would I still need something else to do time alignment?
Or is time delay conceptually the same as rotating the taps to the right or left?

3) What is this unit called?

4) What is the Euro price?

5) is it available now? Or when it is to be released?

6) how does one start? As in what software tools should I get for use in OSX?
Or do I need to run windows in a VM?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I’m seriously considering it!
Any plan to port your soft on mac?


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Holmz said:


> Ok
> 1) What happens on Subwoofer channels?
> I think that ideally one would filter-decimate the sample rate down... but I suspect that all the cores run at full sample rate.
> So should I be concerned with filter resolution in the subwoofer band?


You are on the button! I am considering that for 96/192 kHz.
The 4096 taps for 48kHz (85ms ir) is pretty much ok 



> 2) would I still need something else to do time alignment?
> Or is time delay conceptually the same as rotating the taps to the right or left?


C5 software is managing this in exactly mentioned way.



> 3) What is this unit called?


APL1012a


> 4) What is the Euro price?


negotiated from deal to deal



> 5) is it available now? Or when it is to be released?


Yes, please make your order!



> 6) how does one start? As in what software tools should I get for use in OSX?
> Or do I need to run windows in a VM?





Elgrosso said:


> I’m seriously considering it!
> Any plan to port your soft on mac?


1) You need Workshop or TDA EQ for basic measurement.
2) TDA - for crossover tuning, time alignment
3) C5 - for all the management.

You will need Windows on VM for Workshop to run on mac.
TDA series programs and C5 can be ported to mac with
pretty much not so big effort. 
But it depends on your (customers) support to this project.
It was considered as some kind of "kikstarter" project at August last year.
Now, it is ready for orders without that.
But anyway, your early orders will help a lot.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

OK...

Q7) So would subwoofer management be a software implementation _- with some filter-decimate brickwall convolution 'pre-stage' that can happen in the future?_

Q8) Are the DSPs cores fixed point or floating point?
_I have an analogue radio/CD that I was set on using... But then I got a new (used) unit that has a digital out?
The amps are old school jobs that are on RCAs, so I am thinking about whether I need to worry about low level signals and whether at quieter volumes I will be running out of bit depth... (The higher sample rates should help) The new radio/CD does 24bit CDs, but I have no idea what happens with the aux inputs from say an iPad, or an iPad into a GPS-aux input with a bluetooth phone, and then all the mess back into one of the radio's 2 aux inputs. _


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> 1) You need Workshop or TDA EQ for basic measurement.
> 2) TDA - for crossover tuning, time alignment
> 3) C5 - for all the management.
> 
> You will need Windows on VM for Workshop to run on mac.
> TDA series programs and C5 can be ported to mac with
> pretty much not so big effort.
> But it depends on your (customers) support to this project.
> It was considered as some kind of "kikstarter" project at August last year.
> Now, it is ready for orders without that.
> But anyway, your early orders will help a lot.


Very interesting!
C5/TDA running on mac, that’s the trigger I needed.
Workshop I'm ok to play it on VM as it's not so often.
Ok then email now, thank you Raimonds.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Holmz said:


> OK...
> 
> Q7) So would subwoofer management be a software implementation


 Anyway, it must be hardware.
The good idea is to use as short FIRs as possible - to have as small "time smearing" as possible. 4096 taps can be sufficient for sub processing with that in mind.




> Q8) Are the DSPs cores fixed point or floating point?


They are no floating point as we know that from computer science.
They are floating point in terms that the point is floating to keep max accuracy for all computation - no quantization used till output.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> Safe bet, it’s too easy to spend time on a target even if we know we have other issues uncovered.
> 
> About the loudness compensation, I tried this some time ago when I first got my horns and used to listen loud:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 3 settings basically:
> - for 70/75db > boost low and highs
> - for 85/90db untouched
> - for 100db cut low and highs
> 
> The lowest one was useful, brought up some depth and details while keeping it confortable.
> And the highest one didn't really work as intended. I realized that the road noise was naturally masked by the loudness effect at high level (high level means usually high speed for me).
> So the compensation on the highs was good, but the low end should have been let untouched.
> Well anyway I drop the idea as I just don't bother with settings for that now, and just listen to more reasonable levels.
> But I would appreciate if someone builds this feature in a box, or a plugin.


Ok ^that^ is pretty slick!




Raimonds said:


> Anyway, it must be hardware.
> The good idea is to use as short FIRs as possible - to have as small "time smearing" as possible. 4096 taps can be sufficient for sub processing with that in mind.
> ...


I saw on the C5 photo that the sample rate was selectable for each channel. If there was a ADC running at 4K, then one could probably do the subwoofer with 256 taps? Or do all the channels need to be the same sample rate? (I understand aliasing and Nyquist theorem.)



Raimonds said:


> ...
> They are no floating point as we know that from computer science.
> They are floating point in terms that the point is floating to keep max accuracy for all computation - no quantization used till output.


Ok - I did not do computer science at uni, however I seem to be doing it most of the time. I recall Estonia having the best internet in the world (a few years ago), so I assume Latvia is similarly advanced in technology? - based just on proximity alone.


----------



## Hanatsu

*Comprehensive Review: &quot; APL1 &quot; - Advanced DSP / EQ / Phase Correction Unit*

I don’t think the sampling frequency can be arbitrary set due to hardware but I could be wrong...


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi,
Take a look on car version of APL1012!


----------



## Bnlcmbcar

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How soon can we expect the car version of the APL1012 to be available for purchase? Any pricing yet?

I’m going back and forth between going with APL-1S unit or the Dirac DDRC 22D or DDRC 88a. This car version APL1012 seems to be the most ideal!!


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Nice Raimonds!

Is there a connection for the ribbon cable of the preset switch on the outside of the enclosure?


-Steve


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I also noticed that there is no optical input?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



captainobvious said:


> Nice Raimonds!
> 
> Is there a connection for the ribbon cable of the preset switch on the outside of the enclosure?
> 
> 
> -Steve


I wouldn't be surprised if it's the same as the APL1, where the ribbon cable is sandwiched between the lid and the rest of the case. 

I do need to get more info from Raimonds about how to make a simple 2-tune switch from the ribbon cable.


----------



## Weightless

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> ...I do need to get more info from Raimonds about how to make a simple 2-tune switch from the ribbon cable...


I'll get you started. I was going to do something similar, because when will I ever need 16 presets? 

He sent me the pinout for the rotary knob. I haven't had a chance to take it past that, though. 

His response about the pinout:

"Yes, you can use any multi-conductor cable and no need for shield.

Actually working wires are 5.

*

Here is cable's pinout

*

1 signal 1

2 ground

3 signal 2

4 ground

5 not in use

6 ground

7 signal 3

8 ground

9 signal 4

10 ground





Sent from my SM-N920P using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Bnlcmbcar said:


> How soon can we expect the car version of the APL1012 to be available for purchase? Any pricing yet?
> 
> I’m going back and forth between going with APL-1S unit or the Dirac DDRC 22D or DDRC 88a. This car version APL1012 seems to be the most ideal!!


It is available! Please make your offer : )



captainobvious said:


> Nice Raimonds!
> 
> Is there a connection for the ribbon cable of the preset switch on the outside of the enclosure?
> 
> -Steve


YES! You can see two mini XLRs on back panel. The 5 pin one is for preset switch. The 3 pin one is for remote volume control.



oliverlim said:


> I also noticed that there is no optical input?


The optical in is available on main PCB temporarily.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

APL1012 - Great device! Especially for those who will make 3-way active install. As I understood, appart from the preset switch, there is a separate volume control for the whole system. Or for subwoofer channel only? 

Looking forward to install it in a new car.

Recently I have read an article by Chris Huff "Seven keys to making voices sound like you want them to sound" published in Church Sound 3/2018 and it reminded me some discussions about the target curve called mp1 from Rajmonds Scuruls.

Recommendations mentioned in this article are quite simple, but after their implementation, you will be surprised of how the shape of the final frequency response curve looks like. it is almost similar to the above mentioned target curve mp1. And it makes sense.


----------



## Durgesh

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was planning to upgrade my processor and have finally decided to buy either APL1 or 1012. Already in conversation with Raimonds on the purchase.

I am in two minds...whether I should buy 3 units of Apl-1 or 1xAPL1012. 

3xApl1 should give me more freedom of use. My existing processor is alpine pxa-h800 which can do active 3 way front+ sub and also multichannel 5.1 surround (2way front/centre/rear/sub)

Having three units of Apl-1 will give me 06 channels of analogue input and 6 on output. They can used in multichanel surround system also. 3xApl can be placed between pxa-h800 and the amps. 

Similarly I can use them in my HT also for testing the differnce in sq. At least front/center/sub and a pair of surround out from my Av-processor can be processed for eq with Apl-1. 

My current car setup is 3way active front + sub setup.
1xApl1 can be used for mid range + tweeter (with passive crossover)
1xApl1 can be used for midbass 
1×Apl1 for sub (or rears if I add later)
All 3 units can be placed between my existing dsp and amps. Crossover and Ta can be managed from the dsp.

1xAPL-1012 will give more control in a 3way active front + sub+rears. 

Considing the flexibbility 3xapl1 will provide, will Apl-1012 provide any major noticeable benefits in sq?

Pls help me in deciding.

Thanks







Sent from my SM-G950F using Tapatalk


----------



## Miguel mac

Hi

Is someone using the VST?


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Miguel mac said:


> Hi
> 
> Is someone using the VST?


I do - with foobar2000 in Windows and with Viper4a in Android OS. What is the question? Do you have some issues with it?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I was just scanning this thread again because I'll be doing some more tuning soon. In the very first post there is a screen shot of Coneq PE1, and in that screenshot is the web address Coneq Out of curiosity I went there. I poked around on both branches of that site and was a surprised at how similar the software seemed to APL Workshop. Heck, the software for this hardware is even called Coneq Workshop!

As a Mac user, I was excited to see the Mac software, so I downloaded it. Unfortunately, I don't have a license key, and finding a way to get one is... Difficult. Hmmm.

So I continued to poke around on the site and found this: http://www.coneqpro.com/en/downloads/coneqtechnologyshort.pdf
Read the History paragraph.

So now I have a couple questions for Raimonds: 

1: Is Coneq Workshop compatible with the APL1? 
2: If so, how do I get a license?
3: I got a warning about the software being old when I ran it on MacOS 10.13.4, have you ended development of it?


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Curious to get the end of this business story too, they have cool hardware and apparently use the same algorithm, but last time I tried when I had my apl was with no luck too.
But even if it’s outdated and feature limited I’d be interested.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Both companies are built on Raimonds tech, I wonder why the split?

Not having to fire up Windows would be awfully nice, especially now that JL has MacOS software for TüN.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How do you like TüN so far?
I only quickly played with it, and if it looked nice I was a bit perplex.
But it must the mini plugins habits, I can’t see myself dropping the biquads and rew integration though.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> How do you like TüN so far?
> I only quickly played with it, and if it looked nice I was a bit perplex.
> But it must the mini plugins habits, I can’t see myself dropping the biquads and rew integration though.


At the moment, I'm not too happy with it, see here: http://www.diymobileaudio.com/forum/5436858-post231.html


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I was just scanning this thread again because I'll be doing some more tuning soon. In the very first post there is a screen shot of Coneq PE1, and in that screenshot is the web address Coneq Out of curiosity I went there. I poked around on both branches of that site and was a surprised at how similar the software seemed to APL Workshop. Heck, the software for this hardware is even called Coneq Workshop!
> 
> As a Mac user, I was excited to see the Mac software, so I downloaded it. Unfortunately, I don't have a license key, and finding a way to get one is... Difficult. Hmmm.
> 
> So I continued to poke around on the site and found this: http://www.coneqpro.com/en/downloads/coneqtechnologyshort.pdf
> Read the History paragraph.
> 
> So now I have a couple questions for Raimonds:
> 
> 1: Is Coneq Workshop compatible with the APL1?
> 2: If so, how do I get a license?
> 3: I got a warning about the software being old when I ran it on MacOS 10.13.4, have you ended development of it?


Hi,
Everything mentioned is at least 10 years old and stolen in that time.
Therefore, no any kind of support ...
Real Sound Lab is dead for long years already. Thanks to enormous level of crime ...

Regarding working environment.
From time to time I am suggesting to add to your measurement mic and sound card a piece of hardware for about $100 with 4 core 1.8GHz processor, 4G RAM, HDMI, Ethernet, Wifi, 2 USB and W10.
It is taking 2Wats from 5V power supply ...
Its size is 12x12x2 cm
It is called mini PC


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is there a happy owner of the APL1012 on this forum? Wondering to hear a little review and practical experience with it. Pros and cons if any.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> Is there a happy owner of the APL1012 on this forum? Wondering to hear a little review and practical experience with it. Pros and cons if any.


If you can wait a month or 3 then I will supply a review for you.


As far as the practical experience...

I have a new battery for the Mrs' MacBook-P, and I chucked in a new SSD into her windows work computer, so I have been going slow on the S/W front.
(Job 1 is to get S/W installed under the parallels VM)

But these things are the same for most tuning S/W that are windows based.


----------



## Elgrosso

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> Is there a happy owner of the APL1012 on this forum? Wondering to hear a little review and practical experience with it. Pros and cons if any.


We should get feedback soon >
http://www.diymobileaudio.com/forum...ry/144986-vw-passat-b5-2000-sql-build-17.html


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Elgrosso said:


> We should get feedback soon >
> 
> http://www.diymobileaudio.com/forum...ry/144986-vw-passat-b5-2000-sql-build-17.html



Yep, been a little busy. Review is 90% done, should be posted in coming days. It’s a very interesting unit...


----------



## thehatedguy

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Waiting on one to get here...I hope I can figure it out and love it.


----------



## Hanatsu

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

*Here's a review of the new 1012 unit if you missed it:*

APL 1012 DSP


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Spartak802 said:


> Is there a happy owner of the APL1012 on this forum? Wondering to hear a little review and practical experience with it. Pros and cons if any.


I have a unit but have been using it as a desktop 2.2 system. It was meant to replace my apl1 and audison bit one HD. But I ran into space issue due to the size of the unit.

I also just completed the install of my sub in my trunk. Hopefully i can look into integrating the unit into my car soon.

In my desktop, just using it for the crossovers without measurement. It has sounded great. Probably the crossovers. Just sounds clean compared to LR24 crossovers. Just got my replacement mic so hopefully can run it with some measurements to see how it does in my desktop.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Dear Friends,
I must announce that the update of Windows 10 called "2018 April" is not supporting drivers of APL. It is just one Windows version that is known as not supporting.
May be it is because of fact that mentioned update is too much fresh and issue will be fixed.
BR,
Raimonds


----------



## oliverlim

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Dear Friends,
> I must announce that the update of Windows 10 called "2018 April" is not supporting drivers of APL. It is just one Windows version that is known as not supporting.
> May be it is because of fact that mentioned update is too much fresh and issue will be fixed.
> BR,
> Raimonds


Hi Raimonds,

I am happy to report that the latest one June 2018 feature upgrade supports APL drivers again.


----------



## Spartak802

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Great news, thanks.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Since this is the main thread with a huge collection of APL related knowledge, i decided to post my question here.

If one wants to get the best sounding two-seat tune possible, that is, a tune allowing both listeners to enjoy relatively nice FR and image, how would one perform the measurements? Once at drivers seat and then at passenger's?

How one should setup the time alignment? Set in between the headrests of two seats?


----------



## Alextaastrup

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> Since this is the main thread with a huge collection of APL related knowledge, i decided to post my question here.
> 
> If one wants to get the best sounding two-seat tune possible, that is, a tune allowing both listeners to enjoy relatively nice FR and image, how would one perform the measurements? Once at drivers seat and then at passenger's?
> 
> How one should setup the time alignment? Set in between the headrests of two seats?


Using the apl-technology you must use the whole volume of the cabin except 10-15cm from all the surfaces painting some curves with a mic., despite you are measuring for left or right channel.
Time alignment is necessary to obtain a perfect sound imaging.
For two persons it is not achievable. It will always be a compromise.
Try to use the same time delays for a driver and passanger seat.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So, um...

https://www.audiosciencereview.com/...-measurements-of-acoustic-power-apl1-dsp.7278


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Alextaastrup said:


> Using the apl-technology you must use the whole volume of the cabin except 10-15cm from all the surfaces painting some curves with a mic., despite you are measuring for left or right channel.
> Time alignment is necessary to obtain a perfect sound imaging.


I know this is kinda violates the original recommendation, but i personally have achieved the best sounding tune by measuring a cube of about 50x50x50cm around my head position. It gave me a very solid image and very nice FR. And i experimented a lot.

But when tuning for two passengers, using the whole cabin makes more sense. Even tuning with the passenger present is a better idea, i guess.



> For two persons it is not achievable. It will always be a compromise.
> Try to use the same time delays for a driver and passanger seat.


Yes, i agree - it will never sound as good as one seat tune. The question is how to achieve the best sounding compromise.

When you say "same time delays for a driver and passanger seat" - what do you mean? I can set time delays so the sound arrives at the same time at the drivers position or at passenger. Do you mean one should use something in between?


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> I know this is kinda violates the original recommendation, but i personally have achieved the best sounding tune by measuring a cube of about 50x50x50cm around my head position. It gave me a very solid image and very nice FR. And i experimented a lot.
> 
> But when tuning for two passengers, using the whole cabin makes more sense. Even tuning with the passenger present is a better idea, i guess.
> 
> 
> 
> Yes, i agree - it will never sound as good as one seat tune. The question is how to achieve the best sounding compromise.
> ...


I think that the drivers tune, the passengers tune, and the combo tune would use 3 presets.
To a large extent the phase and EQ would be similar between them.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> So, um...
> 
> https://www.audiosciencereview.com/...-measurements-of-acoustic-power-apl1-dsp.7278


Not surprising. Pro audio equipment never has high quality components like home audio does.


Home audio is about making is sound really, really good for 1 person.

Pro audio is about making it not completely terrible for as many people as possible.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Not surprising. Pro audio equipment never has high quality components like home audio does.
> 
> 
> Home audio is about making is sound really, really good for 1 person.
> 
> Pro audio is about making it not completely terrible for as many people as possible.



This could almost be an answer to StabMe,  Either way, the test results don't take away from the wins people have gotten with the APL1 in competitions. Maybe car stuff is even worse than pro stuff? Him and I talked yesterday, I will be sending in the JL TwK D8 I have sitting around...

Also, 

StabMe, you aren't the only one to get better results when measuring around around your head only. The unit was designed for pro audio and adapted for car use. In the pro world you need to make the sound system sound as good as you can for the entire room, not just for one person. Raimonds recommendation to measure the entire listening space reflects this. But in a one seat car, we don't care about the rest of the room, even in a two seat car we don't care about the rest fo the car. So it seems to work best for us to only measure around the area where the people will actually be.

For example, I have one in my living room and only measured the sofa area, it's the only area that matters. That unit will eventually go in my garage, and when it does I'll measure the entire garage, because when I'm working in it I use the whole space.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Well, i use pro audio stuff both in my car and at home. 

It is a car pc with MOTU 828 mk2 firewire audio interface and PA components - Beyma midbasses, Audax Midrange, Eric's HLCDs. Amplifiers are from the car audio world, of course i am not using PA rack amps 

Similar setup at home.

Yeah, measuring around the head works better in my case, no doubt about it. It works better at home, too.


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Hi Friends,
We already hit the 1000 post here!
Thanks to Alexander (Alextaastrup)!




LumbermanSVO said:


> So, um...
> 
> https://www.audiosciencereview.com/...-measurements-of-acoustic-power-apl1-dsp.7278


Mentioned "science" is very far from real science with respective accuracy and approach.
The used codec chip is CS4270 not CS4290 as mentioned.
Published measurements meet the datasheet of CS4270 very well.
SR frequency range of digital input of APL1 is up to 96 kHz (102 kHz absolute max) and not more.
The measurement on 176 kHz is highly incorrect.
Was the unit in bypass when the test of 1 kHz square wave was conducted?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Mentioned "science" is very far from real science with respective accuracy and approach.
> The used codec chip is CS4270 not CS4290 as mentioned.
> Published measurements meet the datasheet of CS4270 very well.
> SR frequency range of digital input of APL1 is up to 96 kHz (102 kHz absolute max) and not more.
> The measurement on 176 kHz is highly incorrect.
> Was the unit in bypass when the test of 1 kHz square wave was conducted?


The unit was in bypass for all the tests.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The picture of the unit showing the meters was not in bypass mode. Bypass mode has purple LEDs, not Blue.


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The picture doesn't show that, but right below he says he tested it in bypass.

Also, when I powered it back up at home I was thrown off by the purple lights, I hadn't actually set one to bypass before.

And last, I loaded it with flat -5db files generated from C1 before sending it. So if he didn't test it in bypass, it shouldn't have done anything weird.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Also, he tested it as a DAC, which I don’t think anyone actually uses it for.

I know mine is going coax digital into my Helix.


Sent from my iPhone using Tapatalk


----------



## Raimonds

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Some clarification,
The square wave was two times clipped in the mentioned test.
Now, the problem to the smart guys - how it is possible?
Or, in another words (prompting : ), what is max undistorted level for the square wave?


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Raimonds said:


> Some clarification,
> The square wave was two times clipped in the mentioned test.
> Now, the problem to the smart guys - how it is possible?
> Or, in another words (prompting : ), what is max undistorted level for the square wave?





Well, level in the tests shows appx 3.5v I assume the input sensitivity needs to be considerably lower. I believe the analog input is only rated for something like 2v...correct?



Either way, it appears to be over driven at the input.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Not surprising. Pro audio equipment never has high quality components like home audio does.
> 
> 
> Home audio is about making is sound really, really good for 1 person.
> 
> Pro audio is about making it not completely terrible for as many people as possible.


That’s a load of crap .   (jk) 
There’s some bad ass pro audio gear . And there’s some ****ty pro audio gear. 
This falls in the line of ****ty pro audio gear and ****ty car audio gear. 
End of story guys


----------



## cycfari

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is the default APL1 digital input toslink or Spdif?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



cycfari said:


> Is the default APL1 digital input toslink or Spdif?


All inputs and outputs are active, so you can use either.

I am using optical in and coax out on mine.


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



oabeieo said:


> That’s a load of crap .   (jk)
> There’s some bad ass pro audio gear . And there’s some ****ty pro audio gear.
> This falls in the line of ****ty pro audio gear and ****ty car audio gear.
> End of story guys


Nothing in the pro audio world compares to the kind of high-end quality you can find on serious home audio gear.

For example, you will never find a pro audio piece with a DAC chipset that even comes close to being equal to an Auralic Vega G2 + LEO Master Clock combo.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> Nothing in the pro audio world compares to the kind of high-end quality you can find on serious home audio gear.
> 
> For example, you will never find a pro audio piece with a DAC chipset that even comes close to being equal to an Auralic Vega G2 + LEO Master Clock combo.


I was playin , yeah I know . I was just being silly. 
But to be fair , there’s some very good pro audio gear as well. 
But I get what your saying. The level of precision down to every detail in some of the home stuff is insane. 

And I was busting everyone’s balls about the apl with that not so good review.
It would silly to think that if that level of testing was done on a minidsp or a helix or anything we use would show some issues as bad or worse.


I would probably cry with embarrassment if I tested the digital noise in my minidsp using a cigarette lighter usb adaptor as a power supply on one device and the other device downstream on the toslink uses a dc isolators and upstream coming from a head unit. I’m sure there’s something ugly going on that I’m completely oblivious to.


----------



## an.vamv

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> I know this is kinda violates the original recommendation, but i personally have achieved the best sounding tune by measuring a cube of about 50x50x50cm around my head position. It gave me a very solid image and very nice FR. And i experimented a lot.




StabMe , do you make all your measurements within this cube area i.e the initial individual driver measurements and the subsequent full range per side measurements too ? 
The 50x50x50 cm cube area extends behind your head too ? How many measurements on average you take within this cube section?

Has anyone else successfully experimented with alternative measurement areas than those suggested by Raimonds??


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



an.vamv said:


> StabMe , do you make all your measurements within this cube area i.e the initial individual driver measurements and the subsequent full range per side measurements too ?
> The 50x50x50 cm cube area extends behind your head too ? How many measurements on average you take within this cube section?
> 
> Has anyone else successfully experimented with alternative measurement areas than those suggested by Raimonds??


A different way to approach the question is by asking what can be done, and what can be done with a FIR based unit?

For *impulse repsonse correction* (e.g. DIRAC), then ideally one builds those filter outside of the vehicle in a chamber.

For *EQ correction* then that requires the speakers to be in the vehicle. And likely more measurement locations are better as null caused by destructive interference are skipped over.

For *TA* that is likely best using the small cube, unless one wants a tune for more than 1 person.

For *Cross overs* it really doesn't matter much as those can be built and deployed without follow up measurements... especially as the FIR allows for zero phase in the cross over region.
In reality the phase and the TA may benefit from measurements to avoid nulls when speakers are not colocated and even more so for a 2-person tune.

For *reflection cancellation* it is certainly possible to measure the response and build the inverse of a comb-filter to remove the reflections, which looks suspiciously similar to something like active noise cancelation.

For *group delay correction* it is also likely best to do that out of the vehicle, but in the vehicle is certainly possible with enough measurements to aid in beating the SNR up.

If one was doing it all by hand with rephase, then it is how I would approach it.
(One at a time)
In reality it can all be done automatically, however I do not know exactly what is all being done.

With the FIR one gets group delay and impulse response correction as well as zero phase cross overs.
Whether ^all that^ is more important than disciplined clocks and better A2Ds & DACs is dependent upon the user.

For sealed boxes and flat speaker response, then there is less in the way of completing need.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

I correct with APL only the full range.
The speakers are already time-aligned using REW and loopback measurements, level matched and i am using linear-phase crossovers. I generated them in Rephase with some minor EQ to correct huge dips of nulls and then, on top of that, i measure the aforementioned cube area with APL. I get about 80-100 measurements per side on APL.

By the way, level matching in REW doesn't may not necessarily work in how APL "sees" those level. Before applying the correction, i may re-do measurements in APL until levels in the power response across all the speakers in a three way look more or less even. 




an.vamv said:


> StabMe , do you make all your measurements within this cube area i.e the initial individual driver measurements and the subsequent full range per side measurements too ?
> The 50x50x50 cm cube area extends behind your head too ? How many measurements on average you take within this cube section?
> 
> Has anyone else successfully experimented with alternative measurement areas than those suggested by Raimonds??


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

How are you getting Rephase filters into the APL1?


Sent from my iPhone using Tapatalk


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



subterFUSE said:


> How are you getting Rephase filters into the APL1?
> Sent from my iPhone using Tapatalk


I am not. I am using CarPC with a multichannel audio interface. Rephase filters are used in Reaper via Pristine Space VST. APL stays behind those in the signal chain.


----------



## oabeieo

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

From what I’ve heard on DIY home guys are doing it 



subterFUSE said:


> How are you getting Rephase filters into the APL1?
> 
> 
> Sent from my iPhone using Tapatalk


You can use rephase filters in apl it’s under LPCM than pick the sample rate and if mono or stereo (probably mono for each channel I assume)


----------



## an.vamv

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



Holmz said:


> A different way to approach the question is by asking what can be done, and what can be done with a FIR based unit?
> 
> For *impulse repsonse correction* (e.g. DIRAC), then ideally one builds those filter outside of the vehicle in a chamber.
> 
> For *EQ correction* then that requires the speakers to be in the vehicle. And likely more measurement locations are better as null caused by destructive interference are skipped over.
> 
> For *TA* that is likely best using the small cube, unless one wants a tune for more than 1 person.
> 
> For *Cross overs* it really doesn't matter much as those can be built and deployed without follow up measurements... especially as the FIR allows for zero phase in the cross over region.
> In reality the phase and the TA may benefit from measurements to avoid nulls when speakers are not colocated and even more so for a 2-person tune.
> 
> For *reflection cancellation* it is certainly possible to measure the response and build the inverse of a comb-filter to remove the reflections, which looks suspiciously similar to something like active noise cancelation.
> 
> For *group delay correction* it is also likely best to do that out of the vehicle, but in the vehicle is certainly possible with enough measurements to aid in beating the SNR up.
> 
> If one was doing it all by hand with rephase, then it is how I would approach it.
> (One at a time)
> In reality it can all be done automatically, however I do not know exactly what is all being done.
> 
> With the FIR one gets group delay and impulse response correction as well as zero phase cross overs.
> Whether ^all that^ is more important than disciplined clocks and better A2Ds & DACs is dependent upon the user.
> 
> For sealed boxes and flat speaker response, then there is less in the way of completing need.



Holmz, in practice how do you approach the issue of measurements with Workshop ??


----------



## an.vamv

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> I correct with APL only the full range.
> The speakers are already time-aligned using REW and loopback measurements, level matched and i am using linear-phase crossovers. I generated them in Rephase with some minor EQ to correct huge dips of nulls and then, on top of that, i measure the aforementioned cube area with APL. I get about 80-100 measurements per side on APL.
> 
> By the way, level matching in REW doesn't may not necessarily work in how APL "sees" those level. Before applying the correction, i may re-do measurements in APL until levels in the power response across all the speakers in a three way look more or less even.



Stabme, when you do the Workshop measurements for level matching of the power responses of all drivers , do you use the area suggested by Raimonds or your cube?
In Workshop what accuracy of level matching you aim at between L/R channel and across the three ways, how many dBs ? I have found it quite difficult to match all six levels of acoustic power frequency response for a 3way system.


----------



## captainobvious

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



an.vamv said:


> Stabme, when you do the Workshop measurements for level matching of the power responses of all drivers , do you use the area suggested by Raimonds or your cube?
> In Workshop what accuracy of level matching you aim at between L/R channel and across the three ways, how many dBs ? I have found it quite difficult to match all six levels of acoustic power frequency response for a 3way system.



Since you are doing measurements of L side and R side, then this shouldn't be an issue. If the sound seems shifted to the left or right of center when complete, then simply adjust one of the following:


1. Balance of source L-R
2. Adjust gain in DSP for L or R side drivers together for more/less output to center up
3. Adjust the filter gain of one side to center up.


----------



## Holmz

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



an.vamv said:


> Holmz, in practice how do you approach the issue of measurements with Workshop ??


My description was more academic, and how one might generically do this in MATLAB or similar.
I thought someone was doing a video?


----------



## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> By the way, level matching in REW doesn't may not necessarily work in how APL "sees" those level. Before applying the correction, i may re-do measurements in APL until levels in the power response across all the speakers in a three way look more or less even.


You can import the DAT files that Workshop creates directly into REW. By doing this, you can do all of your measuring with Workshop so what you see in both apps matches each other.

There are some specific things that REW can't do with the DAT files(like waterfall plots) but it's a great way to compare what you are doing in both apps.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



an.vamv said:


> Stabme, when you do the Workshop measurements for level matching of the power responses of all drivers , do you use the area suggested by Raimonds or your cube?
> In Workshop what accuracy of level matching you aim at between L/R channel and across the three ways, how many dBs ? I have found it quite difficult to match all six levels of acoustic power frequency response for a 3way system.


I level match each speaker separately with REW and pink noise using moving mic technic. Yes, the same area. When speakers are more or less level matched, i measure in Workshop and this time it is a stereo signal with crossovers and level matching applied, not each speaker individually. Pretty basic technique.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> You can import the DAT files that Workshop creates directly into REW. By doing this, you can do all of your measuring with Workshop so what you see in both apps matches each other.
> 
> There are some specific things that REW can't do with the DAT files(like waterfall plots) but it's a great way to compare what you are doing in both apps.


Wow, i didn't know that. Thanks!

BTW, i believe that Woekshop does level match speakers to the level of the first measured speaker. So in order to avoid clipping, one should play with Zero Level Eq setting, or measure the quitest driver first. Level matching is very useful when measuring small area around the head - the levels are precisely set for this particular position. 

Would love to hear Raimonds input on level matching. And on measuring small area around the head VS the whole cabin


----------



## tonynca

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

So 5 years later.... Is this thing still a very viable auto-eq option?


----------



## subterFUSE

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

The miniDSP with Dirac has some advantages:

1. Far less expensive

2. More channels

3. Easier measurement and target generation process

4. PC and Mac software support

5. Better D/A converters (32 bit Asahi Kasei, same as Helix Pro MK2)

6. No separate DSP needed, everything is in one box.


----------



## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

*subterFUSE*,

Do you use an 8-channel Dirac from miniDSP?

I have an experience with DiracD22 (two channel digital version) which i put before BitOne in the signal chain of my 3 way + sub. Was very satisfied with sound. Then went 5.1 with JBL MS-8. But that was in my previous car. After that i switched to a CarPC with 10 channel audio interface, Reaper as my DSP, linear phase x-overs (FabQ), DTS Upmixing for 5.1 and APL on top of it all. Now i am super satisfied 


At the moment, i am not quite sure that correcting the whole power response is a good idea inside the car. When i measure the whole cabin and get use the correction, i still don't get that desired pinpoint imaging. I guess this is because power response of the whole cabin is different from what is happening around one's head. But when you measure the response around the head, in my car APL finds huge dips in the frequency response and tries to correct them with 8-15db of boost in 150-300hz range which eats all the headroom or creates artifacts. 

I found a workaround - measure and correct the whole cabin, then measure around the head and add some PEQ on top of that. 

*Raimonds*, what are your thoughts on this?


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> At the moment, i am not quite sure that correcting the whole power response is a good idea inside the car. When i measure the whole cabin and get use the correction, i still don't get that desired pinpoint imaging. I guess this is because power response of the whole cabin is different from what is happening around one's head. But when you measure the response around the head, in my car APL finds huge dips in the frequency response and tries to correct them with 8-15db of boost in 150-300hz range which eats all the headroom or creates artifacts.
> 
> I found a workaround - measure and correct the whole cabin, then measure around the head and add some PEQ on top of that.
> 
> *Raimonds*, what are your thoughts on this?


I've had no problem measuring around the head area. Have you tried fixing the dip through the install instead of tuning?


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## tonynca

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> *subterFUSE*,
> 
> 
> 
> Do you use an 8-channel Dirac from miniDSP?
> 
> 
> 
> I have an experience with DiracD22 (two channel digital version) which i put before BitOne in the signal chain of my 3 way + sub. Was very satisfied with sound. Then went 5.1 with JBL MS-8. But that was in my previous car. After that i switched to a CarPC with 10 channel audio interface, Reaper as my DSP, linear phase x-overs (FabQ), DTS Upmixing for 5.1 and APL on top of it all. Now i am super satisfied
> 
> 
> 
> 
> 
> At the moment, i am not quite sure that correcting the whole power response is a good idea inside the car. When i measure the whole cabin and get use the correction, i still don't get that desired pinpoint imaging. I guess this is because power response of the whole cabin is different from what is happening around one's head. But when you measure the response around the head, in my car APL finds huge dips in the frequency response and tries to correct them with 8-15db of boost in 150-300hz range which eats all the headroom or creates artifacts.
> 
> 
> 
> I found a workaround - measure and correct the whole cabin, then measure around the head and add some PEQ on top of that.
> 
> 
> 
> *Raimonds*, what are your thoughts on this?




I love Fabfilter products. I wish I had the patience to run CarPC so I could run any VST I want. You may want to spend a pretty buck on Penteo Perfect Surround if you're using stereo upmixing. I heard it's one of the best in the industry right now. It doesn't have as much artifacts as some of the competition.

Download a free trial of Penteo Perfect Surround and hear the difference.


Sent from my iPhone using Tapatalk


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## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> I've had no problem measuring around the head area. Have you tried fixing the dip through the install instead of tuning?


It's a Range Rover Sport and it has a large central console. I think, it is causing the dip, because when i measure my midbass with the door open and mic close to the driver (30m), the dip goes away. Fixing it with install would mean removing the console 



> I love Fabfilter products. I wish I had the patience to run CarPC so I could run any VST I want. You may want to spend a pretty buck on Penteo Perfect Surround if you're using stereo upmixing. I heard it's one of the best in the industry right now. It doesn't have as much artifacts as some of the competition.
> 
> Download a free trial of Penteo Perfect Surround and hear the difference.


Yeah, the car spent months in the garage while the equipment was installed. 

I tried NuGen Upmix which was not bad, but too CPU-Hungry. DTS is not bad, but i've found that it ruins transients when used with central channel when compared to pure stereo. Quad mode brings some nice ambiance, though.

Will try Penteo - been reading a lot about it.


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## CDT FAN

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

If you point the midbass toward the dome light, does it help with the dip?


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## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



CDT FAN said:


> If you point the midbass toward the dome light, does it help with the dip?


I doubt it. The first dip is at 180hz - at this frequency pointing will not work, the sound radiates in all directions.


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

Is the underside of your dash sealed up?


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## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



LumbermanSVO said:


> Is the underside of your dash sealed up?


Not sure if i quite understand the question, but i did apply some dampening to the insides of the dash, but otherwise there is nothing to seal up. Central console is damped with MLV and decoupling material.

It is quite large, though, which might be causing cancellations:


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## tonynca

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



StabMe said:


> Not sure if i quite understand the question, but i did apply some dampening to the insides of the dash, but otherwise there is nothing to seal up. Central console is damped with MLV and decoupling material.
> 
> 
> 
> It is quite large, though, which might be causing cancellations:




In most cars the under side of the dash is hallow. Sound may travel up there and bounce back down to cancel out. Most of the time it's difficult to seal up the underside because of the pedals. Not impossible but difficult. I'm not even sure if it makes a huge difference. Haven't had a chance to test on my car. 


Sent from my iPhone using Tapatalk


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## LumbermanSVO

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*



tonynca said:


> In most cars the under side of the dash is hallow. Sound may travel up there and bounce back down to cancel out. Most of the time it's difficult to seal up the underside because of the pedals. Not impossible but difficult. I'm not even sure if it makes a huge difference. Haven't had a chance to test on my car.
> 
> 
> Sent from my iPhone using Tapatalk


tonynca is correct, that's what I was talking about.


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## StabMe

*Re: Comprehensive Review: " APL1 " - Advanced DSP / EQ / Phase Correction Unit*

That is a good advice there. I will try to see what i can do and retest.


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## High Resolution Audio

Subbed for reference.


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## Raimonds

Hello Friends,
As you would know, it is very important to do basic loudspeaker`s measurements with confidence and our time is valuable.
I did my contribution to that. Please meet the Real Time version of TDA program - 3 measurements per second, graph latency is about 0.5 second.
Take a look on short videos how to tune up the linear phase crossover in 2 minutes 





and our usual minimum phase crossover in 3 minutes 





You can get the demo version of TDA RT here: http://aplaudio.com/installers/APL_TDA_RT_v002_setup.zip
The installation and quick start guide is available here: http://aplaudio.com/downloads/TDA_RT_Installation_and_Quick_Start_Guide.pdf
Good luck,
Raimonds


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## oabeieo

TDA is very good software..... what a powerful tool.


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## StabMe

Possible to get useful readings inside a car? Does the amount of reflections skew the reading?


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## LumbermanSVO

This is a real life example from my Miata.

Before:









After:


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## oabeieo

LumbermanSVO said:


> This is a real life example from my Miata.
> 
> Before:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> After:


is That with minimum phase crossover?

did you just buy tda or did you get an apl ?

I see the sub GD and otherwise looks about what I would expect.


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## oabeieo

Oh lumberman .... disregard, I know you have apl , I thought it said Miata (ad shrike I was scrolling)


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## LumbermanSVO

I'm the guy that helped you out with an APL 1012 a couple years ago. I have two APL1's and two 1012's, I believe one was the one you were working with. (BTW, I'm looking for a third 1012)

In the Miata I'm using an APL1 (untuned in those photos) and the VXi amp handles the crossovers.

I will be retuning for the first time in year soon because I finally have my own garage to work in.

Edit: Just saw your second reply


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## oabeieo

LumbermanSVO said:


> I'm the guy that helped you out with an APL 1012 a couple years ago. I have two APL1's and two 1012's, I believe one was the one you were working with. (BTW, I'm looking for a third 1012)
> 
> In the Miata I'm using an APL1 (untuned in those photos) and the VXi amp handles the crossovers.
> 
> I will be retuning for the first time in year soon because I finally have my own garage to work in.
> 
> Edit: Just saw your second reply


**** John , I got you practically on speed dial. Lol jk

you saved my a$$ on that install....


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## oabeieo

LumbermanSVO said:


> I'm the guy that helped you out with an APL 1012 a couple years ago. I have two APL1's and two 1012's, I believe one was the one you were working with. (BTW, I'm looking for a third 1012)
> 
> In the Miata I'm using an APL1 (untuned in those photos) and the VXi amp handles the crossovers.
> 
> I will be retuning for the first time in year soon because I finally have my own garage to work in.
> 
> Edit: Just saw your second reply


so is the bronco done?
That thing was looking awesome. Did you ever play with the system


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## LumbermanSVO

I haven't done squat with the Bronco. Since I've helped with your project I've moved across the country twice and bought a house that needs a LOT of work. I have been documenting my house adventures here: https://www.youtube.com/channel/UCaexfxT_9P4Hx-b2Q2aS2Zg


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## oabeieo

Oh dang, it looks like it has fire damage 

are you going to sell one of the 1012s


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## LumbermanSVO

Nah, no fire damage, but lots of water(roof leaks) and termite damage. It is 2700sq ft on .4 acres with a creek, huge backyard, and 1000sq ft garage with a loft and completely open ground floor. I picked it up for $90k a little over a year ago. The back room is perfect for the fully active, all FIR 5.2 system I've been collecting parts for. I just need one more 1012 and I'll have all the hardware I need.


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## oabeieo

LumbermanSVO said:


> Nah, no fire damage, but lots of water(roof leaks) and termite damage. It is 2700sq ft on .4 acres with a creek, huge backyard, and 1000sq ft garage with a loft and completely open ground floor. I picked it up for $90k a little over a year ago. The back room is perfect for the fully active, all FIR 5.2 system I've been collecting parts for. I just need one more 1012 and I'll have all the hardware I need.


Oh dam! 90k that’s nothing ...

i paid 600k for my house and it’s tiny compared to that...but the secret is out , denver is a really cool place...

I’m a bit jelly ..... that looks like a lot of fun


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## cycfari

LumbermanSVO said:


> This is a real life example from my Miata.
> 
> Before:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> After:


I tried out the software today & managed to do my 3 way TA in 30mins.


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## cycfari

Just tried the sofware today & managed to complete my 3 way setup TA in 30 mins!
I just use the GDR & TDA Pl graph as guide do the TA in real time. Really saved a lot efforts.
This is my first try results


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## LumbermanSVO

It's amazing how useful that visualization is, isn't it?

Do you have a x-over at 4k, or is that reflections causing that shift?


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## oabeieo

I don’t use TDA, I use the logarithmic graphs we all know. What do these measurements look in log/Lin scaling. Does anyone have an iR to share from REW or holm, generate all phase plots ?


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## cycfari

LumbermanSVO said:


> It's amazing how useful that visualization is, isn't it?
> 
> Do you have a x-over at 4k, or is that reflections causing that shift?


Yes. It will be impossible for me to get such good TA without it. My car is untreated and full of reflections. I did try to do alignment with the phase graph but it was difficult. Also my laptop can't display all the graph. You will need screen resolution of 1920x1200 to display all.
Currently crossover are 60/400/3k Hz.


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