# TDA (Time-domain analysis) - Measurement Software - Review



## Hanatsu (Nov 9, 2010)

Here's another review which is a continuation of the APL unit I reviewed some time ago (which was planned before my little ragequit on DIYMA)
. All right, here goes:

*Link here: APL-Review.*

*Here's a link to the official homepage: TDA - Time-Domain Analysis*

TDA is a measurement software with the ability to measure how time coherent your system is with a touch of a button. Incredibly easy in other words. It can also view the IR, harmonic distortion 2nd-10th order, AFR (magnitude response). This is a great tool to evaluate phase/time coherency, to troubleshoot and optimize your system.

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The system in the example below:

*2-way + sub (10" sealed, Qtc 1.2, Fsc 58Hz)
*APL1 + MiniDSP 2x4 and subwoofer controlled directly from an Alpine CDE-175R

_*Crossover points: 

Mids, 120Hz LR12 HPF -- 3200Hz LR24 LPF 
Tweeters, 3200Hz LR24 HPF
Sub, 100Hz LR24 LPF_

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*
1. Full system (L+R) - No EQ - No T/A (Initial crossovers set and optimized)*







2D/3D/DFR View. This is basically a mess. No coherency at all and as expected no stage at all. If we take a look at the averaged measured response you can see that the peak around 500Hz correlates with the offset in delay (group delay spike).



2. This is after I've setup T/A by ear and setup EQ for both channels (see the picture above). There's still a jump in relative delay below 200Hz and this is due to the subwoofer blending with the front stage (crossed fairly high). The system sound good/balanced and center staging is great now.

*EQed response and "by-ear T/A"*


To verify if the APL unit did proper corrections I saved my settings and returned the system to its initial setup with no EQ applied and let the APL software do its thing. The result below:

*APL corrections with the initial settings as base*


As it can be seen the delay between 60-200Hz has been greatly improved and it does the job overall very good if you compare it to my tedious tuning session. Male vocals, harmonics of drums etc now stages better with increased perceived depth in stage. The jump in delay around 50-60Hz is the inherited group delay of the sub, it got some peaking due to a fairly high Qts of ~1,2. (In LEAP (modeling software) it displayed a 9ms GD peak @ 55Hz in an anechoic space.) I later improved additionally on this but forgot to save the IR...

Here's the DFR (Delay FR) of the system. This is the same thing viewed as a normal graph if you prefer such a view. 



I assume the little peak at 3,2-3,4kHz is actually the crossover between mids/tweeters. The group delay of a Linkwitz-Riley 4th order filter is 0,5ms in theory so it could be viable.

After setup I confirmed the coherency once again by doing a noise / RTA average in the listening space. See the picture below:

*Correlated vs Un-correlated noise and A/B difference.*


This is the full system playing. Uncorrelated noise is noise recorded in mono, since most vocals and lot of other content often is mono, this represent to a large degree how the mono-FR looks. Correlated noise is affected by incorrect settings in the time domain and large dips show up which are multiples of each other at different frequencies in the magnitude response. Uncorrelated noise is a random generated noise distributed in both channels, so uncorrelated is basically stereo. This isn't affected by standing waves/incorrect T/A settings in the same manner and most often looks far better in an initial setup. By directly comparing them, you can make a rough estimate how much interference there is in the time domain (destructive interference).

For a final test I used my best setting and offset T/A by 1ms, results below:

*T/A offset by 1ms*


*T/A offset by 1ms - Amplitude difference (full system active)*


Again a mess... this is with a perfect L/R FR. T/A is very important to get right as you all probably know.

If you want a software solution that does T/A analysis for you in an easy and efficient manner this is indeed a great program! 

There are several other applications for this software too, troubleshooting incorrect polarity/phase, speaker optimization etc.


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## BlackHHR (May 12, 2013)

Rage Quit LOL


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## claydo (Oct 1, 2012)

Quick question.....does the apl unit work with this program and perform corrections, or is this software independent and just a way to visually display delay? Also, can this software be used to display left right delay, or just the image of your whole system to phase align the mids, highs, lows, and sub? Sorry, more than just a quick question, but the apl unit grabbed my attention early, with price being the only thing holding me back. Does this software apply to the apl, or is it just another offering from the same company?


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## claydo (Oct 1, 2012)

Ok.....asked to quick on at least one....lol. I'm guessing you would take a snapshot of each side individually.......to align the drivers of each side at the mic position, then total system to align left to right. .......hmmmm, I think?


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## Hanatsu (Nov 9, 2010)

claydo said:


> Ok.....asked to quick on at least one....lol. I'm guessing you would take a snapshot of each side individually.......to align the drivers of each side at the mic position, then total system to align left to right. .......hmmmm, I think?


I had left and right tweeters on at the same time. Then left and right mids. Don't bother T/A the drivers to each other on each side. If I'm doing it by ear I simply pull down the highpass on tweeters to the 2kHz range, then turn everything else off. Then adjust T/A until it stages in the center. Repeat for mids till they stage at the same point. Works for me every time and it sounds coherent, the measurements also confirm it. Even though in theory it shouldn't be audible due to the range most tweeters are reproducing (well into the IID-range), it is - at least if the crossover is near or at ~3kHz.

The only problem is that it can be deceiving doing it by ear because you get very easily fooled by any level difference in the higher frequencies. EQ must be precise for my method to work properly. TDA does it without having to bother with this as it only takes the delay into account, it makes the tuning process much faster and less tedious as any proper measurement do.


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## thehatedguy (May 4, 2007)

So looking at the results, could you (a person in general) replicate the results with other measurements/tools?

And how does the whole system go together? APL to TDA to amps?


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## Hanatsu (Nov 9, 2010)

To be honest I've not looked into doing such measurements as these much until now. There are methods to adjust delay by lining up the IR to eachother for example but that won't give you a complete picture of what's going on in the entire range. I'm unsure it's possible to view the relative delay with any widely available software in this manner. Individual channels can be displayed by looking at excess group delay, I do not know how combined channels measurements would look or to be interpreted as of now. TDA is great because it's so straightforward to perform the measurements and leaves little room for misinterpretation.

Sent from my Samsung Galaxy S5 using Tapatalk


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## Kevin K (Feb 11, 2013)

Hanatsu, does the TDA setup need a loopback system to work or will audio out and usb mic work?


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## Hanatsu (Nov 9, 2010)

Kevin K said:


> Hanatsu, does the TDA setup need a loopback system to work or will audio out and usb mic work?


No loopback required, a USB mic will work fine. The only thing you have do is to place the mic at the headrest then press "measure".


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## JoshHefnerX (Jun 13, 2008)

How does this software results compare to using REW as you posted here:
http://www.diymobileaudio.com/forum.../145484-measure-time-delay-t-arta-roomeq.html

Josh


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## thehatedguy (May 4, 2007)

I think the TDA would be more similar to stuff found in the pro world like SMAART and Systune. But those don't have the ability to export files to the APL1 to do phase correction (which I think it does).

The TDA software is a pretty unique way of visualizing delay, phasing, and even speaker resonances.

If I win the lottery, I would like to have a few APL1s.


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## thehatedguy (May 4, 2007)

SMAART 7.4 is $900 for a new license.

TDA is anywhere from $75 to $835. Something similar to SMAART in license is about $316.

Systune is about $500 for the regular and $800 for Systune Pro.

So it's cheaper than SMAART.


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## cajunner (Apr 13, 2007)

thehatedguy said:


> SMAART 7.4 is $900 for a new license.
> 
> TDA is anywhere from $75 to $835. Something similar to SMAART in license is about $316.
> 
> ...



is the level that Hanatsu is using to generate those images, the $835 dollar package, or the bronze level down at $75?


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## thehatedguy (May 4, 2007)

I think the functionality is probably the same at least from the mid license to the top. Though the $75 one might be as well, but at a student discount since it is an academic license.


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## cajunner (Apr 13, 2007)

well, no matter, I'm not paying even $75 for a software plus hardware commitment that doesn't tie my shoelaces...




I am pretty happy with the sound the MS-2 makes, overall... heck. I probably don't even need DSP at all, I know I enjoyed my stereo over the past 30 years, with the majority of those years going no more involved than adjusting treble and bass shelving, haha...

still, a consumer dropping $835 on software just to make pretty graphics is what I'd call hard core.


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## Jepalan (Jun 27, 2013)

Hanatsu, et al - 

A lot of this is over my head, so please be patient with my questions.

I read through the APL website and even tried looking at the patent. For me, the best overall explanation of what TDA, and APL are doing is here -> Acoustic Power Lab :: SPFR

The various descriptions make it sound as if multiple measure points are being used but from what I read above, Hanatsu implies the mic is placed on the head rest and the SW does the rest.

Please clarify this. Is the measurement mic moved around when using the all-in-one APL correction box, or is it kept in one place? If it is kept in one place, then is the SW using time-gates and FIR to create a *virtual* multi-point measurement set?

Again, sorry if above is using technically incorrect terminology, I'm just trying to wrap my head around what this stuff is doing and why it is different.

*** EDIT: I see upon more careful review that I got confused between TDA and APL. Most of my questions were answered in Hanatsu's APL Review thread. ***


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## Jepalan (Jun 27, 2013)

Sorry. I have some additional questions: 

It seems that the APL1 device would be capable of (nearly) perfectly time-aligning a system, even if it is using passive crossovers. i.e. by using an FIR based complex power spectrum (phase & amplitude) measurement and correction, each frequency will be time-aligned by the processor, and the need to time-align individual drivers is minimized (or eliminated, or improved upon)?

Another question: In addition to aligning the primary path to the listener, it sounds like APL will correct for the major reflected paths. Is this true? If so, does it do this by cancelling those paths, or by aligning them at the listening point to sum with the main path?

*** EDIT: I see upon more careful review that I got confused between TDA and APL. Most of my questions were answered in Hanatsu's APL Review thread. ***


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## Hanatsu (Nov 9, 2010)

cajunner said:


> is the level that Hanatsu is using to generate those images, the $835 dollar package, or the bronze level down at $75?


I don't think functionality is affected. It's just how you planning you use it, professionally or not.


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## Hanatsu (Nov 9, 2010)

Jepalan said:


> Hanatsu, et al -
> 
> A lot of this is over my head, so please be patient with my questions.
> 
> ...


Time domain can only be measured in one point in space. Corrections in the FR need to be averaged over a number of points though.


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## Hanatsu (Nov 9, 2010)

Jepalan said:


> Sorry. I have some additional questions:
> 
> It seems that the APL1 device would be capable of (nearly) perfectly time-aligning a system, even if it is using passive crossovers. i.e. by using an FIR based complex power spectrum (phase & amplitude) measurement and correction, each frequency will be time-aligned by the processor, and the need to time-align individual drivers is minimized (or eliminated, or improved upon)?
> 
> ...


The way APL measures and corrects for response irregularities makes it consider reflections in another way than just doing it "the usual way". What is does is basically to take samples of the power response at multiple spots that "creates" the sum at the listening position rather than measuring the sum itself. It does this by an impulse response, not by noise which cannot register any phase/delay information. It does fix most minimum phase regions. Non-minimum phase regions are modal dips for example (which can't be fixed by any type of processing). The minimum phase corrections increases coherency in staging since left and right side is corrected for indiviually, I believe this is the main cause for the increase in perceived depth and focus in the lower midrange.


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## Alextaastrup (Apr 12, 2014)

New TDA version is available now.

APL TDA EQ measurement and equalizer synthesis software:

Uses Time Domain Analysis for an equalizer creation. The detailed equalization of TDA EQ is suitable for any critical loudspeaker applications, in particularl, studio monitors. Output *.fir files go to APL1 unit or APL EP1 VST plugin.


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## crazhorse (Mar 9, 2010)

Alex have you tried the tda eq version? If I remember correctly Raimonds didn't recommend it for car audio use....


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## Alextaastrup (Apr 12, 2014)

crazhorse said:


> Alex have you tried the tda eq version? If I remember correctly Raimonds didn't recommend it for car audio use....


No, I have not. But idea to send EQ file directly to APL (including TA) is very attractive.

I would agree with Raimonds that the Workshop is more accurate and more powerfull for EQ task in a car, as you are not bend to the listening position as it is the case of TDA.

My experience is that it is rather difficult to achieve the same repeatibility with TDA compared to Workshop. If you use both - then you have all the necessary info to tune the car in the best way


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## Alextaastrup (Apr 12, 2014)

It was fun to see how just 1ms can destroy the sound image. I made also some funny things, trying first to delayboth front channels against each other with 360cm (max possible in the present HU) and to see how they will play:

http://i430.photobucket.com/albums/qq28/Alexander_Souproun/Right 0cm_3D_zpsalw9jdpb.jpg?t=1451936064

Then by reducing the mutual delay I moved to the "image position" of the optimum. In my case (3way passive + sub in the trunk) this was achieved at 28cm (again - we are talking about very rugh adjustment, which accuracy is limited by HU).


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## Hanatsu (Nov 9, 2010)

Alextaastrup said:


> New TDA version is available now.
> 
> APL TDA EQ measurement and equalizer synthesis software:
> 
> Uses Time Domain Analysis for an equalizer creation. The detailed equalization of TDA EQ is suitable for any critical loudspeaker applications, in particularl, studio monitors. Output *.fir files go to APL1 unit or APL EP1 VST plugin.


Sounds interesting!

I have done some more work with the APL/TDA system and will post it within a few days but I haven't seen the new update yet, hope Raimonds lets me play around with it


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## Alextaastrup (Apr 12, 2014)

Some more pictures from the last tests with TDA:

Pic1. Mutual cancelling of the front channels (appr. 260, 460, 800, 1600Hz) and influence of the infrasonic filter.

Pic.2 - Best possible dfr for the present install (3way passive)

Pic.3 - 2D delay presentation



As one can see, cancellations on the first pic. are gone. Without infrasonic filter the sub became "closer" to the front. Sounds more tight and accurate.


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## claydo (Oct 1, 2012)

Ok gentlemen, I need help in figuring out what I'm doing wrong. I went to the apl/tda website, and decided I'd try the tda trial software.....so I was informed I needed to download some software, don't remember the name......version 2013 8.1mat play or sumthin.... and I followed the link and did that....then I downloaded the trial version of tda. The only evidence I see of tda on my computer is the installer program....I've installed a number of times yet still no tda on my computer that I can find.....ugh. Can someone please walk me through exactly what they've done to make this work on their computer? I hope so, I've read the directions on the tda site, and I'm obviously missing something. Please someone help this barely computer literate feller out!


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## Alextaastrup (Apr 12, 2014)

In order to use TDA you need to download and install Mathworks Matlab compiler runtime (MCR) 2013a 8.1 according to your operating system type, Windows 32 or 64bit!

Please check what version of windows you have on your PC - 32 or 64. I have never had issues during installation of this program on XP.


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## claydo (Oct 1, 2012)

Ok....I did that windows 7 64 bit......I did this before I even downloaded the tda software. Anything I could be missing?

I did get a message saying the tda may not have installed correctly....mtry again with recommended settings....but still no good......ugh.


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## Hanatsu (Nov 9, 2010)

Tried uninstall then reinstall? Try starting the program as administrator.


Sent from my iPhone 6 using Tapatalk.


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## claydo (Oct 1, 2012)

I will try when I get home today....thanks!


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## Beckerson1 (Jul 3, 2012)

Hanatsu said:


> Tried uninstall then reinstall? Try starting the program as administrator.
> 
> 
> Sent from my iPhone 6 using Tapatalk.


I usually have to run as Admin to get mine to work so definitely worth the try


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## Babs (Jul 6, 2007)

Hanatsu said:


> No loopback required, a USB mic will work fine. The only thing you have do is to place the mic at the headrest then press "measure".



By Thor's Hammer! I must try it! Only I bet since my darn laptop sound card is a goner and won't output sound I'm screwed I bet. 


Sent from iPhone using Tapatalk


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## Beckerson1 (Jul 3, 2012)

Babs said:


> By Thor's Hammer! I must try it! Only I bet since my darn laptop sound card is a goner and won't output sound I'm screwed I bet.
> 
> 
> Sent from iPhone using Tapatalk


ya you need output from the laptop.


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## Hanatsu (Nov 9, 2010)

My goal with my new build is to produce a TDA plot that shows 0ms delay at all frequencies 

Might sound impossible but I'd like to try, with properly implemented FIR processing, the low frequency group delay can be removed to a large degree...


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## brumledb (Feb 2, 2015)

claydo said:


> Ok gentlemen, I need help in figuring out what I'm doing wrong. I went to the apl/tda website, and decided I'd try the tda trial software.....so I was informed I needed to download some software, don't remember the name......version 2013 8.1mat play or sumthin.... and I followed the link and did that....then I downloaded the trial version of tda. The only evidence I see of tda on my computer is the installer program....I've installed a number of times yet still no tda on my computer that I can find.....ugh. Can someone please walk me through exactly what they've done to make this work on their computer? I hope so, I've read the directions on the tda site, and I'm obviously missing something. Please someone help this barely computer literate feller out!


Mine was doing the same thing, you need to extract the files from the zip, then just click on the little TDA icon like normal.


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## claydo (Oct 1, 2012)

brumledb said:


> Mine was doing the same thing, you need to extract the files from the zip, then just click on the little TDA icon like normal.


Awesome....I'll try that, so far no luck, thanks!


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## Elgrosso (Jun 15, 2013)

claydo said:


> Ok....I did that windows 7 64 bit......I did this before I even downloaded the tda software. Anything I could be missing?
> 
> I did get a message saying the tda may not have installed correctly....mtry again with recommended settings....but still no good......ugh.


I had this message too but with APL workshop, it was the wrong matlab thing installed. But it seems you have the right one (8.**).
With TDA I have a popup every time I start, something about admin rights, but it works.


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## Hanatsu (Nov 9, 2010)

Did you install it as admin too? Try 32bit version even if you use 64bit. Also did you install matlab before tda?


Sent from my iPhone 6 using Tapatalk.


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## claydo (Oct 1, 2012)

I did, but at first I had the wrong version of matlab.....so I uninstalled the wrong version, as well as the start up file for tda......got the right matlab, then went back and got tda again. I didn't get the chance to meet with it yesterday, so maybe this evening I will drag the laptop back out and try again...........thanks guys for all the suggestions, I may be back tonight if it doesent pan out......lol. I didn't specifically make any choices about admin.....is this something I need to go to another menu to choose as an option?


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## brumledb (Feb 2, 2015)

claydo said:


> I did, but at first I had the wrong version of matlab.....so I uninstalled the wrong version, as well as the start up file for tda......got the right matlab, then went back and got tda again. I didn't get the chance to meet with it yesterday, so maybe this evening I will drag the laptop back out and try again...........thanks guys for all the suggestions, I may be back tonight if it doesent pan out......lol. I didn't specifically make any choices about admin.....is this something I need to go to another menu to choose as an option?



Yes, there is a specific option for opening it as admin. Right click on the TDA icon that opens the program and you will get a menu of options. You will see an option to open/run it as Admin. 
I had to extract the files from zip and run it as admin. When I only extracted, the program would open but not let me measure. 


Sent from my iPhone using Tapatalk


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## claydo (Oct 1, 2012)

brumledb said:


> Yes, there is a specific option for opening it as admin. Right click on the TDA icon that opens the program and you will get a menu of options. You will see an option to open/run it as Admin.
> I had to extract the files from zip and run it as admin. When I only extracted, the program would open but not let me measure.
> 
> 
> Sent from my iPhone using Tapatalk


****.....I haven't even gotten an icon....lol. The only thing I can find on my computer after the download related to tda/apl is the thing that starts the download again.....


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## brumledb (Feb 2, 2015)

Ok I'll just do it step-by-step:
1. Find the zip file you downloaded. It will be "APL_TDA_v008_64b_demosetup".
2. Right click on it, select extract.
3. Select where you want the extracted files to go.(just make sure you remember where you are sending them so you can find them).
4. Find the files you just extracted.
5. One of the files you extracted will be "APL_TDA_v008d_64". The 64 is assuming you are running 64 bit as opposed to 32 bit.
6. Right click on that file.
7. Select "run as administrator"

Give that a shot.


Sent from my iPhone using Tapatalk


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## claydo (Oct 1, 2012)

brumledb said:


> Ok I'll just do it step-by-step:
> 1. Find the zip file you downloaded. It will be "APL_TDA_v008_64b_demosetup".
> 2. Right click on it, select extract.
> 3. Select where you want the extracted files to go.(just make sure you remember where you are sending them so you can find them).
> ...


Thanks brother........I'm fixing to eat a late supper and then I'll be dragging out the lappy to give this a shot......me thinks the unzipping has something to do with my conundrum, I'll let ya know how it works out!


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## claydo (Oct 1, 2012)

Woohoo!!

Thanks to all who offered advice. We have success!



Now, is my mic cal file needed at all for the measurements I'll be taking? I'm thinking no, but figured I'd ask......

Plus any more tips for the measuring would be appreciated....

Btw this isn't my car in the pic.....just the lappy speakers as I tested to see if it would measure.....seems pretty straight forward.


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## Alextaastrup (Apr 12, 2014)

claydo, congrats!

Waiting results from your car. Try first one channel (f.ex. left front) + subwoofer.
3D pictures are more exciting to look at, but I prefer 2D as they give more precise information regarding group delays.

It is funny always to null all the TA settings and to check actual delay of both fronts from the listening position. Then - delay each speaker in order to obtain the simultanious arriving time. To connect the sub is typically the biggest problem. Sometime, phase switch is necessary along with selecting of the most optimal filter orders between the sub and mids.

Do not forget that it is possible to rotate 3D-images. This option could give you some additional info.


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## Babs (Jul 6, 2007)

Beckerson1 said:


> ya you need output from the laptop.



I've got laptop output now. You guys coming to the NCSQ meet, this would be cool tech fodder for a little seminar.


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## claydo (Oct 1, 2012)

One thing that surprised me was how accurate my "by ear" t/a was. Of course there is room for improvement, but I'm having trouble relating the p99's adjustments to what I'm seeing on the screen.


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## Babs (Jul 6, 2007)

claydo said:


> One thing that surprised me was how accurate my "by ear" t/a was. Of course there is room for improvement, but I'm having trouble relating the p99's adjustments to what I'm seeing on the screen.


I still wanna try a complete 80PRS tune verses the Helix.. The Helix continues to win. Would love to play with the 99RS's more extensive EQ. So you playing with the trial version of this software? 

This would be for all.. I am perplexed with TA and our beans.. What I mean is our "mic's" on our heads have two, not one, and they're several inches apart. This is the conundrum I'm dealing with concerning a measured TA tool verses ear alignment. Were it speakers very far away and more in-front, instead of car with wider speaker placement and short distances, I could fathom that a single mic point would be pretty darn spot on, but when drivers are so wide as they are in car and your ears are also relatively wide apart, how's it work?


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## claydo (Oct 1, 2012)

Yup, playing with the trial version.....I have yet to improve much from my initial reading.....need to learn more about what I'm seeing I reckon.....

It seems to me when I go moving the blackness of the trace? (For lack of a better term) It will lose its symmetry and become squiggly....lol, technical terms......then it doesent always move in correlation with my adjustments.....it seems pioneer has some funkyness in its t/a adjusments, or I need to read up somewhere on what exactly the tda is seeing.....


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## Babs (Jul 6, 2007)

claydo said:


> Yup, playing with the trial version.....I have yet to improve much from my initial reading.....need to learn more about what I'm seeing I reckon.....


Dunno the resolution of your 99RS delay increments, but might be a factor if splitting hairs that much.


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## claydo (Oct 1, 2012)

I'm just glad my settings were proven to be really close....that was satisfying......and it's much easier to see than the impulse measurements in rew......


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## Alextaastrup (Apr 12, 2014)

claydo said:


> I'm just glad my settings were proven to be really close....that was satisfying......and it's much easier to see than the impulse measurements in rew......


Agree 100%. TDA gives much more informative results. FR maybe not so accurate (compared to Workshop/APL), but might give all necessary information on phase problems at the XO point. Changing the filter order helps to eliminate the dips. It is easy and quick to do with TDA: switch - test - switch - test... All done just in halv an hour.

Experience shows that the higher filter order results in a bigger group delay, which is more difficult to struggle against. With some capacity limits (10ms of HU and 5ms of APL1) I simply had to choose the first order at much lower XO point for the sub (40Hz), which might be very unusual. Many people use normally 24dB/oct at 80 or even 100Hz. After measurements with the TDA it came out that it was a bad choice for my present install. It was not possible to come to this conclusion without TDA software.

Null delay at DFR-graph (for mids and tweeters) together with a smooth FR at XO points (both front channels at the same graph) - might be a goal when optimizing TA with the help of TDA. Yes, we do not hear phase problems well, that is why a reliable measuring tool is a good help in this case. Above appr. 4kHz correction might be done by the sound volume instead of delaying in time. This is even more important for the passive XO.

Take a look on my first picture in the post No.26. it is easy to observe cross-cancelling at several frequencies (both fronts are shown there). Slight adjustment of TA made this problem much less. You may try this in your car.


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## Elgrosso (Jun 15, 2013)

Alextaastrup said:


> ...It is easy and quick to do with TDA: switch - test - switch - test... All done just in halv an hour....


Very interesting!
So you process here only involve measurements and TA tweaking?


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## brumledb (Feb 2, 2015)

These are my results with using Tape Measure/Tracerite for T/A. 
Tweeters-- 2750hz
Mids--406hz-2750hz
MB's--93hz-406hz

Everything is on L/R 24's.

The 1st pic is the entire system W/O Subs, 2nd pic is Left side w/o Subs, 3rd pic is right side w/o subs. 

So, what should be my plan of attack to fix these T/A issues?








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## sq2k1 (Oct 31, 2015)

This is some interesting material...I have yet to dabble into this much detail when dealing with my system...although I am still building it as of this time.I will definitely keep an eye on this thread.


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## Elgrosso (Jun 15, 2013)

I will soon need this too.
Can you adjust the ms window for the graph on the demo? (looks like the sub is out)


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## brumledb (Feb 2, 2015)

I had the sub muted.


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## Elgrosso (Jun 15, 2013)

Opps


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## Hanatsu (Nov 9, 2010)

brumledb said:


> I had the sub muted.



Hah yeah... Those measurements looked really messed up 


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## thebookfreak58 (Jun 18, 2012)

Quick guide on how to read the graphs??

And what to adjust?


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## Hanatsu (Nov 9, 2010)

The 2/3d view is simply frequency vs delay in ms. 

If it's off the the L/R timing is incorrect. Correct this with T/A.

There can of course be other problems like crossovers.


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## brumledb (Feb 2, 2015)

What is the best process for using TDA? 
Should I mute everything but tweeters and align them, then add mids? 
Or try to align entire left side and then right side and then align the two sides together?



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## strohw (Jan 27, 2016)

Before you continue on that path you should install HolmImpulse and setup your T/A with that. Then go back and check everything with TDA to see how it looks. Just for fun of course. =]


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## Hanatsu (Nov 9, 2010)

You place microphone clamped between the seat and headrest. Don't be in the car, run all speakers at the same time. Full system, left and right sides + sub. There you'll see the complete time coherency of the system.

You could go left and right side only + sub too if you are troubleshooting for something.


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## brumledb (Feb 2, 2015)

I actually have holmimulse, just haven't had time to learn how to use it.


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## brumledb (Feb 2, 2015)

Hanatsu said:


> You place microphone clamped between the seat and headrest. Don't be in the car, run all speakers at the same time. Full system, left and right sides + sub. There you'll see the complete time coherency of the system.
> 
> You could go left and right side only + sub too if you are troubleshooting for something.



Start at with 0 time delay and try to "walk" it in from there? And assume that it would be the driver's side that needs delaying?
Do you try to align tweeter, then move to mid, then midbass, then sub?


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## Alextaastrup (Apr 12, 2014)

brumledb said:


> I had the sub muted.


I would start to look at AFR graph. Improving the frequency response of the selected channel (left or right) by EQ might make the time delay more smooth. Then test once more time and open DFR graph to define values of time alignment needed for every speaker. The goal is to optimize the system in the way when sound from different speakers will arive at the same time. I am talking here about impulse start (arriving start time), not peaks , in order to avoid pre-ringing and the low end. It is important for natural sounding of your system. For TW, mids and MB try to make DFR curve close to 0ms. For subwoofer - the sound should arrive simultaniosly with other speakers, not before. Typically it is much later for SW placed in a trunk, and even worse for a complicated box like 4. or 6. order bandpass.

What are TA settings for these graphs?


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## Elgrosso (Jun 15, 2013)

Babs said:


> ... I am perplexed with TA and our beans.. What I mean is our "mic's" on our heads have two, not one, and they're several inches apart. This is the conundrum I'm dealing with concerning a measured TA tool verses ear alignment. Were it speakers very far away and more in-front, instead of car with wider speaker placement and short distances, I could fathom that a single mic point would be pretty darn spot on, but when drivers are so wide as they are in car and your ears are also relatively wide apart, how's it work?


About this, I will try tomorrow 2 different points, left / right ears with me in the car, just to see the difference.

So far I just did one point in front of the nose:


No manual Ta with ms8, but I'll play with different ms8 calibration too.


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## brumledb (Feb 2, 2015)

Wow... That's your first try?!? I have spent HOURS trying to align and haven't gotten anything nearly that good. I'll post my current best later. 


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## strohw (Jan 27, 2016)

brumledb said:


> Wow... That's your first try?!? I have spent HOURS trying to align and haven't gotten anything nearly that good. I'll post my current best later.
> 
> 
> Sent from my iPhone using Tapatalk


He's using ms8


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## Elgrosso (Jun 15, 2013)

brumledb said:


> Wow... That's your first try?!? I have spent HOURS trying to align and haven't gotten anything nearly that good. I'll post my current best later.
> 
> 
> Sent from my iPhone using Tapatalk


Ms8 and APL, so it's really not me 
But check that, left and right:





Sub could be better on both, i have somehting strange on the right woofer, and some ringing on the right tweeter?
I'll try some more with ms8 on/off and apl on/off.


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## brumledb (Feb 2, 2015)

Yeah I know he is using the MS8 but that is still really impressive now that I have experienced how hard it is to get those frequencies to line up. Especially the sub, I am out of delay to add on my tweets and still like 20 seconds out on the sub. I must still not be doing something properly.
Ah, so you are using the APL already? And that is adding delay to specific frequencies, correct?
I haven't started using my APL yet and trying to do it just by TDA.



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## Elgrosso (Jun 15, 2013)

brumledb said:


> Yeah I know he is using the MS8 but that is still really impressive now that I have experienced how hard it is to get those frequencies to line up. Especially the sub, I am out of delay to add on my tweets and still like 20 seconds out on the sub. I must still not be doing something properly.
> Ah, so you are using the APL already? And that is adding delay to specific frequencies, correct?
> I haven't started using my APL yet and trying to do it just by TDA.
> 
> ...


Yes it does fix the ir, but what part is due to ms8 and what part is due to APL, I should learn soon.
So you got your, don't wait, even in bad hands like mine it's really cool!


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## Hanatsu (Nov 9, 2010)

I have to stress this:

DO NOT SIT IN SEAT WHILE MEASURING. DON'T TOUCH THE MICROPHONE.

Clamp it in headrest, in the middle where your head is normally. If you move the mic even an inch the measurement will be messed up. If you are aiming for repeatable results while correcting time coherency the mic must be absolutely stationary.

Elgrosso, The results you seeing on right side are probably due to destructive interference. I assume there's dips in the frequency response (AFR) at the same spots. Is this a 2 or 3-way? If it's a door mid it's perfectly normal. A small dedicated midrange should do better if placed optimally. Where is the crossovers?


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## Alextaastrup (Apr 12, 2014)

Even if it is door installment of the mids, it does not explain the difference between left and right channels. Interesting to check FIR filters upload for the right channel. Wrong EQ by ms8? Look also on XO points and filter orders. Just to eliminate possible error source.

Can you repeat the measurement for the right side?


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## Elgrosso (Jun 15, 2013)

Hanatsu said:


> I have to stress this:
> 
> DO NOT SIT IN SEAT WHILE MEASURING. DON'T TOUCH THE MICROPHONE.
> 
> Clamp it in headrest, in the middle where your head is normally. If you move the mic even an inch the measurement will be messed up. If you are aiming for repeatable results while correcting time coherency the mic must be absolutely stationary.


Ok that makes sense, will do next time (damn' I don't have a headrest )
But what about picking a "repeatable" point, that is closer to each ear?
Doesn't it make sense to use a point around left ear for left channel, and right ear for right channel ? 




Hanatsu said:


> Elgrosso, The results you seeing on right side are probably due to destructive interference. I assume there's dips in the frequency response (AFR) at the same spots. Is this a 2 or 3-way? If it's a door mid it's perfectly normal. A small dedicated midrange should do better if placed optimally. Where is the crossovers?


It's a 3 way, mids on dash, and the interferences here are near the cross over point: 800Hz/24db between woofer and midranges (even if it looks like 500Hz here).

I didn't "REW" this setup yet, but usually I have more a peak around there.

I re-did them this morning, so mic in hand I probably moved few mm (not inch)
right ear/right channel:

left ear/left channel:


But they are really different than yesterday, around the sub.
Maybe I had a different sub setting I don't remember.
Next measures will be more serious, here it was just to see how this works.
But probably nothing soon, big rain last few days, and my old car is a bit leaky... had to remove the gti to protect them :/


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## Hanatsu (Nov 9, 2010)

No. Place it in the absolute center, no different positions for left/right


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## Hanatsu (Nov 9, 2010)

If you got the option in the Ms8, delay the entire system EXCEPT sub by 15ms.


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## thehatedguy (May 4, 2007)

You do not have that ability.


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## Alextaastrup (Apr 12, 2014)

Much better this time. I will remake the test for both fronts - to see how big TA values should be for their alignment (both on one graph). In any case, both fronts have to be delayed appr. 16-18 ms for better connection with the sub.


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## Hanatsu (Nov 9, 2010)

If given the option I sometimes cascade delays from headunit into DSP by using 2 different outputs. Gives you more room to work with delays in the LF.


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## Elgrosso (Jun 15, 2013)

Hanatsu said:


> No. Place it in the absolute center, no different positions for left/right


OK!



thehatedguy said:


> You do not have that ability.


yep,
but I have a 180 switch on sub maybe?



Alextaastrup said:


> Much better this time. I will remake the test for both fronts - to see how big TA values should be for their alignment (both on one graph). In any case, both fronts have to be delayed appr. 16-18 ms for better connection with the sub.


Thx Alextaastrup,
this soft is easy in fact, the easiest to read maybe.
Anyway I think I'll try the Cdsp soon to have more control (after the rain )


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## Hanatsu (Nov 9, 2010)

Elgrosso said:


> but I have a 180 switch on sub maybe?


At 90Hz a 180deg swap would equal ~5.5ms if the sub is 180deg out of phase right now... Unless you got a large null at the crossover lol.


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## Elgrosso (Jun 15, 2013)

No such null 
Well I deal with this later, in fact I'm about to remove the sub box behind me and put the rear seat back. (just need to find some decent 6"/7 sub to put in the two hidden oem enclosures)


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## brumledb (Feb 2, 2015)

This is the best I have been able to achieve. But as you can see my sub is 20+ ms out and I am out of delay on my tweeters. The Helix only goes to 15.6ms. So any suggestions on what I should try?
Right now I using LR 24's for all crossovers. Should I try using a lower order crossover and maybe Bessel or Butterworth instead of LR?








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## Hanatsu (Nov 9, 2010)

Acoustic crossovers are what matters, see the crossovers in your DSP as response shaping. There seem to be sub/mid integration issues as well as T/A and/or L/R FR inconsistancies. I would do individual measurements on all driver by RTA/noise so you get as much averaging as possible. Then compare all the individual measurements to a full left side+sub and a full right side +sub, check if all drivers sum at crossovers. Check actual slopes. Do a sweep of left side and one of the right side in RoomEQ for example, check excess group delay for large peaks which indicates destructive interference.

If the L/R EQ is set correctly you should be able to set T/A by ear very easy with correlated pink noise. I can measure my car tomorrow and show you why some of these issues occur.


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## brumledb (Feb 2, 2015)

Ok, sounds like I just need to start back at step one. I want to change my house curve anyways. I will go back and make sure I have everything dialed with with EQ before trying to utilize TDA.


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## cvjoint (Mar 10, 2006)

Hanatsu said:


> I have to stress this:
> 
> DO NOT SIT IN SEAT WHILE MEASURING. DON'T TOUCH THE MICROPHONE.
> 
> ...


Great thread, and an important venture in an important topic. 

I've worked with CSDs in the past but the lack of software to sum up time domain responses from multiple mic positions is a huge drawback. The only way to receive an input signal unbiased is to average many many times from correct positions, with your body in the seat. That way your measurement is centered on the "true" signal your brain receives and measurement error is mitigated through averaging. 

If the "measurement is messed up" by moving one inch, you have big problem. The solution is not to keep the mic fixed but to implement some form of averaging and to place the mic correctly around your years when your head is next to it. 

I have no doubt that you measurement is correct for that location and an empty car, but whether that is relevant to what you hear when in your seat is ultimately a very important topic. Even if you repeat the measurement exactly by mimicking your previous test position it does not mean your results are accurate, just that the software has high accuracy. You still have to feed it the right signal.


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## cvjoint (Mar 10, 2006)

Elgrosso said:


> Ms8 and APL, so it's really not me
> But check that, left and right:
> 
> 
> ...


Check your vertical axis. It appears you changed the axis settings between left and right. The software likely gives you the option to focus on certain frequencies and you may have done so not knowingly.


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## Hanatsu (Nov 9, 2010)

cvjoint said:


> Great thread, and an important venture in an important topic.
> 
> I've worked with CSDs in the past but the lack of software to sum up time domain responses from multiple mic positions is a huge drawback. The only way to receive an input signal unbiased is to average many many times from correct positions, with your body in the seat. That way your measurement is centered on the "true" signal your brain receives and measurement error is mitigated through averaging.
> 
> ...


TDA is some kind of mashup between a CSD and Group Delay plot.

You are correct that you need to do a lot of averaging when doing CORRECTIONS in the frequency response.

This is different. We are measuring ONE point in space, time domain measurements are always and only available at one specific point in space. If you are sitting in the car while doing time domain measurements or impulse aligning, it will most likely be messed up because the head cause "shadowing". It can cause significant changes in the frequency response and it will impact the phase response / time domain as well. You are also correct that we need to correlate this with what we are hearing, the head shadowing is a distortion in the measurement we don't want, we don't perceive the sound that way, there is always acoustic crosstalk. I've done extensive testing into this and found that an empty car with the mic is usable for two types of testing.

1. Time domain measurements.

2. Subwoofer measurements (matters very very little if you sit in the car or not, no averaging is required either).

Don't understand what you mean by "feeding it the right signal" though. TDA creates the sweep and measures at the same time.


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## cvjoint (Mar 10, 2006)

Hanatsu said:


> TDA is some kind of mashup between a CSD and Group Delay plot.
> 
> You are correct that you need to do a lot of averaging when doing CORRECTIONS in the frequency response.
> 
> ...


It GD and CSD are basically the same thing no? I can see this platform has various ways to show you a plot but the information contained should be the same. The 2D plot is very nice.

As long as you can move the mic and collect another series of time domain measurements (and they should be different) then averaging is a matter of "how to" not "is it possible?" In this case if you could export your time measurements in a raw format from multiple mic positions you could average them. 

Ok, if you restrict your use to TA and subwoofer measurements then I agree, you are taking in the right signal. Go on.


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## Hanatsu (Nov 9, 2010)

Group delay is the negative slope of the phase response. A CSD displays ringing (decay) in the magnitude response (derived from the IR). Both depict linear distortion. The 2D/3D view is kinda special, I haven't seen a program that combines delay and decay/ringing in the same plot. It's certainly useful since you get data that would require way more work to attain otherwise.

Yes you can average them that way but the thing is, what are you gonna use it for? 

We need some kind of "zero point" to use as reference, it can be useful to move the mic and see if some issues goes away but to attain repeatability you would need some kind of jig so you can set the mic at fixed positions so you can eliminate an altered mic position while troubleshooting an A vs B measurement. We must know if we are applying corrections to fix the mic position or the speaking tuning, that's the reasoning behind my statement 

APL Workshop is the exact opposite of TDA, there you average hundreds of points in the sound power domain.


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## Babs (Jul 6, 2007)

Finally loaded this bad boy up to mess with it. Here goes nothing.


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## Hanatsu (Nov 9, 2010)

I have a few plots to upload tomorrow, measured my new build. Right side measured almost flat from 50Hz to 20kHz +/- 2ms, with only level matching and T/A. No EQ at all. Was actually surprised how good it looked, only two minor hiccups around 1-2kHz for some reason.

Edit: I had them on this computer lol.

No tuning at all, no T/A, No level matching. Right side only.



Level matching and T/A applied. No EQ. APL bypassed.

That ringing around 400Hz is due the high Q small pods of the midrange drivers. I might have to vent them better... You can also see the high Q peak for midbass enclosures around 130Hz.



Sub got pretty high GD even though it's in a large sealed box.


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## Elgrosso (Jun 15, 2013)

Nice, where do you cross your mids here, 200hz??
And how did you change the time window on the graph? Or I guess you have the full version now


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## Elgrosso (Jun 15, 2013)

cvjoint said:


> Check your vertical axis. It appears you changed the axis settings between left and right. The software likely gives you the option to focus on certain frequencies and you may have done so not knowingly.


Here they're really almost the same.
I have trouble managing the view on this, it jumps from front 2d to 3d with the slightest trackpad move. Maybe it's // desktop, or just windows...


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## Hanatsu (Nov 9, 2010)

Elgrosso said:


> Nice, where do you cross your mids here, 200hz??
> And how did you change the time window on the graph? Or I guess you have the full version now



80/200/3700Hz.

There's a box where you can enter the time window. Yep I'm running the "full" version


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## Elgrosso (Jun 15, 2013)

These are the Eton right? I saw that you had trouble in an old post, when crossed at 160hz.


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## Babs (Jul 6, 2007)

K so am I doing something wrong? Or will it simply not allow seeing the TDA plot or 3D plot in demo mode?











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## brumledb (Feb 2, 2015)

Something isn't right. It will let you see the 3D and 2D graphs in the demo mode.


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## Hanatsu (Nov 9, 2010)

Something is wrong... Looks like the install failed or something. Did you install the Matlab compiler?


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## Babs (Jul 6, 2007)

Yep. Figured it out. Had to redownload. Now to do some measuring when I can get a chance in a little bit. First plot I discovered my mic had fallen. Yay. Now to get kids to bed and try again. 


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## strohw (Jan 27, 2016)

Finally, tried this app but I'm not getting consistent results with it. Using a uca202 sound card and get consistent repeatable results in rew and holmimpulse. However, with this app one second it's showing +/- 1ms on my 20-80hz and the next it's showing a +5ms smear over a portion of the same range.


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## brumledb (Feb 2, 2015)

strohw said:


> Finally, tried this app but I'm not getting consistent results with it. Using a uca202 sound card and get consistent repeatable results in rew and holmimpulse. However, with this app one second it's showing +/- 1ms on my 20-80hz and the next it's showing a +5ms smear over a portion of the same range.


Are you staying in the car for the measurement? If so, try sticking mic into the headrest and take some measurements without being in the car. Hanatsu has mentioned that measuring while sitting in the car will cause inconsistent measurements.


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## strohw (Jan 27, 2016)

I have the mic clamped in the headrest roughly where the center of my head would be. I am sitting in the back seat of my crew cab. That's mainly because I don't have a long enough cable to run the laptop outside the truck.


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## Babs (Jul 6, 2007)

Remember I believe this tool assumes your tweets and mids are darn close to level and EQ matched. This may have an affect I'm sure. 

So I messed with it quite some time and not so positive I have it mastered but was able to achieve this.

Two way 
SB29/XSPTW 24db @ 1907hz LR
SB17 at 80-2khz roughly (split)
JL 12TW1 @ LR4 75hz



















So I'll have to say I'm impressed with the stage and coherence. From history with the tune I expected the sub to be all kinds of crazy out of phase and didn't really know what to expect. I'd have to say I'm a believer. Though was unable to get any better than the above plot. I think a lot of the troubles are simply modal and reflection related. And it does really come down to mic placement. 

Hanatsu and others I'm wide open for suggestions. 


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## brumledb (Feb 2, 2015)

Babs said:


> Remember I believe this tool assumes your tweets and mids are darn close to level and EQ matched. This may have an affect I'm sure.
> 
> So I messed with it quite some time and not so positive I have it mastered but was able to achieve this.
> 
> ...


Looking good. I would be curious to see how your sub delay would change by using a 2nd order butterworth.


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## Babs (Jul 6, 2007)

brumledb said:


> Looking good. I would be curious to see how your sub delay would change by using a 2nd order butterworth.



Hmm interesting. I'll try it when I get a chance. Yeah it's hard to tell what "good" should look like since we know there's so much destructive phase craziness in car. I could only tweak, measure, tweak and see if it improves or not. I guess it's a completely trial and error iterative thing.

And isn't it strange my temporary sub is literally in the back seat, though by all accounts measuring it acts like it's in the car behind me. Is it the crossover doing this?


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## thebookfreak58 (Jun 18, 2012)

So with this tool, measure the entire system all channels playing? Or one side at a time?

Basically adjust T/A on each driver till it locks in?


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## Babs (Jul 6, 2007)

thebookfreak58 said:


> So with this tool, measure the entire system all channels playing? Or one side at a time?
> 
> Basically adjust T/A on each driver till it locks in?



I ran all drivers. You can tell through the frequency region if tweets are out or mids are out etc. So if pairs (left/right) or sides (tweet/mid/midbass/sub) are out. 

I guess the goal is to get all to one perfect vertical line at 0ms.


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## Alextaastrup (Apr 12, 2014)

From the practical point of view and based on psychoacoustics: 1-2ms should be just fine. For tweeters the magnitude (volume of the sound) is more important, but keeping them also within the abovementioned band will not spoil the sound stage .

It is more critical with the low end, where sub enclosures have their own generic delays: Sealed is the best, 6th bandpass - worst. Typical delay of a vented port box - 20-30ms - just to mention one. TA left/right channels might not feet 100% with the subwoofer, so it is a compromise, as always.


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## strohw (Jan 27, 2016)

Using that idea for the sub visualized in this thread helped me get much better integration. In my setup the sub is only 40" away which is roughly the same length as the left mid.

I was always testing 0+ ms. After seeing the results here I tested the other way and started at 0 and delayed everything else. I had 12ms left that I could use and after doing a lot of testing I found -8.5ms measured the best in REW. I sat there and measured 1ms at a time and each measurement showed a pretty significant change in the 70-100hz range where the subs/mids integrate.


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## Babs (Jul 6, 2007)

strohw said:


> Using that idea for the sub visualized in this thread helped me get much better integration. In my setup the sub is only 40" away which is roughly the same length as the left mid.
> 
> I was always testing 0+ ms. After seeing the results here I tested the other way and started at 0 and delayed everything else. I had 12ms left that I could use and after doing a lot of testing I found -8.5ms measured the best in REW. I sat there and measured 1ms at a time and each measurement showed a pretty significant change in the 70-100hz range where the subs/mids integrate.





Alextaastrup said:


> From the practical point of view and based on psychoacoustics: 1-2ms should be just fine. For tweeters the magnitude (volume of the sound) is more important, but keeping them also within the abovementioned band will not spoil the sound stage .
> 
> It is more critical with the low end, where sub enclosures have their own generic delays: Sealed is the best, 6th bandpass - worst. Typical delay of a vented port box - 20-30ms - just to mention one. TA left/right channels might not feet 100% with the subwoofer, so it is a compromise, as always.


Folks will say TA in bass region isn't very important, and phase is everything. I dissagree.. I believe doing this little exercise did something quite special in the bass region. I guess "coherence" is the best term I can come up with, but a kick drum is awesome. It's not bloated or undefined. I should clarify in-phase AND time-aligned = very cool!

Can't wait to do this with the two IB12AU's. 

Strangely though, I couldn't do much at all about that 50hz and below so do I assume that's modal and un-fixable or rather group delay related with the sub itself?


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## Hanatsu (Nov 9, 2010)

T/A is phase shift...

Linear phase shift vs freq 

But you're right, delay in LF IS important


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## Babs (Jul 6, 2007)

brumledb said:


> This is the best I have been able to achieve. But as you can see my sub is 20+ ms out and I am out of delay on my tweeters. The Helix only goes to 15.6ms. So any suggestions on what I should try?
> Right now I using LR 24's for all crossovers. Should I try using a lower order crossover and maybe Bessel or Butterworth instead of LR?
> 
> 
> ...





Hanatsu said:


> Acoustic crossovers are what matters, see the crossovers in your DSP as response shaping. There seem to be sub/mid integration issues as well as T/A and/or L/R FR inconsistancies. I would do individual measurements on all driver by RTA/noise so you get as much averaging as possible. Then compare all the individual measurements to a full left side+sub and a full right side +sub, check if all drivers sum at crossovers. Check actual slopes. Do a sweep of left side and one of the right side in RoomEQ for example, check excess group delay for large peaks which indicates destructive interference.
> 
> If the L/R EQ is set correctly you should be able to set T/A by ear very easy with correlated pink noise. I can measure my car tomorrow and show you why some of these issues occur.
> 
> ...





brumledb said:


> Ok, sounds like I just need to start back at step one. I want to change my house curve anyways. I will go back and make sure I have everything dialed with with EQ before trying to utilize TDA.


brumledb, How'd this work out? You mention "back to formula".. Definitely I'd agree individual driver plots to assess "balance", and I'd encourage don't be afraid to split up your crossover points in the Helix between left/right sides if need be. My mid low-pass's are 1734 and 2244hz for example. Strikingly different electrical xo points, but they match acoustically. Two goals.. 1. Have their up-slopes and downslopes matching. 2. Individual driver EQ and levels matching between left/right sides. You want left and right individual plots approaching the impossible, being both looking like one line on top of each other.

 Let's see the success!


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## Babs (Jul 6, 2007)

brumledb said:


> This is the best I have been able to achieve. But as you can see my sub is 20+ ms out and I am out of delay on my tweeters. The Helix only goes to 15.6ms. So any suggestions on what I should try?
> Right now I using LR 24's for all crossovers. Should I try using a lower order crossover and maybe Bessel or Butterworth instead of LR?
> 
> 
> ...





Hanatsu said:


> Acoustic crossovers are what matters, see the crossovers in your DSP as response shaping. There seem to be sub/mid integration issues as well as T/A and/or L/R FR inconsistancies. I would do individual measurements on all driver by RTA/noise so you get as much averaging as possible. Then compare all the individual measurements to a full left side+sub and a full right side +sub, check if all drivers sum at crossovers. Check actual slopes. Do a sweep of left side and one of the right side in RoomEQ for example, check excess group delay for large peaks which indicates destructive interference.
> 
> If the L/R EQ is set correctly you should be able to set T/A by ear very easy with correlated pink noise. I can measure my car tomorrow and show you why some of these issues occur.
> 
> ...





brumledb said:


> Ok, sounds like I just need to start back at step one. I want to change my house curve anyways. I will go back and make sure I have everything dialed with with EQ before trying to utilize TDA.


brumledb, How'd this work out? You mention "back to formula".. Definitely I'd agree individual driver plots to assess "balance", and I'd encourage don't be afraid to split up your crossover points in the Helix between left/right sides if need be. My mid low-pass's are 1734 and 2244hz for example. Strikingly different electrical xo points, but they match acoustically. Two goals.. 1. Have their up-slopes and downslopes matching. 2. Individual driver EQ and levels matching between left/right sides. You want left and right individual plots approaching the impossible, being both looking like one line on top of each other. Looks like most of your issues is in the region of those 10F's. Mute the sub and forget about it for a while, until you make the scans and GZ front-stage line up like little ducks. 

Caveat.. I really barely know enough about this to be a danger to myself and everyone around me. LOL!

 Let's see the success!


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## brumledb (Feb 2, 2015)

Unfortunately I haven't had time to do any tuning since posting that. Mainly because I can't tune a little at a time, usually when I start I spend hours on it. I did do a little by ear just to get the stage centered. It doesn't sound horrible right now. The bass has a good impact up-front. 
About the cross-overs, until recently I thought just set it and forget it with LR4. I didn't consider that different slopes or roll-off points should be used to electrically alter the speakers response to acoustically match whatever cross-over slope you want to attain. I have been doing a good amount of reading about cross-overs lately so now I understand this a lot better. I should be able to get some tuning in later this week, so hopefully I'll have some new and better graphs to post.


Sent from my iPhone using Tapatalk


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## Babs (Jul 6, 2007)

brumledb said:


> Unfortunately I haven't had time to do any tuning since posting that. Mainly because I can't tune a little at a time, usually when I start I spend hours on it. I did do a little by ear just to get the stage centered. It doesn't sound horrible right now. The bass has a good impact up-front.
> About the cross-overs, until recently I thought just set it and forget it with LR4. I didn't consider that different slopes or roll-off points should be used to electrically alter the speakers response to acoustically match whatever cross-over slope you want to attain. I have been doing a good amount of reading about cross-overs lately so now I understand this a lot better. I should be able to get some tuning in later this week, so hopefully I'll have some new and better graphs to post.
> 
> 
> Sent from my iPhone using Tapatalk



First thing I'd do is forget everything else and just do individual plots on your mids and make those corrections to get their individual plots looking more identical in REW. Then go at TDA again with their timing in mind and an idea of their distance differences.


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## Alextaastrup (Apr 12, 2014)

After adjusting L/R separatelly i tried to make a combined test with both channels playing. And got some nulls and cancellations. So it became nesessary to make further improvements. It should work for you also with the help of TDA.


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## brumledb (Feb 2, 2015)

Babs said:


> First thing I'd do is forget everything else and just do individual plots on your mids and make those corrections to get their individual plots looking more identical in REW. Then go at TDA again with their timing in mind and an idea of their distance differences.


Yeah, I am starting back at square one. I am going to focus on making sure I have everything dialed in with REW before trying to utilize TDA again. 

I'll probably post over in the REW dump thread once I get to work on it. Try to get some opinions and make sure everything is copacetic before proceeding further. I may be going to the big SQ show at College Station in June, so I have to get a good tune in, lest I be embarrassed to demo my truck.

And my new Cross Spectrum UMIK just arrived, time to get to tuning!


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## strohw (Jan 27, 2016)

I'll have to check a full system rta when I get a chance. Usually, I can get 1.5k-20k for both channels to overlap with very nice accuracy. But after I go through and balance for center imaging stuff doesn't look so nice anymore. I'm curious how they're combining overall. I hate not having a peq for the mids though.


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## Alextaastrup (Apr 12, 2014)

A new version of TDA no.11 came out from the Raimonds's table. Now it can also show phase graphs.


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## Hanatsu (Nov 9, 2010)

I'll try the new version out later 


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## Alextaastrup (Apr 12, 2014)

If one has a capacity limit in TA, what is the best solution? MiniDSP? Others?

I am looking for DSP or simply cheap time machine with more than 20ms.

Has anybody tried to ask Raimonds about limitation in the APL1 soft (less than 5ms)? Is it possible to increase this figure or not? Are there any soft upgrade for the APL with better TA possibilities?


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## Hanatsu (Nov 9, 2010)

Alextaastrup said:


> If one has a capacity limit in TA, what is the best solution? MiniDSP? Others?
> 
> I am looking for DSP or simply cheap time machine with more than 20ms.
> 
> Has anybody tried to ask Raimonds about limitation in the APL1 soft (less than 5ms)? Is it possible to increase this figure or not? Are there any soft upgrade for the APL with better TA possibilities?



MiniDSP 2x4 with rear center plugin can do 27ms. It has other limitations though. DCX2496 can do like 1000ms lol.

The 5ms is an offset of the IR wave, should be possible to offset more... I'll send him a mail later.


Sent from my iPhone 6 using Tapatalk.


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## subterFUSE (Sep 21, 2009)

Alextaastrup said:


> If one has a capacity limit in TA, what is the best solution? MiniDSP? Others?
> 
> I am looking for DSP or simply cheap time machine with more than 20ms.
> 
> Has anybody tried to ask Raimonds about limitation in the APL1 soft (less than 5ms)? Is it possible to increase this figure or not? Are there any soft upgrade for the APL with better TA possibilities?


One option to get more delay is to route the output of a DSP channel into an input and then route that input to another output. You could then use the delay on both DSP channels to cascade up to 30 ms on a Helix DSP Pro.

Only downside is this must be done analog.


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## Babs (Jul 6, 2007)

brumledb said:


> Yeah, I am starting back at square one. I am going to focus on making sure I have everything dialed in with REW before trying to utilize TDA again.
> 
> I'll probably post over in the REW dump thread once I get to work on it. Try to get some opinions and make sure everything is copacetic before proceeding further. I may be going to the big SQ show at College Station in June, so I have to get a good tune in, lest I be embarrassed to demo my truck.
> 
> And my new Cross Spectrum UMIK just arrived, time to get to tuning!


Your gonna have fun with the UMIK-1. I suggest trying the method I sent you in the youtube vids for quick measurements in RTA, comparing sides, setting levels and knocking down peaks to get the drivers looking like each other. I know folks are advocates for sweeps for accuracy, so to each his own. RTA averaging in REW is quick and ugly and kinda gets it down at about 1/12 smoothing. 

One way I've done it is to measure one side (side 1), go after the nasties with EQ to get a good looking response, save the plot, go to the other side 2, repeat, save, and compare to side 1. I might go back/forth between them a couple times with end goal in mind of a good plot and matching plots. I find if I distance myself from trying to reach any "curve" at this point it works better.. By working on curve stuff afterwards when multiple drivers are playing (sides, pairs, groups), AFTER TA and centering of course. 



brumledb said:


> Looking good. I would be curious to see how your sub delay would change by using a 2nd order butterworth.


Interesting result here.. I switched to butterworth and had to back off on delay then flip the sub 180 to phase in. Without researching the difference in butterworth vs LR filters, I assume it's the nature of difference between them, but it dialed in nicely.

All said, I have to refrain from having more tuning fun and force myself to tear it down.. Pillars for the 3-way and an IB wall to do.  So I can really boogie in the door mids when they no longer have to pull midrange duty above 400ish.


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## Babs (Jul 6, 2007)

subterFUSE said:


> One option to get more delay is to route the output of a DSP channel into an input and then route that input to another output. You could then use the delay on both DSP channels to cascade up to 30 ms on a Helix DSP Pro.
> 
> Only downside is this must be done analog.





Alextaastrup said:


> If one has a capacity limit in TA, what is the best solution? MiniDSP? Others?
> 
> I am looking for DSP or simply cheap time machine with more than 20ms.
> 
> Has anybody tried to ask Raimonds about limitation in the APL1 soft (less than 5ms)? Is it possible to increase this figure or not? Are there any soft upgrade for the APL with better TA possibilities?


Is the APL1 JUST EQ, or does it also do TA and/or phase? It's kinda vague from memory looking at them.


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## Alextaastrup (Apr 12, 2014)

APL solves minimum phase problems and by this optimizes the time alignment. To a certain degree of cause, as there are many other problems in a car cabin. This will be done automatically by EQ the system. Subwoofer delay partially can also be closer to the front (max 5ms), but this has to be done manually while uploading FIR filters to the unit.


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## thebookfreak58 (Jun 18, 2012)

Any help interpreting the results?

Full system.

Sub: 20Hz/6 - 80Hz/24
Midbass: 63Hz/24 - 250Hz/24
Midrange: 250Hz/24-6000Hz/24
Tweets: 6000Hz/24

All drivers have been individually EQd using REW to a target response. No TA set.


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## Hanatsu (Nov 9, 2010)

Set T/A using distance to drivers first off otherwise it will look like that. When you have done that then we can start to interpret it...


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## Babs (Jul 6, 2007)

Question. Using TDA will dial in both drivers to the business end point of a measuring mic. Brilliant thing. However, should you want to steer center a tad more left than the acoustic center between drivers which is rather right-sided in my car, is it safe to assume that'll completely screw up your TDA plot? So in that case, TDA will help you find dead center timing, then you're on your own if you're tuning to a more frontal center for stage depth perception. 


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## Hanatsu (Nov 9, 2010)

If you don't want it right, you're on your own 


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## Babs (Jul 6, 2007)

Hanatsu said:


> If you don't want it right, you're on your own
> 
> 
> Sent from my iPhone 6 using Tapatalk.



Well actually properly timed its kind of "right" meaning center is perceived as intersecting between midpoint between drivers, geometrically speaking. If that makes sense. So there's a fine line of staying with that and some point left of that so not too far left to compress left stage and stretch right stage. A matter of a couple inches if looking at the rather long dash.


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## Babs (Jul 6, 2007)

That does broach the question of rather "tricking" the results with mic placement. Hmm. According to tracerite, to steer to the left, you subtract delay on left, add delay on right, this bringing the theoretical left driver closer, right driver further away. So, if you positioned the mic for TDA slightly more to the left, this might simulate the same result, no? 

Might be worth some fun for center steering experiment. I guess we're taking splitting hairs here. But hypothesis being that when your noggin is listening in same 0-point position after -2" TDA mic position (left), the result would be a slightly more left center image at your ears, still well timed. So, If you move your head an inch or so left, so ears center where the mic was at TDA measurement, it'd be exactly timed and ITD stage (dunno if that's proper term but I'll go with it) should then move rightward. ?? 

Not counting leveling adjustments of course, since image is ITD and ILD driven (and I'm only beginning to understand those so I know I'm no expert nor claim to be one or even play one on TV). 


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## claydo (Oct 1, 2012)

Hey scott, one thing to keep in mind about nailing t/a, are the advantages to stage reproduction as far as depth, perceived ambience and such. Not only are you working for a proper center, you're building the stage and the phase adjustments make sure all the geometry is kept in order when listening. I mean, I can center my stage with t/a....... and levels. You can have yer levels just right, and center well, but the overall stage representation can be funky from t/a errors.......on the other hand, you can have your t/a dialed and still skew yer stage with levels and eq. To add to the top of this complicated stage construction, you can have your t/a and levels dialed, then funk up the phase with eq, requiring t/a adjustment, which can in turn funk up your tonality.......lmao, this whole hobby can be maddening, but it is a serious challenge, and no car is perfect, they just have different disadvantages. The key is making the right compromises to satisfy your ears........


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## Hanatsu (Nov 9, 2010)

Moving the mic to the left would simulate more required delay to left side. More delay on left channel moves stage to the right. I think you need to place mic to the right. Then there would be less delay on left channel and stage would move to the left.

Hate thinking backwards, I might got it wrong...


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## thebookfreak58 (Jun 18, 2012)

Hanatsu said:


> Set T/A using distance to drivers first off otherwise it will look like that. When you have done that then we can start to interpret it...
> 
> 
> Sent from my iPhone 6 using Tapatalk.


As requested.

Times set using the trace rite website. I set the midbass/sub delay using the 'cross over' method?

Values:
RTW: 1.77ms
LTW: 0.53ms
RMR: 1.55ms
LMR: 0.39ms
RMB: 6.51ms
LMB: 4.41ms
Sub: 10.02ms 180deg phase shift


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## Alextaastrup (Apr 12, 2014)

The idea of null-delay in the low end has resulted into new set of measurements and XO/TA settings. 

Initial info: sedan, 3way passive, sub almost without EQ possibilites (only from HU), APL1 - only for the front channels.

After some attempts I came to the following results - see attached graphs. Tests were made both in TDA and REW in the same single point at the driver's headrest (no averaging). Therefore - information above 1 kHz is not so interested here. My intention was to minimize delay of the sub when connected to the front by different sets of XO and TA settings. The best was achieved by implementing the TA difference between the left and right channel of 51cm, while actual difference from the listening position is only 27cm??? When applying the settings close to 27cm, the closest channel is dominating, moving the scene to the left. Remind, I do not have possibilities to adjust the volume for a separate speaker.

All these three pictures show 2 channels +sub playing simultaniously.

DFR shows less than 1 ms above 500Hz and around 2ms from 40Hz!!! until 500Hz. I suppose that below this we can see nonlinear things based on the mechanical construction of the subwoofer speaker and its work in a sealed box. Correct me if I am wrong on this statement.

What is interesting, that the REW mesurements showed a significant GD (appr. 60ms), while dfr (TDA) has not revealed this. On the other hand, we can observe some energy (delayed in time domain for the same value) on the 2D graph.

Impressions - as there is no many sounds below 40Hz in music, compared to other frequencies, this might be expected some audible improvement of the sound at the LF. And that is correct: sound is more tight, clear and straight forward. 

Present XO points (due to the lack of TA capacity - used everything possible in HU/H100 -336cm): 50Hz, 6dB/oct - sub, 63Hz, 12dB/oct - mid.

Comments are very appreciated.


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## sqnut (Dec 24, 2009)

Put your sub on like a 6th order slope and the mid on a 4th order and measure again. See if there's a difference between 50-500 hz.


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## Hanatsu (Nov 9, 2010)

Group delay and DFR/TDA plots don't display the same thing. I don't know exactly what the difference is... TDA is something else and just like APL can't be compared to anything else I've seen.

I will post a detailed guide how to utilize TDA and how to set T/A properly. Idk, tape measure distance doesn't seem to work very well for a lot of people.


Sent from my iPhone 6 using Tapatalk.


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## Elgrosso (Jun 15, 2013)

Guys, is there a significant delay difference in using an analog or digital chain?

I mean, for simplicity and practical reasons I never used the exact same setup for measurements and listening, it was:
Phone > digit > dac > analog > apl > analog > ms8 (listening)
---------------- Laptop > analog > apl > analog > ms8 (measurements)
The difference was only the dac delay (if any)

But now the plan is to use full digital to the C-dsp:
Phone > digit > airport express and/or icon ido > digit > apl > digit > cdsp
------------------------------------------------- laptop > analog > apl > digit > cdsp

So bigger difference in chain, might have more impact, should I bother about that?


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## Alextaastrup (Apr 12, 2014)

sqnut said:


> Put your sub on like a 6th order slope and the mid on a 4th order and measure again. See if there's a difference between 50-500 hz.


I have tried almost all possible combinations due to certain limitations in the present install: TA: 0-336cm - not too much for a sub in a trunk (sound is comming through two old holes in the backshelf).

Filter order: 0-4 (max 24dB/oct).

When the sub polarity (electrical) was turned to 180 degrees, the best match in phase was even more strange: LPF:40Hz, 1.order, HPF: 80Hz, 1.order. Now the sub is back to 0 degrees and therefore - another set of XO points. I need more capacity in TA. Will buy soon miniDSP for this purpose. Just to use as a time machine.

EQ of sub is also not really possible as I have only 2 frequencies in the 5 band PEQ (63 and 125Hz). Maybe another miniDSP will be needed.

Another question is about placement of the mic during delay measurements. I am not sure that during the last set of the tests, the mic was placed exactly at the same point as during the previous one. At that time I have concentrated in the area 100-20000Hz and have managed to find a set of parameters which gave me less than 1,5 ms in all this diapason. But now - after some readings, were authors stated that 1,5-2 cycles (periods) are just fine and are below the threshold for mid and high frequencies. So I was trying to make the LF range as flat as possible for group delay -by rather limited sources. Result: 2,5ms until 40Hz - is it audible?


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## Hanatsu (Nov 9, 2010)

All right, I promised I'd give a walkthrough how to setup a full system. The tape measure method isn't always accurate but can be used as a baseline to start from. There are many methods out there and people swear their method is superior...

This is what I find to be the optimal/easiest way of doing it, I ignore the difference between drivers on the same side to begin with. This is a combined "by ear"/measurement method. 


1. First step is to make sure the left and right sides got an equal frequency response, *this is paramount, if L/R differs more than 3dB the entire procedure will fail.* If you use APL, the software automatically fixes the L/R balance. If you got a normal DSP you need to set it up manually with RoomEQ software or such.

2. *Download this*: Test Tracks. We're interested in the first track, this is correlated pink noise (mono recording).

3. In your DSP mute all speakers except midbass drivers, keep both drivers on (left and right).

4. Now we need to determine the acoustic center, if you unsure where this is, it's usually slightly left of the physical center of the dash in most cars. Put a piece of tape there or something else to mark this place.

5. Play the correlated pink noise though both speakers (left/right), delay driver side until you hear the noise coming from the tape marker on dash.

6. Now mute midbass drivers and turn on both midrange drivers (in a 3-way). Repeat step 5.

7. Mute midrange drivers, turn on both tweeters. Repeat step 5.

8. Now all drivers are tuned to the acoustic center. Turn on all speakers + sub. Run TDA, place mic in the middle and about 6 inch in front of the headrest. Don't sit in the seat, it's ok to be in the back seat though.

9. Now we should have something to work with, all areas where the speakers don't overlap should be flat (a black straight line). What we want to look for is offsets and other discrepancies around the crossover of the drivers. This means that the speakers are misaligned to each other by some amount. 

_*** The tweeter crossover is usually place high in frequency, the wavelengths will be small and therefore a very small delay shift is required to bring them back in phase around the crossover. The lower in frequency we go the bigger delay is needed for a given phase shift. There are multiple way of lining up speakers to eachother within a channel, I believe the "magnitude summing method" is easiest but I don't wanna bring this channel off topic***_

10. Now that we already set L/R coherency and just want to set the delay within a channel (the delays between all left OR right speakers), it's important that we don't change the L/R relation delay numbers, we only want to offset it. *Write down the actual delay between midbass drivers, between midrange drivers, between tweeters.* This number might be offset, but not changed. 

In other words left midrange might have 1,5ms delay and right midrange 0ms delay. If you set 2ms delay on left and 0,5 on right, there is still 1,5ms delay between these two drivers and the center will not shift. This is what I refer to as an offset. 



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


1. After running the sweep in TDA. It might look something this now;



Here we see that midranges are slightly delayed vs tweeters and the midbass is about 6ms away from midranges. DFR will show the numbers with precision. In this situation we want to delay midranges 6ms and tweeters 6,5ms.

2. Enter numbers + the relative delay between L/R in your DSP and do another sweep.



Should look something like this now. The shift at 50Hz are due to subwoofer group delay, that is a whole other topic...

3. Done!


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## Hanatsu (Nov 9, 2010)

This is how my L/R balance looked before any response shaping. It needs to be this close.


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## Babs (Jul 6, 2007)

Awesome write up Hanatsu! 


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## Elgrosso (Jun 15, 2013)

Thank you Hanatsu!
So you used the APL before TDA, will you re measure/apply new EQ eventually after again?


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## Elgrosso (Jun 15, 2013)

Rhhaaa demo expired! :/


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## brumledb (Feb 2, 2015)

Elgrosso said:


> Rhhaaa demo expired! :/




Yeah mine did too. I was pretty bummed. I even tried uninstalling, re-downloading, and reinstalling but it still recognizes my computer and says demo expired.


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## LumbermanSVO (Nov 11, 2009)

I played with TDA and my car a bit today. I was able to get this:










My system isn't complete yet, I'm missing midbass drivers. At the moment the crossover between my mids and subs is 200hz @48db. Once I have the midbass drivers in I'll only take the mids down to the 350-450 area. The horn to mid crossover at 1200hz @48db.


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## Alextaastrup (Apr 12, 2014)

brumledb said:


> Yeah mine did too. I was pretty bummed. I even tried uninstalling, re-downloading, and reinstalling but it still recognizes my computer and says demo expired.


TDA is exceptional tool and it worth buying. Besides it is all the time Boeing upgraded and you might be able to use the same license for different program modifications.


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## Elgrosso (Jun 15, 2013)

TDA is awesome


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## Babs (Jul 6, 2007)

Alextaastrup said:


> TDA is exceptional tool and it worth buying. Besides it is all the time Boeing upgraded and you might be able to use the same license for different program modifications.



Worth buying for how much? Saw the pricing in pounds and got frightened and left. Hehe. Is there a Diyma student diy'er discount?


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## Hanatsu (Nov 9, 2010)

Elgrosso said:


> TDA is awesome


Lol, what happened to the graph window? xD

Looks good (great actually...) otherwise!


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## Elgrosso (Jun 15, 2013)

That's // desktop on mac through teamviewer, gets funky sometime


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## Alextaastrup (Apr 12, 2014)

Babs said:


> Worth buying for how much? Saw the pricing in pounds and got frightened and left. Hehe. Is there a Diyma student diy'er discount?


Yeah, savings will be forgotten soon, but this program will serve you a long time ahead. 

One of the advantages is you could run both front sides together and to see how they play simultaniously. For doing this one should select "mono" as the output signal. This feature had helped me to optimize the TA settings in order to avoid mutual cancelling by respective drivers.

Another "phat" feature - final table with the data measured, which might be derived from the graphs.

Most probably other consumers will find something else, which will be interesting in this soft, as distortion levels, delay FR, 3D presentation of the test results etc.

Recently I have used the TDA to check how the APL makes time alignment. With the purpose I have delayed one of the front channels by 15ms (need more actually in order to connect the front to the subwoofer). Single test with both fronts running has proved that delay made by APL is quite accurate and corresponds to the desired value. 

My next little project with the TDA will be determination of the car transfer function, for which I intend to use AFR function. Interesting to exchange some experience with those who tried it before. APL Worshop could be the alternative solution for this, maybe little bit more complicated, but also more precise. 

What do you think guys?


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## Alextaastrup (Apr 12, 2014)

Elgrosso said:


> TDA is awesome


Great curve! What is the scale range on the X-axis?

I was not able to get so clean response with my passive front and the subwoofer playing from the trunk through two 17cm holes in the back shelf (sedan). It means that the whole trunk plays as a ported enclosure with uncontrolled ports, similar to unpredicted bandpass.


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## Elgrosso (Jun 15, 2013)

Alextaastrup said:


> My next little project with the TDA will be determination of the car transfer function, for which I intend to use AFR function. Interesting to exchange some experience with those who tried it before. APL Worshop could be the alternative solution for this, maybe little bit more complicated, but also more precise.
> 
> What do you think guys?


I suspect APL would be the right tool there no? Since you'll need many many many points. Or what else did you have in mind?





Alextaastrup said:


> Great curve! What is the scale range on the X-axis?
> 
> I was not able to get so clean response with my passive front and the subwoofer playing from the trunk through two 17cm holes in the back shelf (sedan). It means that the whole trunk plays as a ported enclosure with uncontrolled ports, similar to unpredicted bandpass.


Probably the default 30ms.
I usually start with 30, then go to 10ms, with sometime -1 as a reference.
This was left or both I don't remember. Left is always easy to get clean, right not so.
For sub and woofer I actually quite like the ease of use (biggest marge of errors on ms), but for midranges and tweeters I have hard time to not mess everything up!


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## Raimonds (Jun 13, 2014)

Babs said:


> Worth buying for how much? Saw the pricing in pounds and got frightened and left. Hehe. Is there a Diyma student diy'er discount?


Ok Babs and other TDA fans - *5 copies of TDA software for student`s price* is available now.


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## brumledb (Feb 2, 2015)

Raimonds said:


> Ok Babs and other TDA fans - *5 copies of TDA software for student`s price* is available now.




Email sent. I would like to purchase one.


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## Babs (Jul 6, 2007)

Raimonds said:


> Ok Babs and other TDA fans - *5 copies of TDA software for student`s price* is available now.


Very nice.. PM sent Sir


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## Elgrosso (Jun 15, 2013)

Cool! The more the merrier!


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## piyush7243 (Sep 9, 2009)

PM sent

Sent from my Nexus 6P using Tapatalk


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## dgage (Oct 1, 2013)

What is the difference between the APL TDA and APL Workshop software? Thanks.

EDIT - Nevermind, found my answer.
http://www.diymobileaudio.com/forum/2606098-post85.html


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## Alextaastrup (Apr 12, 2014)

dgage said:


> What is the difference between the APL TDA and APL Workshop software? Thanks.
> 
> EDIT - Nevermind, found my answer.
> http://www.diymobileaudio.com/forum/2606098-post85.html


Right. Workshop can not give you a picture in a time domain. But stabillity of APFR results is simply impressive. On the contrary , TDA will present the system response to the sweep signal in only one point (typically - listening position). TDA gives a possibility to see both channels and sub playing simultaniously.

Both are great measurement tools, but you need also a measure to make delays. In this case DSP's which are available on the market (for the car application) are limited to 10-21ms. This might be not enough for a complicated sub enclosure, placement of a subwoofer in the trunk, etc.

By using additional program from Acoustic Power Lab, called ConeqC1 it is possible to make a delay from 0 till 4,979ms as many time as you wish. Just browse to find necessary FIR filter on your PC, chose required time delay and save it as a backup. Next time - use this as a new FIR filter and so on.


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## claydo (Oct 1, 2012)

Ooooh, pm sent!

Hope I'm not too late!


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## Elgrosso (Jun 15, 2013)

Alextaastrup said:


> By using additional program from Acoustic Power Lab, called ConeqC1 it is possible to make a delay from 0 till 4,979ms as many time as you wish. Just browse to find necessary FIR filter on your PC, chose required time delay and save it as a backup. Next time - use this as a new FIR filter and so on.


Wow I need to try that, I still didn't play with C1 yet! (So many things to do...)
So you add delay to the APL filters?


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## Alextaastrup (Apr 12, 2014)

Exactly. And checked this wirh TDA. IIt works.

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## Alextaastrup (Apr 12, 2014)

Do we need to have nul as a main goal when making TA?

Head movements are around 5cm during driving. There is also a limit for threshold at different frequencies. Are these things audible below let say 5msec? Used almost 3 hours yesterday trying to press delays down to nul. Managed about 3,5msec (incl. subwoofer in the trunk), 0,3msec above 600Hz. Your opinions, please?

Frequency (Hz)*	Threshold (ms)*	Threshold in T*
(periods or cycles)
8k Hz*	2 ms*	16 T
4k Hz*	1.5 ms*	6 T
2k Hz*	1 ms*	2 T
1k Hz*	2 ms*	2 T
500 Hz*	3.2 ms*	1.6 T


Are there any info about threshold values below 500Hz?


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## Hanatsu (Nov 9, 2010)

I made a lengthy post about it somewhere, lemme see if I can find it.


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## Alextaastrup (Apr 12, 2014)

I think I have read it, but can not remember figures below 200Hz.









Results of my last TA tuning - front should be first delayed by appr. 45 msec before I could make fine-tuning.


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## Elgrosso (Jun 15, 2013)

Alextaastrup said:


> I think I have read it, but can not remember figures below 200Hz.
> 
> View attachment 135417
> 
> ...


Seems very nice, sub and woofers are within 1ms or so no? Why did you say 3.5ms?
Did you adjust all this with C1? (If I remember you have a passive 3 way)

For the threshold around 20hz I read about 30ms is acceptable, some says much more.
I don't know what to think of this, since I can clearly hear smaller differences there.
But I now have two subs (front and rear) so it's maybe more the different summing that I hear, or something else (eq?).

About the head movement/placement, did you try TDA in different points?
I may try, just like left ear/right ear to compare to the centered point, to see the difference before I optimize it "too much".


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## Alextaastrup (Apr 12, 2014)

Yes. Tried left-right. But was more interested in moving the mic up-down. Lower position of the mic. makes the difference between the woofers and mids less. But again my height coud not be changed as the placement of woofers in the front doors. Not in this install at least. So I have to live with it.

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## Elgrosso (Jun 15, 2013)

Alextaastrup said:


> Yes. Tried left-right. But was more interested in moving the mic up-down. Lower position of the mic. makes the difference between the woofers and mids less. But again my height coud not be changed as the placement of woofers in the front doors. Not in this install at least. So I have to live with it.
> 
> Sendt fra min GT-I9505 med Tapatalk


Less when you lower it? in mine it's the inverse, the dash mask mid/tweeters.
Just gave me the idea to try a bottom limit to the mic movements during APL "painting".


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## Hanatsu (Nov 9, 2010)

Alextaastrup said:


> I think I have read it, but can not remember figures below 200Hz.
> 
> View attachment 135417
> 
> ...


http://www.diymobileaudio.com/forum/3565890-post19.html


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## Alextaastrup (Apr 12, 2014)

Thanks a lot

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## Raimonds (Jun 13, 2014)

Dear Friends,

Please take a look on Jack Regula`s paper:
https://soundforums.net/forum/pro-a...oking-at-speakers-and-rooms-review-of-apl-tda

And 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.
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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.


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## Alextaastrup (Apr 12, 2014)

Great article.

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## oliverlim (Dec 5, 2016)

With regards to the method of using TDA. Since it is measuring frequency arrival times, why do we need to ensure that both L and R frequency response should be close or within 3db? A higher or lower vol does not change each frequency arrival time right?

I asked, as I am still testing if APL1 would be worth investing. I have purchased the softwares including the VST for use in my home office system. 

So if L/R frequency balance is important, I would have no way to see if TDA can make any further improvements in my car system or see if I can use TDA to improve on my cars delay timing?


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## Alextaastrup (Apr 12, 2014)

Without TDA you are just on the halvway towards a good sound in your car. It might be less important in your office as distance to L/R loudspeakers normally is the same. 

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## oliverlim (Dec 5, 2016)

Can any one help me analyse what my TA should be base on these measurements? 

I have a 3 way active without subs. Crossovers at 250/3500 L-R 24

My mids are the furthest away from me base on measurements. Measurements seem to say that my underseat woofers are further away then my mids or tweeter so they should instead be put as Zero delay and around 3-5ms delay can be added to my mids and tweeters ?


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## sqnut (Dec 24, 2009)

Set everything based on physical distances and then do your measurements. Don't try and out think the poor tape measure .


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## oliverlim (Dec 5, 2016)

sqnut said:


> Set everything based on physical distances and then do your measurements. Don't try and out think the poor tape measure .


My measurements above are base on TA with my
Tape. Does seem like it could be improved


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## Raimonds (Jun 13, 2014)

oliverlim said:


> Can any one help me analyse what my TA should be base on these measurements?
> 
> I have a 3 way active without subs. Crossovers at 250/3500 L-R 24
> 
> My mids are the furthest away from me base on measurements. Measurements seem to say that my underseat woofers are further away then my mids or tweeter so they should instead be put as Zero delay and around 3-5ms delay can be added to my mids and tweeters ?


Right channel has discontinuity of delay at 3.5kHz. 
A 0.7 ms delay (2.5 cycles of 3.5kHz) for tweeter should be good.
Crossover points at 250 Hz are ok.
You should observe 3 curves - TDA, AFR FFTq and GDR with "subtract minimum phase" ON for final decision.


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## Babs (Jul 6, 2007)

Raimonds said:


> Right channel has discontinuity of delay at 3.5kHz.
> A 0.7 ms delay (2.5 cycles of 3.5kHz) for tweeter should be good.
> Crossover points at 250 Hz are ok.
> You should observe 3 curves - TDA, AFR FFTq and GDR with "subtract minimum phase" ON for final decision.


That's good stuff.. I need to crack out TDA and try it again once my system is in again ready for a retune. From memory, it was quite the iterative process when I did it, trial and error. You could really tell when it aligned up the 3D plot suddenly looked lovely, smooth and lined up on the left.


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## oliverlim (Dec 5, 2016)

Very Strange. I was sure i saw Raimonds and some other replies yesterday. But they seem to have disappeared? Raimonds was saying my Right Tweeter was 0.7ms off? Cant find it anymore.

Anyway I made that adjustment and tried to bring the understead woofer closer to zero. But now it seems like things are a little more messed up. It could be my mic measuring position is a little off. I now have saved the seat position in a memory. The left right should be correct. But the up and down or forward and back may be a little different then the first measurement. This new position however, is the correct position.

I am still a little unsure how to read the charts to make the appropriate adjustments. Seems like my tweeters are a little ahead of my mids which is a little ahead of my woofers.


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## Babs (Jul 6, 2007)

oliverlim said:


> Very Strange. I was sure i saw Raimonds and some other replies yesterday. But they seem to have disappeared? Raimonds was saying my Right Tweeter was 0.7ms off? Cant find it anymore.
> 
> Anyway I made that adjustment and tried to bring the understead woofer closer to zero. But now it seems like things are a little more messed up. It could be my mic measuring position is a little off. I now have saved the seat position in a memory. The left right should be correct. But the up and down or forward and back may be a little different then the first measurement. This new position however, is the correct position.
> 
> I am still a little unsure how to read the charts to make the appropriate adjustments. Seems like my tweeters are a little ahead of my mids which is a little ahead of my woofers.


Yeah posts are kinda showing up and kinda disappearing.. The site's got bugs and gremlins right now I think after a software upgrade.

Yeah I remember reading Raimond's response and it was a rather largish .7ms or so adjustment recommended.. Delaying out the tweeter to meet the mid. Trick is trial and error getting all those drivers to line up. Keep in mind then, when you're fixing delay times between sides, you'll then need to re-assess and adjust between pairs (left compared to right). 

Theoretically you should be able to nail everything if you adjust left tweet/mid together to right tweet/mid. Helix allows this so easily by grouping drivers in the TA screen so I can move my whole left side over to right without disturbing timing between drivers on the left side tweeter on down.


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## Alextaastrup (Apr 12, 2014)

Yeaa, it is nice feature of Helix. But you can make this very simple with apl-soft by adding time delay to one of the channels. 

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## Alextaastrup (Apr 12, 2014)

For doing this it is possible to delay fir-filter. And more over, you can do it very precisely .

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## captainobvious (Mar 11, 2006)

Interesting software. I'll be playing with this shortly.


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## Babs (Jul 6, 2007)

captainobvious said:


> Interesting software. I'll be playing with this shortly.



How'd it do for you Captain?


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## LumbermanSVO (Nov 11, 2009)

captainobvious said:


> Interesting software. I'll be playing with this shortly.


If you haven't purchased it yet, I have it...


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## subterFUSE (Sep 21, 2009)

LumbermanSVO said:


> If you haven't purchased it yet, I have it...




I have it, too. Never used it yet, though.


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## Babs (Jul 6, 2007)

subterFUSE said:


> I have it, too. Never used it yet, though.
> 
> 
> Sent from my iPad using Tapatalk



Would be an interesting comparison to the pulse track and Smaart IR tools. 


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## Babs (Jul 6, 2007)

Here’s an interpretation question for you guys on TDA... I’ve not listened to this yet but, here’s what I was able to achieve in TDA mainly by a lot of trial and error starting with sides then overall. Very very odd delay setting for right midbass to achieve this. Also very low delay amounts on IB subs. 

Thoughts?

















Edit: So I listened with skepticism that was well founded I suppose. It wasn’t even remotely close, on all fronts. So either I’m just doing something terribly wrong in assessing TDA, or something else. 


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## Raimonds (Jun 13, 2014)

Hi,

You can use such tune if crossover points are pretty much good in terms of AFR - no deep holes, for minimum phase filters (ordinary IIR)
It is absolutely correct if you have linear phase filters.
You are correcting min. phase crossover's GD such way also in your example.

But, if try to be accurate as much as possible you should go to not "flat" as in your example
but to a crossover's group delay curve, for minimum phase filters.
Let's take such crossover:










Its Group delay curve is such:










And its TDA picture:










Then, it is possible to use time correction with such GD:










And get this:



















If summarize, it is semi solution to correct crossover's GD using band's delays
that can be used in some cases with caution, keeping look on AFR.


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## oliverlim (Dec 5, 2016)

I know this thread is rather quiet. But I was hoping for help on getting my time alignment correct using TDA. Please see my measurements for both sides at drivers seat with TA only via tape measurements. 

And then both with extra delay on mid by 10cm and woofer by 20cm as well as reversing phase for mid and woofer to see if it improves. 

My system is a 3 way active with tweeter, mids and woofer. No subs. crossovers at 200 and 2.5k

If I were to check the first measurement, it would seem like the mids are around 1ms slower then the tweeter and the woofers are at least 7ms slower then the mids. So the correct way to adjust for it is to increase the distance/delay on mid by 1ms and woofer by 7ms so that they arrive earlier and in time with the tweeter? 

How do you determine from the graph if say the Right tweeter signals is coming faster then the Left tweeter? Do you run a Left only measurement and see the graph and adjust accordingly?


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## StabMe (Nov 17, 2011)

I am having a similar problem.

Here is the graph i get with TA set by tape measure:





















When add almost 15ms delay to the midbass and tweeter, the graph looks something like this:










It is a Car PC. I am using AudioMulch for processing. Plugin called LS_Filter is used as a crossover. Some PEQ to fight with peaks. ConvolverVST is applying a FIR filter generated by Python based thingy called PORC (Python Open source Room Correction).

I have a huge sub in the trunk of a Range Rover Sport. It is a 21" PA sub. Have Beyma 8G40 in ported enclosures in my doors. And full body horns under the dash.

Delay on the sub is 0, midbass drivers and horns a delayed in the range of 0-2,5ms. So, nothing huge.

Frankly, the system sounds terrific  Imaging is nice, tonality is fantastic, dynamic is from the outer world. Sometimes sub bass sounds like it is lagging a bit. But maybe it is me now trying to rationalize the graph 

Why TDA "thinks?" the sub starts acting 15ms later than the rest of the system?

Why the graph becomes crazier after the "needed" adjustment?

P.S. Measurements are taken with the engine running. Measuring it with engine off gives the same basic picture.


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## Elgrosso (Jun 15, 2013)

This is without any FIR applied right?
Also engine running might not change a lot but I would measure without it just for clarity, it could disturb the reading near 80Hz.

I imagine it’s your ported midbass delay around 100Hz (but that’s really high).
I wouldn't try to get it flat, but just the smoothest possible, even if 20Hz plays 20ms later.


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## StabMe (Nov 17, 2011)

This is with FIR off, right.

100hz is the sub/midbass x-over point. Door enclosure port is tuned to 80Hz.

Engine running adds some info at 40-50Hz, which i could also observe on REW measurements. Sweeps overpower the engine hum by 20-25dB. Will recheck again.


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## Elgrosso (Jun 15, 2013)

Why did you port the beymas, because you like to play sub-less sometimes?
That’s where I would start, plug their holes and see what happens.
They should sound great just in sealed (well they did for me).
Other than that IDK!


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## captainobvious (Mar 11, 2006)

Always measure with the engine off.


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## thehatedguy (May 4, 2007)

Could it be group delay with the ported enclosure?


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## subterFUSE (Sep 21, 2009)

Ported enclosures always have smeared impulse response. You essentially have 2 point sources with them. The front of the cone and the port. The port will be delayed.


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## cycfari (Jan 9, 2009)

Here's my first tune with APL1 & TDA and I am very amazed with the results. Will try to fine tune my crossovers as there are some dips to take care of. any advice will be much appreciated. 

Btw , I am using the MS8 curve for APL1.

My set up is 3 way active :

1. MB - 40hz/24db..600hz/24db
2. Mids - 800hz/24db--3khz/24db
3. Tweeters - 3khz/24db

SPFR with and without APL


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## cycfari (Jan 9, 2009)

AFR with & without APL


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## cycfari (Jan 9, 2009)

DFR with & without APL


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## Hanatsu (Nov 9, 2010)

Update to TDA... there has been a few new releases.

TDA IM
TDA EQ
TDA with simultaneous measurements 

Reviewed the 1st (link down below), I'll get to the other two later.









Measuring intermodulation distortion easily


IMD is a form of non-linear distortion that occurs when two tones are playing at the same time at different frequencies. New tones not present in the signal are presented at multiples of the sum and subtraction of the given give tones. For example 100Hz(f1) + 1000Hz(f2) will produce IMD at...




www.diymobileaudio.com


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## Durgesh (Sep 18, 2014)

Hi
I tried new TdaRt.

Attached passenger side power response measurements (imported into rew & offset to 10db).

Here are two different TDArt measurement sets of the passenger side with different delay settings.

Which one should sound better? Or both are totally wrong?
























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