# Sticky  First-timers guide to measuring your system



## Hanatsu

OK. I've had some requests how to measure your car audio system and how to work with RoomEQ as well as fine-tuning your system for optimal staging and tonality. Rather than explaining it all in private chats I might as well do a quick guide as more people can learn and members can refer to this thread if someone asks questions.

I've previously made threads about RoomEQ available here:

*Measure T/A with RoomEQ*

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/145484-measure-time-delay-t-arta-roomeq.html

*How to use the AutoEQ function in RoomEQ*

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/144455-quick-tip-using-auto-eq-roomeq-rew.html

_But let's start with the basics..._

*What you need:*


*[*]Computer, preferably a laptop

[*]RoomEQ/REW software, available here: RoomEQ BETA DOWNLOAD

[*]Measurement microphone, preferably a calibrated microphone or a microphone that have a supplied calibration file. Both USB microphones and phantom powered microphones that require a preamp are common.

[*]DSP, either built-in in the headunit or preferably a stand-alone unit. Left and Right side equalization is an absolute necessity! 

[*]AUX-in feature of the headunit. In a standalone DSP you can simply use the DSP inputs directly from the soundcard output.*

*BE IN A QUIET PLACE WHILE MEASURING!! ENGINE OFF, ALL WINDOWS, DOORS, TRUNK CLOSED*

_as an alternative you CAN use a CD with uncorrelated pink noise as a "trigger source" together with the RTA function in RoomEQ but I don't recommend this way of measuring since you will attain less data than sine sweeps and you won't be able to use the more advanced features in RoomEQ._

See pictures below how to setup the hardware. Use headunit AUX-in if possible.





Alright. When that's done it's time to configure RoomEQ. This is how RoomEQ looks when you enter the software, begin with clicking on "Preferences".



In preferences, you first setup your Audio input and output. If you got an USB mic, it will show up under input device. IF you got a mic together with a pre-amp you might wanna do a soundcard calibration by connecting the line-in to the headphone jack of the soundcard and hit that "Calibration" button. It's usually not that critical though. 



The next tab in preferences that's important is "Mic/Meter". Here you import the calibration file of the microphone. Some microphones got a "general" calibration based on averages over many microphones, some got individual calibration files for each single microphone... and obviously that's more accurate. A calibration file for the microphone is generally more important than calibration the soundcard. Most microphones tend to get non-linear in the lows and the higher 2 octaves. A calibration file is highly recommended!



Under "House Curve" you can import a target response for usage with RoomEQ's autoEQ function. This step is optional.



*NOW CLOSE PREFERENCES.*

Now you can choose how you want to measure. If you don't have a stand-alone DSP or an AUX-in in your headunit you might need to use a CD with pink noise and use the RTA function highlighted in BLUE in the picture below.

For normal measurements, click "Measure".



This the "Measure" screen:

Start Freq: 20Hz
End Freq: 20000Hz
Length: 256k
Sweeps: Determines the amount of sweeps, these will be automatically averaged. Use 2, it's generally enough.
Level: Set an appropriate level here, don't let the sweep clip (i.e reach 0.0dB while sweeping).



*Now, click "Start Measuring".*

After the measurement is finished you should have a graph on your screen, it should look something like the picture below (it might not look so smooth before any EQ). 



The graph shows level in the Y-axis and frequency in the X-axis, i.e SPL vs Frequency (Frequency Response). 

Below is a zoomed in picture the menu-tab.

*Use "All SPL" to observe the Frequency Response, you can overlay several measurements under this tab as well.

*Set scaling of the graph in "Limits". Highlighted in RED.



--Scaling should be set so you see the graph in 5dB steps, between 20Hz and 20000Hz. You can set it to 20-400Hz if you looking at the subwoofer response for example). I had mine set for 0dB bottom, and 90dB top in the example. 

--In "Controls" the most important feature is "Smoothing". Choose the amount you want and click "Apply to selected". Here's a rule of thumb...

For Subwoofer measurements, use 1/24dB.
For Midbass/Midrange measurements, use 1/12oct
For Tweeter measurements, use 1/6oct or even 1/3oct if you have done few "physical" averages,







I will continue the guide tomorrow, but you should get the basics "HOW TO MEASURE" now... I shall explain where the microphone should be placed, how to use autoEQ, parametric equalization and more in the next posts. Hope you enjoy this.


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## fig32

This is great! Thanks for posting such a detailed tutorial. I have been using REW now for a few weeks, read tons of threads and finally getting my system dialed in, such that I like it. I know this will help a lot of people that are just starting out. 

Looking forward to more!


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## theoldguy

VOTE FOR STICKY!!!!! (yes Im yelling)


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## 1fishman

MUCH THANKS!!!

Any recomendations for a microphone?


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## subterFUSE

STICKY!


My UMIK-1 should be arriving any day now. Your timing with this thread was perfect!


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## cajunner

gggggiggety!


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## Heavensheros

cool read


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## venki7744

Sub'd..and a sure candidate to be Sticky!! Thanks Hanatsu


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## theoldguy

isnt there a "vote for sticky" button somewhere?


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## req

yep... once i get the carPC dialed with windows 8.1 i will have this built into my install


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## Hanatsu

Thanks guys! 

Here's the next part:

*Managing measurements...*

OK. When we measure our system we need to do several measurements to get a complete picture of what's going on. I highly recommend measuring each speaker in the entire system separate (all speakers muted but one). Doing lots of measurements takes some managing of all the graphs, otherwise you get lost in a mess of plots that makes your head spin 

So before going into the basics of equalization we going to continue working with the software to make ourself more familiar with the important features.

Here's a overview over some important functions:



*The list to the left is used to manage and select the current measurement. 

*Change color of the graph if two plots end up having the same color which makes overlays hard to differentiate from each other.

*Name each measurement and use the comment section to manage each graph. _An example how to use naming and comments; Name = Left Midrange // Comment = "Measured 2 inch in front of the left ear"._

*Now let's do a second measurement (right driver in the example below).*



*The second measurement will end up directly below the first one in the list to the left. Name it appropriately. IMPORTANT! ( Avoid creating a mess...  )

*At the bottom of the graph, there's now two boxes which you can check and uncheck. This hides or shows the different measurements in the "All SPL" tab.

*Choose the appropriate smoothing for easier viewing. Smoothing a plot is not permanent and does not result in loss of data, you can "unsmooth" it at any time. 

*Now to another very important feature. "Averaging".*

(Note how the graph got easier to view as I applied smoothing to the measurements.)



_Facts: When you measure a speaker in the car, the frequency response will change as you move the microphone a little. The effect is minor in the lower frequencies, in the "modal range" but gets worse as the wavelengths get smaller, i.e higher frequencies. The higher frequency you measure, the more reason to do "physical averaging", i.e moving the mic and perform several measurements on the same speaker. We do not sit stationary in one exact spot, that's why we need to consider this. _

*While overlaying graphs in the "All SPL" tab you can average them together inside the software. This is an important and very useful feature! I always do 8 sweeps (8 measurements) on EACH SPEAKER, between each measurement I *move the microphone* a little (I'll explain this more in detail later...) When I got 8 measurements, I do a spatial average inside the software by selecting ALL GRAPHS (bottom of the screen) and click "Average the Responses" in the bottom left corner. You will now get a new "measurement" in the list to the left called "Average 1", this one represent all those 8 measurements as it's an average of all. 

_*[*]Important:* The "Average measurement" does only contain Frequency Response data. Do NOT remove the other measurements as they contain the impulse response which is needed for the more advanced functions and time data inside RoomEQ. _

_[*]In the modal range, i.e low frequencies, let's say below ~200Hz averaging is not really required. The response will not change very much over small distances. Use 1/24oct smoothing in this range._

_[*]Smoothing inside the software and "physical averaging" serve a similar purpose in a sense. _

Finally... *Save *each SET of measurements, as a separate file. The RoomEQ files will have a *.mdat file extension. These files can be sent to others for analysis, this is a neat feature since we can share files and help each other using objective hard data. The mdat file contain the full impulse response and all advanced features can be accessed through it.

*Use the "Save all" button in top left or via the menu "File" / "Save all measurements". 

I will get into microphone placement and some tips and tricks next time and then back to RoomEQ and common DSP software, how equalization work etc. Stay tuned.


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## RoyAlpine

Great work! tons of info...


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## miniSQ

subterFUSE said:


> STICKY!
> 
> 
> My UMIK-1 should be arriving any day now. Your timing with this thread was perfect!


My UmiK-1 arrived a couple days ago...agreed..perfect timing. 

I was planning on using the software supplied with my Helix, is there a reason why i cant use that and should use RoomEQ instead?


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## Hanatsu

miniSQ said:


> My UmiK-1 arrived a couple days ago...agreed..perfect timing.
> 
> I was planning on using the software supplied with my Helix, is there a reason why i cant use that and should use RoomEQ instead?


Yeah... several. The Helix software is just an RTA, you can't do any real troubleshooting or observe the time domain with an RTA. RoomEQ can perform autoEQ with both graphic and parametric filtering. It got a better overlay, average and graph managing ability. Quicker to work with (imo). 

If you're just interested in the the overall FR, the Helix software works indeed. I'll present a few reasons why RoomEQ is better later on


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## Hanatsu

1fishman said:


> MUCH THANKS!!!
> 
> Any recomendations for a microphone?


ECM8000 is a good mic, I'm using it. It requires a preamp with phantom power.
UMIK-1 and Dayton OmniMic are also great, they are USB mics. The drawback is no ability to use loopback to measure delay etc. I've heard the USB mics can be noisy if you're doing precision measurements but idk really. No real experience with any of them, my ECM8000 has worked fine for the last 5 years


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## Hanatsu

*Microphone measurement technique*

_If you look in a manual of an auto-tune DSP or ask 10 different 'experts' I'm sure you get different answers every time. I will present my technique here, in my experience, it has worked best in those systems I've installed. I've sort of 'back engineered' this technique via comprehensive listening tests... _

*So how do you place your microphone while measuring?*

Good question! Sit in the car, hold the microphone as the pictures below describe. Run one sweep in RoomEQ for EACH POINT. 8 sweeps in total for each individual speaker. Hold the microphone still while running the sweep and make sure the microphone doesn't hit your head or anything. 

*FOR SUBWOOFER MEASUREMENTS, A SINGLE MICROPHONE PLACEMENT IS ENOUGH. PLACE IT IN THE MIDDLE OF THE HEADREST OR IN FRONT OF YOUR HEAD (you don't even need to be in the car for this one)*

- As I said before, measure in a quiet area. 
- Measure at moderate/"normal listening" volume ~90dB or so. 
- Use hearing protection if you want, the sweep is annoying to listen to.







*!! AVERAGE THE MEASUREMENTS FROM THESE POINTS AS DESCRIBED IN MY LAST POST !!*

*Why 5/3 ratio for the left side and 6/2 ratio for the right side?*

I believe this is due more "hearing crosstalk" left side, the speaker is more in front of us and also closer to both ears. The listening tests confirm that this is the "best" way to average (IME).

Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


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## Hoptologist

Thank you for doing this. I was planning to look for some guides in the coming weeks, so this is awesome. Will be trying this out in the home too.


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## subterFUSE

Hanatsu said:


> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


What kind of charger do you use?

I have a charger at home but was never sure it was safe to use with the stereo running.

This is what I have: http://www.autozone.com/autozone/accessories/Schumacher-200-30-10-Amp-manual-battery-charger-starter/_/N-2604?itemIdentifier=837551_0_0_


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## Hanatsu

subterFUSE said:


> What kind of charger do you use?
> 
> I have a charger at home but was never sure it was safe to use with the stereo running.
> 
> This is what I have: Schumacher/200/30/10 Amp manual battery charger/starter (SE-3010) | Battery Charger | AutoZone.com


Hm... should be ok. Set it at 10A perhaps... 

I got this one:

MXS 25

It's an electronic "smart" charger built for AGM batteries.


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## Justin Zazzi

Great work Hanatsu, I really look forward to seeing this develop further.

Do you plan to talk about connecting the 2nd channel in a "loopback" configuration? I find it is exceptionally useful for time alignment.


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## I Love BMW

Wow ive been looking for something like this thanks a lot!


Sent from my iPhone using Tapatalk


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## moparman1

Subd


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## schmiddr2

This will likely be stuck. Please upload the images using the "Attach File" so even if you change the url they will remain.


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## miniSQ

Hanatsu said:


> Yeah... several. The Helix software is just an RTA, you can't do any real troubleshooting or observe the time domain with an RTA. RoomEQ can perform autoEQ with both graphic and parametric filtering. It got a better overlay, average and graph managing ability. Quicker to work with (imo).
> 
> If you're just interested in the the overall FR, the Helix software works indeed. I'll present a few reasons why RoomEQ is better later on


I get that RoomEQ is more powerful than the Helix software, but how do i then apply the settings that i view in roomEQ to my vehicle?


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## Hanatsu

miniSQ said:


> I get that RoomEQ is more powerful than the Helix software, but how do i then apply the settings that i view in roomEQ to my vehicle?


I will explain that in the next post... probably today 

Tapaaatalk!!


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## BlackHHR

subbed


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## crackinhedz

I have a Dayton umm-6 usb mic, which says its A weighted. 

The options in REW is "C weighted" or "Mic or Z weighted", which one should be selected?


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## Hanatsu

crackinhedz said:


> I have a Dayton umm-6 usb mic, which says its A weighted.
> 
> The options in REW is "C weighted" or "Mic or Z weighted", which one should be selected?


That's kinda weird. If you load the calibration file the weighing will be disregarded inside the range of the cal file. Choose Z otherwise.


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## crackinhedz

Hanatsu said:


> That's kinda weird. If you load the calibration file the weighing will be disregarded inside the range of the cal file. Choose Z otherwise.


yes I have the calibration file loaded and "mic or Z weighted" selected. Thanks for this helpful guide as I just installed REW and was not sure where to begin! Thanks


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## Hanatsu

*Setup your system, Pt1: Interpret your measurements *

OK. We had three parts so far. You should be a little more familiar with the software and how to do the "actual measurements" now but we won't jump into the advanced features just yet. First we need to understand what the measurement actually describes, what we can do with it and why we need equalization in a car. I'll try to keep it as simple as possible.

_Even if this is a measurement tutorial I think that knowing some of the basic theory how we interpret sound is a good thing. It allows you to understand what you're doing and WHY you are doing it._

*So, first some quick facts how we humans interpret sound, how we localize sound and why it's important. *


[*] At low frequencies we localize sound based on the time it takes for the sound to travel from one ear to the other. This is called the "inter-aural time difference (ITD)". ITD is the main contributor for sound localization below ~800Hz. 


[*] At high frequencies we localize sound based on the intensity (volume/level) difference between the ears. This is called the "inter-aural intensity difference (IID)". IID is the main contributor to sound localization beyond ~1600Hz.


[*] Between 800-2000Hz there's "gray area" where both IID and ITD contributing to sound localization and in the area 1000-3000Hz it's harder to pin-point where sound originates from than usual. Good to know when tuning.

Why is this important? Because if we want a good soundstage, with the vocals centered and a stable focused stage we need to consider both the difference in physical distance between speakers and the intensity difference altered by the interior of the car. 

*Some headunits and basically all DSPs got a feature called 'Time Alignment' which is used to delay the speakers closest to you and therefore electronically compensate for the distance difference between left and right side speakers. T/A (Time Alignment) mainly affects the 'ITD frequency range'.

*Few headunits and many DSPs got channel independent equalization (L/R EQ). EQ is basically a "frequency selective volume adjuster", that makes sense to you? To compensate for the intensity difference between the left and right side we need equalization on both channels. As you might guess, the L/R EQ function affects the 'IID frequency range' to a great extent, but it does also affect the 'ITD frequency range' in a way* (I'll discuss this and the 'modal range' later on).

Basically L/R EQ and T/A go hand in hand. You need both for correct tonality and staging. That's why a DSP is so important, all car audio systems need processing of some kind to sound right.

See the picture below for an illustration:









OK. Let's return to RoomEQ again... If you have followed the previous instructions in measuring all individual speakers and several averaging points of each, you could end up with something like this:









This is just an illustration of the mess of trying to manage every graph at the same time (not smoothing the graphs add to the mess). If you want to avoid this, first deselect all graphs (see picture below) and then select the graphs you want to work with. 









For this little example I selected the subwoofers (remember to set an appropriate graph frequency and level limit for easier viewing).









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

*Various good-to-know facts before you get started. *

## OK. I'm going to go through some various things before going into the fun stuff. First off:

*There's a big misconception about crossovers!*

*[1.] * So you enter your desired crossover points and slopes in the DSP and that's it, right...? Unfortunately, there's two "forms" of crossovers. One of the "forms" exist in the electrical domain and one in the acoustic domain. The ones you set in the DSP is the ELECTRICAL CROSSOVERS and they *NOT* the same as an acoustic crossover.

*[2.] * The ACOUSTIC CROSSOVER is the MEASURED crossover point and slope (as in 'measured with a microphone inside the car - in listening position'). This is "real" crossover point, the electrical crossovers can be set in any way you want as long as you reach the "optimal" acoustic crossover point/slope.

*[2a.] * Tip: Use different crossover points and slopes, left and right side to fix some of the frequency response errors BEFORE EQing the system. (We'll discuss this in detail later). 

*[3.] * The actual (acoustic) crossover point is dependent on the relative level/volume of two speakers.* IMPORTANT!* See pictures below:

"Normal levels"








Midwoofers levels are offset by +10dB and resulting crossover point changes as you can see.








This might be an eye-opener for some 

*So how bad can it be? Do we really need a DSP?*

The picture below speak for itself. This is a typical door mounted speaker frequency response (fullrange, no EQ, same input level between L/R speaker).









15dB difference! Right in the smack of the lower midrange (vocal fundamentals lies here). That can't be good... I promise, it isn't. We can do "some work" by being creative with levels and crossovers but we're still going to need equalization here to level out the difference. As you might understand by now, an ordinary EQ is not enough, you need a channel independent EQ to compensate for such issues as in this example...

That's it for now... I have few more things I want to add but soon we're going to discuss the fun stuff


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## subterFUSE

Question. Should the Time Alignment be measured and determined before performing these room measurements and EQ with REW?


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## Hanatsu

Doesn't matter. I do it before.

I'll will write up the next part soon, very busy at the moment.


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## subterFUSE

Hanatsu said:


> Doesn't matter. I do it before.
> 
> I'll will write up the next part soon, very busy at the moment.


Cool. I figured it best to do time alignment first.

I'm waiting for my Behrenger mic to arrive. Going to use my MacBook Pro with REW and an Allen & Heath Xone DB4.  
It will be overkill on the soundcard, but should work. That way I don't need to buy something new.


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## subterFUSE

My microphone is being delivered today. Really excited to start working with REW. 

Going to do time alignment first, and then check the response and work on my EQ.


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## Hanatsu

All right. Let's continue from my last post.

*Setup your system, Pt2: Equalization theory*

This is where I left off last time... If we look closely at the picture below we can see that there are peaks and dips in the response, it has a response deviation of 20dB from the highest peak to the lowest dip.








_PICTURE 1 (Subwoofer Measurement, Sealed enclosure - Measured inside car)_

A response deviation as large as 20dB is an issue, it WILL be audible and affect the tonal balance severely. As you may know, EQ is a feature to compensate for frequency response errors such as the graph shows, but can all response issues be 'fixed' with EQ and if not, why?

*[*]* As you boost with EQ, you will demand more more power from the amplifier in the EQ'ed area. A 3dB boost equals twice as much power and 6dB equals four times the power! 

This goes both ways, if you cut with EQ you will demand less power from the amp.

*[*]* EQ will affect the speaker's performance in more ways than you might think. I won't go into detail of this but as you increase volume a speaker's _(non-linear)_ distortion level will also increase. As EQ basically is a frequency selective volume control you will increase or decrease distortion if you boost or cut in a given area. 

*[*]* Some areas can't be EQed, large dips in the response, especially those low in frequency 'in the modal range', should be left alone. They are related to the speakers locations, the listening position and the inner dimensions of the car. Problems around 60-80Hz and 120-160Hz are common in average sized cars _(see "picture 1", the dip at ~65Hz is one of these issues)_. These areas can actually be viewed inside RoomEQ and this is an 'advanced feature' I will discuss later...

There can be cancellations in the response due to phase inconsistencies as well. Incorrect set time delay between speakers or incorrect polarity are common issues that can result in dips in the response. The response dip will not respond well to EQ in this case.

*Before I describe how to use the autoEQ of RoomEQ/REW, you must understand the basics of equalization...*

There are basically two types of EQ's available in most car audio DSP's and headunits. They are called "Graphic Equalizer" or "GEQ" and "Parametric Equalizer" or "PEQ" in short. A graphic EQ is easier to use, but also less powerful than the parametric type. Since parametric equalization is so widely used nowadays I will put some focus on that.

*Graphic, "Semi-Parametric" and "Full-Parametric" EQ*

A graphic EQ is the "normal" type of equalizer most people probably have seen in both home audio and car audio at some point. A GEQ has a varying number of EQ bands, which are centered around FIXED frequencies. The better units often got EQ bands with 1/3 octave spacing, i.e 200Hz, 250Hz, 315Hz, 400, 500Hz etc. Each of these frequency bands also got a FIXED BANDWIDTH, this means that if you choose to decrease 500Hz by 10dB, you won't simply lower just 500Hz, the frequencies around 500Hz will also be affected. That's why we call each EQ band "Center Frequency" . The area around the 'center frequency' is called "Bandwidth". The bandwidth is defined as "Q". A larger "Q"-value means a NARROW bandwidth (only the frequencies close to the center frequency are affected), a smaller Q-value have a WIDE bandwidth and will therefore affect a large amount of frequencies around the center frequencies.








_EQ bandwidth (Q's)_


*With a GEQ you will have FIXED center frequencies with a FIXED spacing and each center frequency will have a FIXED bandwidth (Q). This type of equalizer is easy to use but not as flexible as a parametric EQ.

*A parametric CAN be used in the same way as a graphic EQ. With a PEQ you gain the ability to CHANGE center frequency and bandwidth (Q). This type is more advanced to setup but is far more powerful if used correctly. A "full parametric EQ" will basically allow you choose whatever center frequency you want freely and a wide range of Q values. A "semi-parametric EQ" will allow you to change center frequency in a fixed octave spacing.

Example; You have an issue at 140Hz in the frequency response that needs EQing. With a good graphic EQ you should have EQ bands at 125Hz and 160Hz, unfortunately you won't be able to touch 140Hz without affecting the the frequencies around 125 and 160Hz as well. A parametric EQ allows you to choose a center EQ-band at 140Hz and the desired bandwidth (Q) to only attack the problem directly without touching the 125 and 160Hz bands.

*How to EQ...*

*Generally speaking, never use narrow band (high Q) EQ in the higher frequencies!

*Higher Q equalization/filters should only be used within the modal range (lower frequencies).

*Rather cut than boost. Remember the speaker strain and power requirement when boosting. I generally recommend not to boost more than 3dB.

*If the the frequency response doesn't respond to boosting an area by equalization, DON'T USE EQ there. You will only increase distortion. 

*Don't be afraid to use large amount of EQ in problem areas, it's the acoustic response that matters.

*Make sure levels and crossovers are optimized before EQ. IMPORTANT!*

The optimization of levels and crossovers will therefore be be first step in setting up your system and I will discuss this in detail in PART 3. So you who have been waiting for the practical tutorial in RoomEQ will be happy next time 

Until next time ^^


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## calebkhill

Hurry please


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## calebkhill

Maybe a quick tip on level and crossover setup?


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## Hanatsu

Almost midnight here. Gotta sleep 

You'll have a detailed post tomorrow.


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## calebkhill

Lol. Nooo.


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## mmiller

Sub'd


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## fig32

This is great, anxiously awaiting the next installment of "Newbees Tune Your Ride". I recently started using REW and this really helps clarify some of the things I need to do. Hope you got a good nights sleep!


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## subterFUSE

Tried to get started with the time alignment portion today, but can't get my soundcard inputs to display in the REW preferences properly. Only shows Left or Right, but my soundcard has 4 channels of L/R input/output.

Going to try on my PC laptop this time to see if it's just because it doesn't like the Mac CoreAudio drivers.


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## calebkhill

Wish there was a better USB Mic method.
I use a usb Mic, so I'm doing the "invert one speaker, delay until most destructive interference at the crossover point" method


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## subterFUSE

calebkhill said:


> Wish there was a better USB Mic method.
> I use a usb Mic, so I'm doing the "invert one speaker, delay until most destructive interference at the crossover point" method


Yeah, I have a UMIK-1 and a Behringer mic.

Was trying to get the Behringer to work so I could do the time alignment, but still can't get it working. I'm using a mixer for the mic preamp but no matter how high I turn up the gain and levels, it's still saying too low.


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## Hanatsu

*Setup your system, Pt3: Adjust L/R Levels*

_*"The following two parts will show how to set up levels and crossover points correctly, before EQ"*_

Alright, let's begin with setting up L/R levels properly. This step should be done before EQing your system. For this part I'm going to assume you have read my previous post about 'electrical vs acoustical crossover points' and 'how to measure' and so on. Time for the boring theory lesson to pay off. We will also begin discussing the subject of target responses, which is the main point in performing "response shaping". 

*** Levels, Crossovers and EQ are tools to shape the response to a desired curve. Focus on what happens in the acoustic domain and less how the electrical filters look ***

*Let's begin, step for step:*

*Step 1. *Choose a desired target response. What works or doesn't is highly individual for each install and car interior size. I will supply a 'generic' curve that we'll use in this example. 

Here's a informative thread that discusses different target responses if you're interested...

*Step 1a. *Load this file into RoomEQ: *
View attachment generic target curve.txt
*

_You load the file by going into "Preferences" / "House Curve" (Make sure 'Use Logarithmic Interpolation' is checked.)_

*Step 2. *Set all drivers to fullrange, i.e bypass/disable all crossover filters in the DSP/HU or on the amplifiers. *Exception!!* Place a HIGHPASS FILTER (HPF) on all Tweeters and dome midranges, a fullrange signal might damage the drivers! A 24dB/oct HPF 1/2 octave _(1,5 times the Fs value)_ above resonance (Fs) will be sufficient to protect the drivers and still get a proper "fullrange" signal out of them. Check the speaker's data sheet to find the resonance frequency (Fs), most manufacturers supply that kind of data.

*Step 3. *Measure all speakers individually. It doesn't matter if you don't have speaker independent EQ or not. Do NOT touch the volume control, gains or any other settings during the measurements. Use 'normal' listening levels during the measurements. It should look something like the picture below after this is done. (Read the previous posts on 'Managing measurements' if you don't understand this.) 








_"Picture 1. After individual measurements."_

*Step 4. *Now we'll start with level matching the speakers to each other. We want as similar response from left and right side, with each set of drivers. This is the tricky part, you can level match with both levels and the crossover settings sort of. There's a few ways to do this step, there's no right or wrong. I'll present an option here but first we need to check the overall levels off all measurements to check that they are not too far off. 

*Step 4a.* Set smoothing off all plots to 1/1oct. Now it should look like this:








_""Picture 2. After 1/1 smoothing applied."_

*Step 4b.* Select left/right side measurements for each set of drivers. For example, (left & right midbass) together and (left & right tweeters) together. See picture below. Repeat for each set of drivers.








_""Picture 3. Zoomed in view. Average level difference, left/right side"_

*Step 4c.* Make the the necessary changes in your DSP or HU. Lower the side with the loudest overall response by the appropriate amount, in the example above the average level was about 3-4dB too high on the the driver side, YMMV. All DSPs I've seen have a separate level control on each speaker, it's often located in the crossover section of the interface.








_""Picture 4. Zoomed in view. Average level difference, left/right side - AFTER LEVEL ADJUSTING IN DSP"_

The picture above shows how the drivers now are better level matched on an average basis. 

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

*Step 4d.* When you have done the level matching for each set of drivers it's time to check how they compare to each other, i.e how the levels between subwoofers --> mids --> tweeters look. IMPORTANT! Remember that the levels should NOT be the same here, they should match the target response we loaded (which isn't flat). I'll explain this in the next step.

*Step 5.* Select one of the measurements in the left row, for example the subwoofer measurement. This one will be used as a reference. See picture below:








_""Picture 5. Zoomed in view. Select the "reference" driver and go into the EQ tab."_

*Step 6.* When you inside the EQ menu, you need to make some adjustments. See picture below:








_""Picture 6. EQ MENU"_

*Step 6a.* Select the type of DSP you got, if it's not in the list. Choose "Generic".

*Step 6b.* 









*Set "Speaker Type" to "Full Range". 
*Set "LF Cutoff (Hz) to "0".
*Set LF Rise Slope (dB/octave) to "0".
*Set HF Fall Slope (dB/octave) to "0".

*Step 6c.*

Set "Target Level (dB) to match the measurement you loaded. See "picture 6". Set it so the level is close to the target response. It doesn't need to be 100%, we will EQ that later. *IMPORTANT!* The "Target Level" you choose will be the "REFERENCE Target Level". Make note of this number for later.

_Next time we'll continue to setup crossovers and levels for each 'type' of drivers to match the target response by using autoEQ._


----------



## Hanatsu

I'll continue writing this tomorrow, I'll just continue where I left off (it's incomplete so far)


----------



## sar1rs4

this is awesome man!. 
i have just finished my first ever install and this site has been an excellent source of info.
i have read loads about REW and my UMIK-1 mic has just come from cross spectrum labs so this is excellent timing!
many many thanks hanatsu and to everyone else who's threads have been so much help.


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## calebkhill

Awesome. This is epic.
Hopefully by the end of this, and hopefully it'll be ongoing , US noobs can refer here fur anything we need in rew.
Someone should take these posts and compile them into an organized "book" . That'd be serious.


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## fig32

Couldn't agree more. We should make this thread a sticky so people just coming here can benefit without having to search too much. I have watched a bunch of videos and read so many threads on REW and similar products. I think this thread is the best so far. Looking forward to tomorrow's post! Now I just need to make some time to get back into my car and continue tuning. Damn work keeps getting in the way!


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## rdlhifi

Sticky xxx!


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## bbfoto

Hanatsu. Thank you. Please Provide a Pay Pal DONATE Link for your time, experience, and effort in putting this together. This information, as presented here in a step-by-step guide, is worth at least as much as the DSPs we use in our systems to make these adjustments and corrections.


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## subterFUSE

So I have just spent about 2 or 3 hours trying to to use REW for time alignment measurements, and I'm completely lost. I've printed out the instructions from the link at the beginning of this thread, but for the life of me I can't figure out how to do this.

I have a Behringer ECM8000, connected with XLR cable to a phantom power device, and then into the Mic input on my mixer/USB sound card. I know that I have the output from the soundcard playing correctly on my car stereo because I can hear the test sweeps/****e noise tests. And I know that I have the microphone connected properly because it is detecting and measuring the signals played over the car stereo. But I can't get the loopback working, or I don't know how to get the loopback working.
I'm kicking myself because I have a degree in physics but I can't figure this out.


----------



## Hanatsu

Do the soundcard got ASIO support? I might have to return to the T/A issue later to provide an alternitive way to do it without the use of 'loopback'... Thanks for the kind words everyone btw 

Tapaaatalk!!


----------



## SPLEclipse

subterFUSE said:


> So I have just spent about 2 or 3 hours trying to to use REW for time alignment measurements, and I'm completely lost. I've printed out the instructions from the link at the beginning of this thread, but for the life of me I can't figure out how to do this.
> 
> I have a Behringer ECM8000, connected with XLR cable to a phantom power device, and then into the Mic input on my mixer/USB sound card. I know that I have the output from the soundcard playing correctly on my car stereo because I can hear the test sweeps/****e noise tests. And I know that I have the microphone connected properly because it is detecting and measuring the signals played over the car stereo. But I can't get the loopback working, or I don't know how to get the loopback working.
> I'm kicking myself because I have a degree in physics but I can't figure this out.


You might have to go through and try a bunch of options under the soundcard tab to get things working. You might get a "clipping detected on the reference channel" error, or "signal too low" error because the software thinks it's listening for the sine sweep in that channel and not the reference signal it's getting. I know that the clipping error is OK, as I get it when I'm testing. I've never gotten the "signal too low" error, but that might be fine too if you're still getting reliable impulse readings. This is all assuming you have the capability to use a loopback with the soundcard.

If you can't use a loopback, you can use HolmImpulse. It uses a clocked "stream" that is uninterrupted between measurements. In this way it can't give you absolute impulse, but it can give you comparative impulse between two signals. It's trickier in that the order you measure the speakers in matters, and you can't run any memory-intensive applications while using it or you'll interrupt the stream, but I'll let Hanatsu take care of explaining it, lol.

If it comes down to it you can buy a super inexpensive non-calibrated mic and use it without the external card just for impulse response.


----------



## subterFUSE

Hanatsu said:


> Do the soundcard got ASIO support? I might have to return to the T/A issue later to provide an alternitive way to do it without the use of 'loopback'... Thanks for the kind words everyone btw
> 
> Tapaaatalk!!


Yes, I've got ASIO and I'm using those drivers in the Prefs.

I have the output playing on channel 2 on my mixer/soundcard, which corresponds to soundcard channels 3 & 4.
I'm using the Record output from the mixer that uses RCA cables. The RCA cables go into my car and plug into the RCA input on my head unit. The microphone is on a stand in the driver seat, with the mic in the approx center of head position. The mic is a Behringer ECM8000, with XLR cable going into a phantom power device and then into the Mic input on my mixer, which is on channel 1. CH1 = soundcard channels 1 & 2.

In the soundcard routing, I have set mixer channel 3 (SC channels 5 & 6) to receive the Record output. This should effectively be the same thing as running a cable from the Record output back into mixer channel 3. It's just done via the soundcard routing instead of by a cable.

I know that I have the output working correctly because I can hear the signals being generated playing on my car stereo. I also know that I have the microphone connected and routed properly because it is recording the signals.
The level tests all come back OK.

I just can't tell if I have the loopback working or not. How do I tell if the loopback is working?


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## SPLEclipse

Make sure you check the box labeled "Use loopback as timing reference" under the "Analysis" tab. Take a measurement of one speaker with the mic in one position. Move the mic into the backseat or wherever. Take another measurement of the same speaker Compare impulse response to see if it has changed in a reasonable way. If you moved the mic 2 feet back, you should get an impulse peak that's about 1.8ms after the first one (2/1100 =0.0018 seconds).


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## subterFUSE

Thanks for the help. I did have the loopback button selected.

I am actually thinking I might have had it done correctly last night, but just didn't understand how to read the charts.

I'll try again tonight when I get home.


----------



## Hanatsu

Sorry guys for not updating. I was in a traffic incident yesterday morning, I hurt my foot and left leg pretty bad. There will be a few days before I'm released from hospital, hope you'll have patience heh


----------



## ErinH

moved to the tutorials section annnnnnnnnnnnnnnnnnnddddd...... STICKIED!


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## venki7744

Hanatsu said:


> Sorry guys for not updating. I was in a traffic incident yesterday morning, I hurt my foot and left leg pretty bad. There will be a few days before I'm released from hospital, hope you'll have patience heh


Take care sire and get well soon.


----------



## subterFUSE

Hanatsu said:


> Sorry guys for not updating. I was in a traffic incident yesterday morning, I hurt my foot and left leg pretty bad. There will be a few days before I'm released from hospital, hope you'll have patience heh


Wow! Sorry to hear. Hope it's not too bad, and you'll be getting well fast.


----------



## fig32

Hope it is just bumps and bruises. Get well soon and take your time, sorry to hear you got into an accident.


----------



## subterFUSE

So I am about to go and start getting the equipment hooked up so I can try another go at this with REW.

Wish me luck.

Working in my favor, I already finished half a bottle of Sancerre. The remaining half is still beckoning.

I discovered this morning that my Audison BitOne DRC controller has decided to present an interesting challenge to complicate things for me. (See attachment)

Any suggestions? Perhaps a toothpick and some chewing gum?


----------



## bbfoto

subterFUSE said:


> I discovered this morning that my Audison BitOne DRC controller has decided to present an interesting challenge to complicate things for me. (See attachment)
> 
> Any suggestions? Perhaps a toothpick and some chewing gum?


Bummer.  Shop Vac? Kids dart gun "bullet" with suction cup? LOL!


HANATSU! Hope it isn't too serious.  Hang in there and get well!


----------



## subterFUSE

I think I got REW working this morning, but I'm still not certain. So I took some pics of the measurements I made and hopefully someone here can help?
I just can't tell if I have the loopback reference working properly.

Here are the midbass drivers. I muted all drivers but one at a time and measured. Microphone in drivers seat at center of head position.


----------



## Patrick Bateman

Hanatsu said:


> *Microphone measurement technique*
> 
> <snip>
> 
> *!! AVERAGE THE MEASUREMENTS FROM THESE POINTS AS DESCRIBED IN MY LAST POST !!*
> 
> *Why 5/3 ratio for the left side and 6/2 ratio for the right side?*
> 
> I believe this is due more "hearing crosstalk" left side, the speaker is more in front of us and also closer to both ears. The listening tests confirm that this is the "best" way to average (IME).
> 
> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


Gary Summers showed me a neat setup he has for his Mercedes. It's basically an array of microphones in an aluminum jig. By using a jig he can insure that the mic is in the same place, every time.

It would be fairly simple to build a box that could allow one to 'turn on' each mic, one by one, so that you could do your measurements without even getting up to move the mic. Taken a step further, the software itself would do the switching between the array of mics, but I've never seen any software that can do that. (I use the free stuff, Arta and HolmImpulse.)


----------



## Patrick Bateman

subterFUSE said:


> So I have just spent about 2 or 3 hours trying to to use REW for time alignment measurements, and I'm completely lost. I've printed out the instructions from the link at the beginning of this thread, but for the life of me I can't figure out how to do this.
> 
> I have a Behringer ECM8000, connected with XLR cable to a phantom power device, and then into the Mic input on my mixer/USB sound card. I know that I have the output from the soundcard playing correctly on my car stereo because I can hear the test sweeps/****e noise tests. And I know that I have the microphone connected properly because it is detecting and measuring the signals played over the car stereo. But I can't get the loopback working, or I don't know how to get the loopback working.
> I'm kicking myself because I have a degree in physics but I can't figure this out.


This is Windows right?
Usually the reason that the loopback doesn't work is that stupid Microsoft Windows has the input of the soundcard set to mono. When this happens, one of two things occurs:

1) one channel is muted, so your loopback no worky
2) or the left channel is duplicated to the right channel, so your loopback no worky

Right click on the properties of the speaker icon in Windows, select input, go to the properties and set it to "44.1khz stereo" (default is mono.)

This same stupid problem screws up measurements in HolmImpulse, Arta, Dayton Woofer Tester, and on and on and on


----------



## Patrick Bateman

subterFUSE said:


> So I am about to go and start getting the equipment hooked up so I can try another go at this with REW.
> 
> Wish me luck.
> 
> Working in my favor, I already finished half a bottle of Sancerre. The remaining half is still beckoning.
> 
> I discovered this morning that my Audison BitOne DRC controller has decided to present an interesting challenge to complicate things for me. (See attachment)
> 
> Any suggestions? Perhaps a toothpick and some chewing gum?


Blu Tak.


----------



## ErinH

Patrick Bateman said:


> Gary Summers showed me a neat setup he has for his Mercedes. It's basically an array of microphones in an aluminum jig. By using a jig he can insure that the mic is in the same place, every time.
> 
> It would be fairly simple to build a box that could allow one to 'turn on' each mic, one by one, so that you could do your measurements without even getting up to move the mic. Taken a step further, the software itself would do the switching between the array of mics, but I've never seen any software that can do that. (I use the free stuff, Arta and HolmImpulse.)


he actually posted a picture of that _somewhere_... I don't remember where, but I seem to recall him posting it a couple years ago. maybe I'm wrong... wouldn't be the 2nd time. 


That said, I don't think that's necessary, really. it's cool. but overkill, IMO. and it sure wouldn't be cheap or easy. the whole reason you're doing it is for accuracy, correct? well, what about accuracy of the mic? you're gonna have to load multiple cal files or have all mics measure exactly the same. that's a whole lotta work for what I feel would be no gain. Just my $.02 on it, though.


----------



## Patrick Bateman

bikinpunk said:


> he actually posted a picture of that _somewhere_... I don't remember where, but I seem to recall him posting it a couple years ago. maybe I'm wrong... wouldn't be the 2nd time.
> 
> 
> That said, I don't think that's necessary, really. it's cool. but overkill, IMO. and it sure wouldn't be cheap or easy. the whole reason you're doing it is for accuracy, correct? well, what about accuracy of the mic? you're gonna have to load multiple cal files or have all mics measure exactly the same. that's a whole lotta work for what I feel would be no gain. Just my $.02 on it, though.


whoah I couldn't disagree more strongly.
A measurement at a single point in a car is virtually useless.
There are so many reflections, if you rely on a single data point your measurement is virtually worthless.

When measuring in the car, I use one of two options:

1) measure the system at multiple points and average the measurements (basically what Hanatsu is doing)

or

2) measure the speakers outside of the car


I generally start with option 2, then move to option one once I'm happy with the outside measurement.

As far as accuracy of the mic goes, I think that the dips and peaks caused by the car swamp any dips and peaks inherent to the mic. If you look at a typical calibration file the adjustments are usually along the lines of about +/- one decibel, whereas a single reflection in a car can create a 20dB dip.


----------



## ErinH

whoa, yourself there, big fella. 

I've been 'preaching' spatial averaging for years now:
http://www.diymobileaudio.com/forum...-rta-tuning-importance-spatial-averaging.html

What I'm saying is I don't think there's a legitimate enough benefit in having 6 mics set up at the same time with a duplex switcher for the array on top of having to worry about the calibration of each. Using REW and a high number of averages while sitting in the car with the mic is my preferred method. And it's extremely accurate as long as the location is in the same area, given the high number of data samples the software is obtaining and averaging on the fly.


----------



## Regus

Hanatsu said:


> *Microphone measurement technique*
> 
> _If you look in a manual of an auto-tune DSP or ask 10 different 'experts' I'm sure you get different answers every time. I will present my technique here, in my experience, it has worked best in those systems I've installed. I've sort of 'back engineered' this technique via comprehensive listening tests... _
> 
> *So how do you place your microphone while measuring?*
> 
> Good question! Sit in the car, hold the microphone as the pictures below describe. Run one sweep in RoomEQ for EACH POINT. 8 sweeps in total for each individual speaker. Hold the microphone still while running the sweep and make sure the microphone doesn't hit your head or anything.
> 
> *FOR SUBWOOFER MEASUREMENTS, A SINGLE MICROPHONE PLACEMENT IS ENOUGH. PLACE IT IN THE MIDDLE OF THE HEADREST OR IN FRONT OF YOUR HEAD (you don't even need to be in the car for this one)*
> 
> - As I said before, measure in a quiet area.
> - Measure at moderate/"normal listening" volume ~90dB or so.
> - Use hearing protection if you want, the sweep is annoying to listen to.
> 
> 
> 
> 
> 
> 
> 
> *!! AVERAGE THE MEASUREMENTS FROM THESE POINTS AS DESCRIBED IN MY LAST POST !!*
> 
> *Why 5/3 ratio for the left side and 6/2 ratio for the right side?*
> 
> I believe this is due more "hearing crosstalk" left side, the speaker is more in front of us and also closer to both ears. The listening tests confirm that this is the "best" way to average (IME).
> 
> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


I take it the 5/3 and 6/2 ratios are for a left hand drive car and that for a right hand drive car (or passenger seat measurements if you were so inclined) you would reverse these?

As regards spacial averaging, I haven't been able to read through the other thread yet, but would I be right in thinking we might want to repeat the measurements after EQing and determine whether the response (averaged across those same locations) was now more uniform or whether we needed to make further adjustments, and if this were the case it would be beneficial to have a means of using the same locations as we used originally. Whether this needs to be a jig of some kind or multiple microphones is a point worthy of more discussions, although I would be biased towards the simplest (and cheapest) solution and introduce the minimum number of variables by using the same microphone and calibration file throughout, as it introduces less chance of error from using the wrong calibration curve with a given microphone.


----------



## subterFUSE

Who managed to get Bruce Willis to pose for that diagram pic?

Talk about some serious connections....


----------



## subterFUSE

Patrick Bateman said:


> This is Windows right?
> Usually the reason that the loopback doesn't work is that stupid Microsoft Windows has the input of the soundcard set to mono. When this happens, one of two things occurs:
> 
> 1) one channel is muted, so your loopback no worky
> 2) or the left channel is duplicated to the right channel, so your loopback no worky
> 
> Right click on the properties of the speaker icon in Windows, select input, go to the properties and set it to "44.1khz stereo" (default is mono.)
> 
> This same stupid problem screws up measurements in HolmImpulse, Arta, Dayton Woofer Tester, and on and on and on


Yes, I'm using Windows because when I tried using my MacBook Pro it seemed that REW doesn't like the CoreAudio drivers. My mixer driver was not showing up as an option in the Preferences. But with my PC, I got the ASIO drivers working just fine.

I will check the Windows mono issue tomorrow, but I'm skeptical about this being the issue.
Besides, REW doesn't actually reference any of the inputs/outputs in stereo. They are all mono references because it only allows one input or output selection at a time. On my mixer, separate Inputs "1 & 2" are the same as channel 1 L/R on my mixer. 3 & 4 = CH2 L/R.
I'm trying to handle the loopback via the USB soundcard's internal routing. Not using a cable because that should be unnecessary with my mixer. (Allen & Heath Xone DB4) I know that the mixer I am using it WAY more advanced that what is needed for REW, but I didn't feel like buying more equipment when this should theoretically work just fine.

Actually, I think I had it working this morning. I just don't really know how to confirm whether or not the loopback is working or not? See my previous post with my midbass measurements. Maybe someone can determine from the pics?


----------



## SPLEclipse

^^^Are your measurements (on the X axis) in milliseconds or meters? I've never gotten a measurement in the 200's range. Other than that it looks like a normal impulse response. Do you have the driver in blue wired in reverse polarity?


----------



## subterFUSE

SPLEclipse said:


> ^^^Are your measurements (on the X axis) in milliseconds or meters? I've never gotten a measurement in the 200's range. Other than that it looks like a normal impulse response. Do you have the driver in blue wired in reverse polarity?


Thanks for the reply. I do not have my midbass wired in reverse polarity, but I was playing with the phase invert buttons on my BitOne previously. However, I feel 95% confident that I reverted the phase button back to normal before running that test this morning.

I'm not sure about the x-axis, because I've only just begun using REW. I will revisit this in the morning before work.


----------



## Hanatsu

Got home today... I'll continue with the next part soon


----------



## calebkhill

Just got an email notification about this thread being updated soon? Now that's what you call supply and demand.


----------



## Regus

Hanatsu said:


> Got home today... I'll continue with the next part soon


Glad to hear you're back home - I'm sure the DIYMA crowd won't mind waiting a little longer for the next installment while you recuperate, so take as long as you need.


----------



## Hanatsu

*Setup your system, Pt4: Crossovers...*

RoomEQ isn't really designed for simulating crossovers in a "full system" but we can exploit some of the features for our goal. Setting overall levels and the crossovers are most straight-forward to do at the same time. Continuing off the last post we'll go through how to do this within the autoEQ section of REW.

*Our goal is to attain proper ACOUSTIC crossover settings, REW will simulate what's required to reach the target response and then REW will calculate the ELECTRICAL settings for you automatically (the settings you enter in your DSP) *

OK. I assume you've reached "step 6c" so I continue from there. We'll set crossovers now and later go back to levels. REW have the option of choosing between 12dB/octave or 24dB/oct, I believe the filter type is Linkwitz-Riley, which is good. A 24dB/oct L-R filter is easy to setup and it generally work great with a variety of drivers out there. I won't go into detail discussing slopes and filter types now, but a steep acoustic slope like 24dB/oct eliminates a number of problems. So I'm just gonna be bold and say that this is the best filter you can use for now.

*Step 7.*

*Make sure you use the same "Target Level" number throughout the entire process.









Let's discuss the "Target Settings" tab. The options of interest are "Speaker Type", "Crossover", "Cutoff(Hz)", "LF Slope", "LF Cutoff(Hz)" and of course "Target Level" mentioned earlier. Here's what they do;


[*] Speaker Type = Determines the type of filter used for the simulation. You can choose between; Highpass, Bandpass and No filter (fullrange). They are however named a little weird.

*"Fullrange"* = Highpass Filter (HPF), use this settings to simulate tweeter crossovers.

_*"Bass Limited"* = Also a Highpass Filter (HPF). No need to use it._

*"Subwoofer"* = Bandpass Filter (BP), contains both a Highpass and a Lowpass (LPF) section, use this one for all other drivers.

*"None"* = As it sounds, no crossovers will be simulated.


[*] Crossover = This is LOWPASS SLOPE setting. Set it to 24dB/oct.

[*] Cutoff(Hz) = Cutoff frequency for the Lowpass Filter, this is the "crossover point" REW will simulate.


[*] LF Slope = This the HIGHPASS SLOPE setting. Set it to 24dB/oct.

[*] LF Cutoff[/I] = Cutoff frequency for the Highpass Filter, this is the "crossover point" REW will simulate.

*The lowpass settings will only be visible when you selected "Subwoofer" in the "Speaker Type" menu.

*Subsonic is another name for a highpass filter, if you have a vented subwoofer enclosure, set the "LF Cutoff" frequency 10Hz below the tuning frequency of the enclosure (Fb) to avoid damage due to unloading.


*So where should you place your crossovers?*

*Good question and it kinda depends. Install, the driver characteristics, the driver type, the driver size and power handling all determine what settings are "optimal". It's actually a question better answered in another thread. In this tutorial we're gonna use some generic crossover points as an example.

I can say this though, you should not use any underlapping or overlapping of frequencies in REW's simulation. If you want the crossover to be at 100Hz you set driver1's LPF to 100Hz and driver2's HPF to 100Hz. The rest will be handled by the autoEQ algorithm.


*Step 8*

OK. Let's simulate our crossovers. As I said, REW doesn't have a "proper" function for this but we can exploit manual filters inside "EQ filters". This part needs to be done manually but don't worry - it's quite easy.









Enter the "EQ Filters" menu. Next you should see this popup screen;









This is where all filters, EQ and DSP settings end up. If REW performs autoEQ for you, here's where you look. More of that later, first we need to set the crossovers. This MUST be done before running autoEQ, otherwise the entire crossover slope will be created by EQ filters. 

If you look in the left row, it says "Auto" all the way. We need to change some to "Manual". That way, REW will leave them alone when running autoEQ later.









In my example I'm trying to setup a subwoofer. I want a 24dB/oct lowpass filter applied. To choose a lowpass filter we simply choose "LP" in the row called "Type". These filters are fixed at 12dB/oct so we need two of them to attain a 24dB/oct filter. To do this we simply create two filters with the same values. This is called "cascading filters" (creative users can even design multiple filters with different cutoff frequencies to shape the rolloff any way you want, this can only be done with the Mosconi DSPs as far as I know).

So 1 LP filter = 12dB/oct -- 2 LP filters = 24dB/oct -- 3 LP filters = 36dB/oct...









What I've done here is to set my desired crossover point to the right under "Target Settings" to 24dB/oct @ 65Hz. These settings are shown in the plot as a blue line, in other words - these are the "perfect" settings, the one you're trying to attain. In the "EQ filters" I've choosen 2x LP filters which equate to 24dB/oct. REW will simulate the settings you just made in the plot (the light yellow graph line). Here's the part where you manually need to setup the crossovers till the simulated response is as close to the BLUE line as possible. 

As you can see, the "electrical" settings in the "EQ filters" tab are set to 24dB/oct at 80Hz but the desired acoustic response is set to 65Hz. The only reason I have it 80Hz is because these settings gave me the closest resemblance to the "blue line" i.e the desired acoustic response.

For subwoofers without a subsonic filter applied, you only need 2 Manual LP filters. If you're doing a crossover simulation on a midrange driver you might want both a lowpass and highpass filter applied. This require 4 manual filters, 2x LP and 2xHP to attain a peoper 24dB/oct bandpass filter. 

I pause here... don't wanna lose the entire text if something were to happen with my computer lol...

*Highres pictures; Rew Guide2 Slideshow by Hanatsu2 | Photobucket*


----------



## Gary Mac

Subbing


----------



## venki7744

Hey Hanatsu,

Bumping up this thread to remind you the we are waiting anxiously for the next part ...I have been reading..re-reading...re-reading this thread again and again and I still have some questions:

* How do we go about deciding the target response (59db as shown in step 6 here:http://www.diymobileaudio.com/forum/2105035-post45.html)
* How do we go about deciding the target crossover point (65db) and does REW set the electrical crossover automatically.

Sorry for the noob questions. 

Cheers,
Venki


----------



## subterFUSE

Just spent my whole day working through this tutorial. I learned a hell of a lot about REW, and I got my time alignment measured, levels matched and X-Overs set. I think I know how to apply the EQ, too.... but I might wait for the next installment before proceeding.

The important thing is how much better my system sounds after today. Absolutely huge difference.


----------



## subterFUSE

A couple of questions:

1. The Target Level (dB) setting. Does that need to remain the same for all of the different speakers?

2. I understand the difference between the Electronic XOver vs. Acoustic XOver points. So how should we pick the desired Acoustic XOver frequencies?
Also, is it common for a subwoofer to require an electronic crossover of 130Hz in order to attain an Acoustic 70Hz?


----------



## venki7744

Hanatsu said:


> *Microphone measurement technique*
> 
> _If you look in a manual of an auto-tune DSP or ask 10 different 'experts' I'm sure you get different answers every time. I will present my technique here, in my experience, it has worked best in those systems I've installed. I've sort of 'back engineered' this technique via comprehensive listening tests... _
> 
> *So how do you place your microphone while measuring?*
> 
> Good question! Sit in the car, hold the microphone as the pictures below describe. Run one sweep in RoomEQ for EACH POINT. 8 sweeps in total for each individual speaker. Hold the microphone still while running the sweep and make sure the microphone doesn't hit your head or anything.
> 
> *FOR SUBWOOFER MEASUREMENTS, A SINGLE MICROPHONE PLACEMENT IS ENOUGH. PLACE IT IN THE MIDDLE OF THE HEADREST OR IN FRONT OF YOUR HEAD (you don't even need to be in the car for this one)*
> 
> - As I said before, measure in a quiet area.
> - Measure at moderate/"normal listening" volume ~90dB or so.
> - Use hearing protection if you want, the sweep is annoying to listen to.
> 
> 
> 
> 
> 
> 
> 
> *!! AVERAGE THE MEASUREMENTS FROM THESE POINTS AS DESCRIBED IN MY LAST POST !!*
> 
> *Why 5/3 ratio for the left side and 6/2 ratio for the right side?*
> 
> I believe this is due more "hearing crosstalk" left side, the speaker is more in front of us and also closer to both ears. The listening tests confirm that this is the "best" way to average (IME).
> 
> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


Got inspired and brought some human element to measuring , even though I have not started measuring. The mic would go into each of the holes and depth would be adjusted with some spacers.

Cheers,
Venki


----------



## rdlhifi

venki7744 said:


> Hey Hanatsu,
> 
> Bumping up this thread to remind you the we are waiting anxiously for the next part ...I have been reading..re-reading...re-reading this thread again and again...
> Cheers,
> Venki


x2


----------



## Hanatsu

Oh noticed that I never published the last part... I think I have a draft about half-done somewhere. I'll finish it the coming week, this summer has been hell. Haven't even had the time to sit in front of the computer until now :<


----------



## emoon3

Hanatsu said:


> *
> 
> 
> 
> *


*

Subbing to a great thread. I have one question. Is it necessary to have Bruce Willis do the calibration?*


----------



## Hanatsu

_Sorry for the delay, here's the final part. Continuing from the last post. REW has been updated and some changes have been made. When I first made this guide it worked perfectly fine to set crossovers manually first then run auto EQ, however, that does no longer work. It keeps reseting the crossover settings when you do this in the current version. This means we need to set crossover settings after you've run EQ. I had to modify the last part due to this..._

(I lost my project file so don't mind my settings...)

*Setup your system, Pt5: autoEQ (Final)*

*Part 9.*

It's finally time to EQ.

I prepared filters for 16 band GEQ's, 31 band GEQ's and 31 band PEQ's. This should cover the majority of DSP's and also the popular Pioneer 80PRS and P99RS. 

*16-band Graphic EQ FILTER (Pioneer 80PRS)

31-band Graphic/Parametric EQ FILTER (DSP)*

Download the filters and choose the appropriate filter for the speaker you're applying EQ to. Due to REW's 20band restriction we can't utilize 31 bands in the filters tab, however, it's rarely required if you got a parametric EQ.

_-Do a final check that you have the target level, crossovers on "manual" and got the correct house curve loaded._









Load the filters, now it should look something like this;









Before you do any EQ, make sure that the simulated crossovers match the desired crossover settings as much as possible. Simply adjust the crossover settings in the "EQ filters" tab until the graph resembles the blue line (representing the simulated target). *Remember the adjusted settings (the crossover frequency you set)*

















As you can see, the lines match up much better now. Now finally we can EQ.

---Close the "EQ Filters" window.

*Now we need to take a look at the "Filter Tasks" tab, it's here we decide what the EQ algorithm is supposed to do.*









The settings here are the following:

*Match range: This is range you want to apply EQ to. One octave outside the -f3 point of the crossovers is adequate. For example; if you wanna EQ a midbass driver and the crossovers are set at 50-500Hz, you can set the EQ match range from 25-1000Hz. You can of course set the match range even higher than that but it's normally not required.

Individual Max Boost/Overall Max Boost: This is how much boosting you want to allow for. I quote REW's help file;



> Individual Max Boost sets the maximum boost that REW will allow for any individual filter. This can be set to zero to prevent REW assigning any boost filters.
> 
> Overall Max Boost sets the maximum boost that REW will allow for the combined effect of all the filter. This can be set to zero to prevent REW allowing any overall boost, but individual filters may still have boost.


I recommend setting "overall boost" to max 3dB (that's twice the power requirement if you don't alter gain settings in the DSP or at the amps afterwards). Individual filters can be set slightly higher since REW will use combinations of boosts/cuts to achieve an EQ filter target.

Flatness target: This is how precise you want REW to be when assigning filters, I usually set this at 1 or 2dB.

OK. Now there's a little extra step you need to do (because of the bug or whatever, dunno if this will be resolved in the future. I'll notify the author of this).

Here's the quick rundown:

1. Load the filter,
2. Set "Speaker Type" to "None" in the "Target Settings" tab.
3a. If you got a graphic EQ, like a Pioneer 80PRS, click on *Optimize Gains* ("Filter Tasks" tab).
3b. If you got a parametric EQ, click on *Optimize Gains, Qs and Frequencies. *
4. Reset "Speaker Type" to whatever setting it was before.
5. Open "EQ Filter" window. Set your crossovers settings as they were before in the "manual" filter slots and sort the list after frequency. (See picture below)









Now, just enter the values in your DSP. Repeat for each side/individual speaker (depending on how powerful your DSP is).

That's about it ^^

Highres pictures: REW GUIDE Slideshow by Hanatsu2 | Photobucket


----------



## Hanatsu

emoon3 said:


> Subbing to a great thread. I have one question. Is it necessary to have Bruce Willis do the calibration?


lol ^


----------



## spaceace60

i soo wana understand all this! and im a professional guitarist been doin audio(self/friends)for over 25yrs!! this all kinda makes me feel stupid lol!(as i also have good ear and have been a sound man for bands ect ect!!) sooo much more i obviously need to learn and wana learn thanks for posts like this!!


----------



## themad

Long time lurker here.

Hanatsu, thank you for the excellent writeup!

This weekend I was playing with REW and its auto-EQing functionality and was wondering how to set the filters to match the Helix DSP EQ. The standard ones from REW generate a lot of overlap on the frequencies which is not possible due to Helix DSP restrictions.
And for my surprise, when I open my email this morning I read this excellent tutorial from you!


----------



## Hanatsu

themad said:


> Long time lurker here.
> 
> Hanatsu, thank you for the excellent writeup!
> 
> This weekend I was playing with REW and its auto-EQing functionality and was wondering how to set the filters to match the Helix DSP EQ. The standard ones from REW generate a lot of overlap on the frequencies which is not possible due to Helix DSP restrictions.
> And for my surprise, when I open my email this morning I read this excellent tutorial from you!


I'm aware of that little issue. If you use the 1/3oct spaced filters I provided and generate EQ filters with 'Optimize Frequencies, Gain, Qs' instead of full auto it will generate filters that's at 10% +/- of the 1/3oct standard octave spacing which the Helix handles fine


----------



## subterFUSE

I have been wondering how to determine what the "Q" is on the 31 band EQ in the Audison BitOne? I know the Q is the same for all of the bands because it's not parametric, but I've never known what number to use as the Q when using REW to build filters.


This is just for curiosity, however. I'm about to install an Arc Audio PS8 soon, and that has fully adjustable parametric EQ. I will be able to just hit the button in REW and then copy the Auto EQ filter Freq, Gain and Q directly into the DSP.


----------



## themad

Hanatsu said:


> I'm aware of that little issue. If you use the 1/3oct spaced filters I provided and generate EQ filters with 'Optimize Frequencies, Gain, Qs' instead of full auto it will generate filters that's at 10% +/- of the 1/3oct standard octave spacing which the Helix handles fine


Yes, works beautifully! 

Only thing I have to adjust is my 2-way is passive. So, no LP/HP filters from midbass to tweeter. But their transition is great, even stock!
Works the same way though, I use the REW filters you provided but when loading into the Helix DSP I just ignore the duplicated filters (high freqs of midbass -> low freqs of tweeter).

Just compiled all 5 parts to start my tuning from scratch. It's gonna be long hours of fun. :laugh:

Thanks again for all this info!


----------



## venki7744

venki7744 said:


> Hey Hanatsu,
> 
> * How do we go about deciding the target response (59db as shown in step 6 here:http://www.diymobileaudio.com/forum/2105035-post45.html)
> * How do we go about deciding the target crossover point (65db) and does REW set the electrical crossover automatically.
> 
> Sorry for the noob questions.
> 
> Cheers,
> Venki


Hey Hanatsu,

Can you please answer my noob queries.

Thanks,
Venki


----------



## Hanatsu

subterFUSE said:


> I have been wondering how to determine what the "Q" is on the 31 band EQ in the Audison BitOne? I know the Q is the same for all of the bands because it's not parametric, but I've never known what number to use as the Q when using REW to build filters.
> 
> 
> This is just for curiosity, however. I'm about to install an Arc Audio PS8 soon, and that has fully adjustable parametric EQ. I will be able to just hit the button in REW and then copy the Auto EQ filter Freq, Gain and Q directly into the DSP.


Graphic EQ normally uses a Q of 4,31


----------



## Hanatsu

venki7744 said:


> Hey Hanatsu,
> 
> Bumping up this thread to remind you the we are waiting anxiously for the next part ...I have been reading..re-reading...re-reading this thread again and again and I still have some questions:
> 
> * How do we go about deciding the target response (59db as shown in step 6 here:http://www.diymobileaudio.com/forum/2105035-post45.html)
> * How do we go about deciding the target crossover point (65db) and does REW set the electrical crossover automatically.
> 
> Sorry for the noob questions.
> 
> Cheers,
> Venki


*The target level is just an arbitrary number. It's dependent on the measurement settings, input level etc etc. What's important is that you use the same target level when setting EQ for different drivers/measurements, otherwise the house curve will be off.

*REW does not set any crossovers automatically, deciding what crossovers to use is really dependent on what setup you use/what drivers you use. ErinH made a good thread on how to choose xover points;

http://www.diymobileaudio.com/forum/2107539-post11.html

All levels in the guide are arbitrary, they only matter when you relate them to other measurements.


----------



## squeak9798

I can't get REW and my MS8 to play nice, figured this was the best place to ask.

First, no matter what I did I got an error in REW that the output was too low. I however had the volume set as high as it could go without grenading my speakers because the MS8 was allowing the speakers to play a full range tone even though I have them set to highpass at 80hz 24db slope. I even set REW to play a band passed signal 20hz - 25hz and my front speakers crackled the entire time trying to play the tone. On top of that I don't think REW was actually measuring my system because my measurement was identical with the MS8s processing set on or off...so REW was telling me the MS8 was doing nothing at all to the signal. 

I can't figure out why the fronts are playing a 20hz tone thru the MS8. It plays music fine, but let's the fronts play full range from REW. I can't turn the system level up until I figure out how to solve that problem. And I'm not sure if the system level will help the fact REW wasn't actually measuring my system until I can fix the first 2 issues.


----------



## squeak9798

I can't get REW and my MS8 to play nice, figured this was the best place to ask.

First, no matter what I did I got an error in REW that the output was too low. I however had the volume set as high as it could go without grenading my front speakers because the MS8 was allowing the speakers to play a full range tone even though I have them set to highpass at 80hz 24db slope. I even set REW to play a band passed signal 20hz - 25hz and my front speakers crackled the entire time trying to play the tone. On top of that I don't think REW was actually measuring my system because my measurement was identical with the MS8s processing set on or off...so REW was telling me the MS8 was doing nothing at all to the signal. 

I can't figure out why the fronts are playing a 20hz tone thru the MS8. It plays music fine, but let's the fronts play full range from REW. I can't turn the system level up until I figure out how to solve that problem. And I'm not sure if the system level will help the fact REW wasn't actually measuring my system until I can fix the first 2 issues.


----------



## subterFUSE

squeak9798 said:


> I can't get REW and my MS8 to play nice, figured this was the best place to ask.
> 
> First, no matter what I did I got an error in REW that the output was too low. I however had the volume set as high as it could go without grenading my speakers because the MS8 was allowing the speakers to play a full range tone even though I have them set to highpass at 80hz 24db slope. I even set REW to play a band passed signal 20hz - 25hz and my front speakers crackled the entire time trying to play the tone. On top of that I don't think REW was actually measuring my system because my measurement was identical with the MS8s processing set on or off...so REW was telling me the MS8 was doing nothing at all to the signal.
> 
> I can't figure out why the fronts are playing a 20hz tone thru the MS8. It plays music fine, but let's the fronts play full range from REW. I can't turn the system level up until I figure out how to solve that problem. And I'm not sure if the system level will help the fact REW wasn't actually measuring my system until I can fix the first 2 issues.


There could be a few reasons why you are getting low level errors:

One reason could be that you are using a mic that requires phantom power, but you don't have phantom power on your sound card.

What kind of mic are you using with REW?


Another possible reason is that you need to increase the input gain on your sound card for the mic input. REW has level meters and a Check Levels button in the measurement window to allow you to check it.

You shouldn't need to blast your car stereo volume to get good measurements.


----------



## squeak9798

Using the Dayton EMM6 with Mobile pre, using phantom power. Level control on the mobile pre was turned up to just below the clipping point. I did let it clip just to try to get output, and then the system would hum and continue playing the sweep even after REW quit measuring (I'd have to unplug the mobile pre to get it to stop). No matter what I did, still got the same error. Was playing loud enough that 10' behind the car with the door open the sweep was clearly audible. Definitely loud enough the mic should have picked it up but apparently was not. 

Also doesn't explain why my front speakers were playing 20hz at full power with a 80hz 24db highpass.


----------



## Hanatsu

squeak9798 said:


> Using the Dayton EMM6 with Mobile pre, using phantom power. Level control on the mobile pre was turned up to just below the clipping point. I did let it clip just to try to get output, and then the system would hum and continue playing the sweep even after REW quit measuring (I'd have to unplug the mobile pre to get it to stop). No matter what I did, still got the same error. Was playing loud enough that 10' behind the car with the door open the sweep was clearly audible. Definitely loud enough the mic should have picked it up but apparently was not.
> 
> Also doesn't explain why my front speakers were playing 20hz at full power with a 80hz 24db highpass.


It's a soundcard/preamp or mic issue. Do you use ASIO or Java driver in the audio settings? Use ASIO if available and max the buffer.


----------



## subterFUSE

squeak9798 said:


> Using the Dayton EMM6 with Mobile pre, using phantom power. Level control on the mobile pre was turned up to just below the clipping point. I did let it clip just to try to get output, and then the system would hum and continue playing the sweep even after REW quit measuring (I'd have to unplug the mobile pre to get it to stop). No matter what I did, still got the same error. Was playing loud enough that 10' behind the car with the door open the sweep was clearly audible. Definitely loud enough the mic should have picked it up but apparently was not.
> 
> Also doesn't explain why my front speakers were playing 20hz at full power with a 80hz 24db highpass.



Hmmm.... Well, I'm not sure about the levels then.


As for the hum, is your computer connected to wall power when you measure? Sometimes you have to disconnect the power and run on laptop battery to get rid of the ground loop. I must do this on my MacBook Pro with M-Audio M-Track soundcard.


----------



## squeak9798

When I plug it into my car system thru the MS8 as an aux in the sweep isn't actually a sweep, more like just a bunch of crackling. When I plug it in to my garage stereo as an aux in it sweeps just fine. I can't unplug the laptop from the wall because the battery doesn't hold a charge. The only thing I can think of is a ground issue that would cause it to **** up connected to the car but not the garage radio.

Any ideas?


----------



## squeak9798

Well I apparently had two unrelated problems. I had another chance to play around with it today. 

When I use the normal inputs instead of the aux inputs on the MS8 the system will play the tone just fine. When I use input 2 on my mobilepre for the mic instead of input 1 the level reads fine. Pisses me off that I could be done right now instead of just starting, but glad I finally got it to work.


----------



## Hanatsu

squeak9798 said:


> Well I apparently had two unrelated problems. I had another chance to play around with it today.
> 
> When I use the normal inputs instead of the aux inputs on the MS8 the system will play the tone just fine. When I use input 2 on my mobilepre for the mic instead of input 1 the level reads fine. Pisses me off that I could be done right now instead of just starting, but glad I finally got it to work.


Good that you sorted it out... driver issues can be a hassle.


----------



## nickt

Please show me steps on how to make my Arc PS8 as the output device. Thank you.


----------



## nickt

Does the PS8 have be plugged into the computer so it can see it?


----------



## Jazz80

[/URL]N[/IMG]

Need help to see my system. I see the gap from 200-600 Hz. is that because of gain or what? this is is 2 way, active system.
HU : Pioneer P80RS
Tweeter using. Hi-vi swan
Mid : AP
Sub : Morel Primo
Sub : LPF 80 Hz 24db
Mid : 60-3khz
Tweeter :3Khz Hpf.


----------



## Hanatsu

Is that driver side (yellow)? Are the mids low in doors? Do you got a large center console?

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Jazz80

Yes, I have console. The yellow is driver side. I put my mid in the door. I try to generate and match target with generic house curve the result is very poor in midhigh to high freq. thx


----------



## Hanatsu

There's your problem then. It's a cancellation due to mid placement (most likely). Bring down the other side to match better and boost the driver side by max 2-3dB to see if you can balance it out a bit. 

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## sqnut

Jazz80 said:


> [/URL]N[/IMG]
> 
> Need help to see my system. I see the gap from 200-600 Hz. is that because of gain or what? this is is 2 way, active system.
> HU : Pioneer P80RS
> Tweeter using. Hi-vi swan
> Mid : AP
> Sub : Morel Primo
> Sub : LPF 80 Hz 24db
> Mid : 60-3khz
> Tweeter :3Khz Hpf.



How have you set the eq? Add these cuts to whatever you have already applied.

Far side is 10db louder between 200-500. 1.25-3khz needs to be pulled down. Cut both sides at 1.25 by -2db, 2khz by -3db and 3 khz by -4db. Cut far side -4db at 200 and 300hz, raise near side by 1 db. 

Cut near mid by 4db at 80 and 2 db at 100 cut the far side -2db at 80 and -1db at 100. How does it sound?


----------



## Jazz80

Ok I will try tomorrow and let you know how's the result. Almost midnight here. Hehehe.
Thanks for the support


----------



## Roper215

This is my RTA curve with Pink Noise using a calibration file on my UMIK-1.

I am in the process of pulling my headunit to generate the curves based on the sound card sine sweep, until then this is the best I can do.

This curve sounds very bright and very harsh, female vocals specifically. Can anyone shed some light on this for me? 

Thank you,

-Roper215


----------



## JVD240

Roper,

Please apply 1/3 octave smoothing and post that image.


----------



## Roper215

I tweaked it slightly, and its less harsh, some of the bass frequencies are still "honky", but its closer.

I supposed I need to decrease the 20hz and 20khz band several db. Outside of that, it looks like it is about as good as it will get until I can feed sine sweeps into the system via REW.

Any advice would be greatly appreciated. PS I'm not new to car audio, I am very new to "proper tuning" especially in a scientific type manner. 

Thanks,

-Roper215


----------



## tulse

Will the mic and calibration file (.omm) from the Dayton OmniMic work with this?

Edit: Tried it. REW did accept the .omm calibration file that comes with the Dayton Omnimic. I assume the file is doing its job.


----------



## abusiveDAD

Thanks Hanatsu.... apprecited


----------



## JVD240

Roper215 said:


> I tweaked it slightly, and its less harsh, some of the bass frequencies are still "honky", but its closer.
> 
> I supposed I need to decrease the 20hz and 20khz band several db. Outside of that, it looks like it is about as good as it will get until I can feed sine sweeps into the system via REW.
> 
> Any advice would be greatly appreciated. PS I'm not new to car audio, I am very new to "proper tuning" especially in a scientific type manner.
> 
> Thanks,
> 
> -Roper215


Sorry Roper. Meant to say 1/6 oct in my last post.

What HU or DSP are you using?

You can dial things in pretty well with just pink noise and RTA.


----------



## Roper215

JVD240 said:


> Sorry Roper. Meant to say 1/6 oct in my last post.
> 
> What HU or DSP are you using?
> 
> You can dial things in pretty well with just pink noise and RTA.


Alpine ILX-007 and Helix DSP.

I can adjust to 1/6 tomorrow when I fiddle with it some more and repost then.

Also, what frequencies do I want to "bump" up a few db as my midbass response is impacted once the car is in motion?


----------



## Beckerson1

One major question here about mic placement while measuring. Which orientation is the mic. 

I'm sure others have this issue but with my headrest it's virtually impossible to have the mic face forward and hit every one of those points. Now I know there are mics out there that are omni directional and if one has one of those they should be able to measure just fine with the mic pointing up.

I do 4 sweeps right ear, 4 sweeps left ear, and 4 sweeps nose (mic facing up for this one) then average of those is used as the average response.


----------



## Roper215

I'm sure I will take some heat for this, but I am tuning to the middle of the car, it won't sound as perfect as it could, but I do have passengers in my car on a fairly regular basis and I don't want it to sound like garbage to them.

I am just learning the software and how-to, that was a single measurement, and it was taken with the mic inboard on the headrest, so I suppose I'm actually tuning it for my right ear.


----------



## Hanatsu

Don't tune in the middle of the car. Rather measure at each seat and average them together in RoomEQ. Furthermore, the curve might need adjustment. 20-80Hz should be 10-20dB higher than 200-1kHz (this range can be fairly flat), from 1kHz and up you can use a falling slope as you got there.

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Roper215

How do you save the graphs to "average" them afterwards?


----------



## Babs

Roper215 said:


> How do you save the graphs to "average" them afterwards?


Post #11 I believe


----------



## Roper215

Babs said:


> Post #11 I believe


I do not have those options as I am not hooked in via aux input? My measurement ability is impacted.

What can I do to resolve this other than hook up aux input?

Edit: I am in the process of updating to 5.1, I will see if that fixes my problem.


----------



## Hanatsu

"All SPL" tab. Left lower corner. You must also select multiple measurements below the plot window.

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## Roper215

Hanatsu said:


> Don't tune in the middle of the car. Rather measure at each seat and average them together in RoomEQ. Furthermore, the curve might need adjustment. 20-80Hz should be 10-20dB higher than 200-1kHz (this range can be fairly flat), from 1kHz and up you can use a falling slope as you got there.
> 
> Sent from my Samsung Galaxy S5 using Tapatalk


How am I going to get 10 to 20 db out of that area? I can adjust the gain some but 10 to 20 dbs worth?


----------



## bigbubba

Marked this as well as Erin's "How to" thread.


----------



## Roper215

I worked through mic location.


----------



## Roper215

Hanatsu said:


> "All SPL" tab. Left lower corner. You must also select multiple measurements below the plot window.
> 
> Sent from my Samsung Galaxy S5 using Tapatalk


I still don't think I have those options if using the RTA instead of the Measurement function.


----------



## Hanatsu

Roper215 said:


> I still don't think I have those options if using the RTA instead of the Measurement function.


Yes it should still be there, have used this very function myself. Using the latest beta version? Have you selected multiple measurements below the plot in the "All SPL" tab?

I can post an example later or you can perhaps share your .mdat file so I can see what could be the issue.

Sent from my Samsung Galaxy S5 using Tapatalk


----------



## JVD240

Yep, you'll still have it. Just used it tonight.


----------



## Roper215

Hanatsu said:


> Yes it should still be there, have used this very function myself. Using the latest beta version? Have you selected multiple measurements below the plot in the "All SPL" tab?
> 
> I can post an example later or you can perhaps share your .mdat file so I can see what could be the issue.
> 
> Sent from my Samsung Galaxy S5 using Tapatalk


Yes please post an example, I am using 5.10.


----------



## Hanatsu

Roper215 said:


> Yes please post an example, I am using 5.10.




This was done with the "RTA" function.


----------



## Roper215

So this is done after you have multiple graphs 'saved'?

I was not aware of that being the method for gettting this.

I'm running this on a windows tablet, could this be causing issues?


----------



## Hanatsu

Roper215 said:


> So this is done after you have multiple graphs 'saved'?
> 
> I was not aware of that being the method for gettting this.
> 
> I'm running this on a windows tablet, could this be causing issues?


Yes. No issues with tablets as I far as I know.


----------



## Roper215

I'm really not dumb... I know thats hard to believe based on my questions... anyway. 

So, place the mic, play some pink noise and hit save.
Move the mic to another location and repeat.

Do this in multiple places, around 8 times or so.

Aggregate the data/average it, smooth it and post the image up here?

Tune to that image I assume?


----------



## Hanatsu

Roper215 said:


> I'm really not dumb... I know thats hard to believe based on my questions... anyway.
> 
> So, place the mic, play some pink noise and hit save.
> Move the mic to another location and repeat.
> 
> Do this in multiple places, around 8 times or so.
> 
> Aggregate the data/average it, smooth it and post the image up here?
> 
> Tune to that image I assume?


Never assumed you were... I'm just making sure I'm not misinterpreted - it tends to happen anyway :<

Using RTA you can do the averaging during the measurement if you choose to do it that way. Use infinite averaging in the RTA settings and move the mic around your ear (corresponding to the side you're measuring). Measure and move the mic till the graph settles. After that, save it. Repeat for the other side. Finally, overlay both graphs and compare them against each other (post it here if you will). Make sure scaling is correct, 20-20kHz and with 5dB visible vertical resolution.


----------



## Roper215

I'm a total noob to this, and not knowing makes me feel dumb. Anyway.



Is my averaged graph based on the information, not sure if I got the 5 db piece in there or not, I didn't do this at a "loud" volume.

Only around 80 dbs.


----------



## Hanatsu

Volume doesn't matter much unless you got lots of external noise that affects results.

I'd lower the 200-400Hz range by 10dB to begin with. What DSP/EQ do u got?

Sent from my Samsung Galaxy S5 using Tapatalk


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## ben54b

Subd 


Sent from my iPhone using Tapatalk


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## Roper215

Hanatsu said:


> Volume doesn't matter much unless you got lots of external noise that affects results.
> 
> I'd lower the 200-400Hz range by 10dB to begin with. What DSP/EQ do u got?
> 
> Sent from my Samsung Galaxy S5 using Tapatalk


Alpine ILX-007 Source Unit
Helix DSP (regular not pro)
Arc Audio XDI v2 1200.6
HAT Legatia L3v2 Mid Range
HAT Clarus C612 Mid Bass
HAT Clarud 12 Sub
No rears
My build is in my sig


----------



## Hanatsu

Ah. Same DSP as me then, it's a great unit. 

First off, is that the combined response you posted? You should make one for left and right side individually. 

Make EQ these EQ filters;

250Hz Q2 -7dB
400Hz Q2 -5dB

See if the lower midrange sounds less 'muddy'. The slope beyond 1kHz looks a bit steep. An overall level boost of 5dB between 3-15kHz would probably "lighten" the tonality a bit.

Sent from my Samsung Galaxy S5 using Tapatalk


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## Roper215

Yes it was a combined curve.

I can take different measurements for each and will post both images sometime today for them.

Average of 6 to 8 curves per side should be adequate?

I will adjust the frequencies you recommended, the biggest thing my system is "lacking" right now, is the impact of the low end sub.

I'm also somewhat concerned with the overall "loudness" of the system.

In previous systems my litmus test was to turn it up to loud listening volumes and then try to talk to my passenger. If we couldn't hear each other then it was "loud" enough.

I'm not getting that from this one at all. Have I set something incorrectly?


----------



## Babs

Roper215 said:


> Alpine ILX-007 Source Unit
> 
> Helix DSP (regular not pro)
> 
> Arc Audio XDI v2 1200.6
> 
> HAT Legatia L3v2 Mid Range
> 
> HAT Clarus C612 Mid Bass
> 
> HAT Clarud 12 Sub
> 
> No rears
> 
> My build is in my sig



Nice gear. Not to derail but how's the ILX-007 playing well with the DSP. Clean and strong?


----------



## Roper215

I was worried about the 2v preamp out too. I have not detected any noise in the system once the gains were set properly :surprised:.

I'm sitting around -7 to -9 on the output for my front channels as it stands bc of the sub, I'm not sure what my issue is with it. I checked the gain and it seems valid. I'm going to try a pure tone/DMM method again in a day or so once I feel like unbolting the seat again.

Just so I'm correct, it's a dual 2 ohm, for a total of 4 ohm, at 600 watts.. or 2400^.5 or ~48 volts... please correct me if I'm wrong.

I have done some research, and unless you are really looking to compete, 2v is strong enough and keeps the noise out.

I used WestCo RCAs and was very particular about how the wires were run.

I'm grounding the DSP back to the headunit harness which I was told was a good idea, and the amp ground only comes near the power wire around 2 inches before they terminate.

Short answer, no problems what so ever. The headunit is way over priced though, but its cool. The capacitive screen is really really nice, and it was the only unit I could find where I could hardwire spotify to it. AppRadio Pioneer units are actually over Bluetooth, and Kenwood is on my list to never buy from again.


----------



## Hanatsu

Roper215 said:


> Yes it was a combined curve.
> 
> I can take different measurements for each and will post both images sometime today for them.
> 
> Average of 6 to 8 curves per side should be adequate?
> 
> I will adjust the frequencies you recommended, the biggest thing my system is "lacking" right now, is the impact of the low end sub.
> 
> I'm also somewhat concerned with the overall "loudness" of the system.
> 
> In previous systems my litmus test was to turn it up to loud listening volumes and then try to talk to my passenger. If we couldn't hear each other then it was "loud" enough.
> 
> I'm not getting that from this one at all. Have I set something incorrectly?


Yes, 6-8 points/side are adequate. The impact will be more pronounced once the FR curve is more balanced. If you max out the volume on your headunit and it's not loud enough, then you either have too little power available or the gains incorrectly set.


----------



## Hanatsu

Roper215 said:


> I was worried about the 2v preamp out too. I have not detected any noise in the system once the gains were set properly :surprised:.
> 
> I'm sitting around -7 to -9 on the output for my front channels as it stands bc of the sub, I'm not sure what my issue is with it. I checked the gain and it seems valid. I'm going to try a pure tone/DMM method again in a day or so once I feel like unbolting the seat again.
> 
> Just so I'm correct, it's a dual 2 ohm, for a total of 4 ohm, at 600 watts.. or 2400^.5 or ~48 volts... please correct me if I'm wrong.
> 
> I have done some research, and unless you are really looking to compete, 2v is strong enough and keeps the noise out.
> 
> I used WestCo RCAs and was very particular about how the wires were run.
> 
> I'm grounding the DSP back to the headunit harness which I was told was a good idea, and the amp ground only comes near the power wire around 2 inches before they terminate.
> 
> Short answer, no problems what so ever. The headunit is way over priced though, but its cool. The capacitive screen is really really nice, and it was the only unit I could find where I could hardwire spotify to it. AppRadio Pioneer units are actually over Bluetooth, and Kenwood is on my list to never buy from again.


If you got a 4ohm load and 600W then the output should be 48-49V, yes. You can easily set gains with a -10dBFS tone, normal music do not reach 0dBFS.


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## Roper215

thats my problem, I didn't use a -10 db tone.

I will verify and adjust.

Also, I have always been told that a pure tone towards the lower end of the crossovers should be used as these tones are more energy intensive for a given db.

Can you confirm this?


----------



## Roper215

Hanatsu said:


> Yes, 6-8 points/side are adequate. The impact will be more pronounced once the FR curve is more balanced. If you max out the volume on your headunit and it's not loud enough, then you either have too little power available or the gains incorrectly set.


Should I break apart all of the speakers with 6 to 8 measurements each?

Average the left and right seperately, then bring in the sub to have 1 averaged curve for all 5 speakers, overlayed ontop of 5 other curves?


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## Hanatsu

Roper215 said:


> thats my problem, I didn't use a -10 db tone.
> 
> I will verify and adjust.
> 
> Also, I have always been told that a pure tone towards the lower end of the crossovers should be used as these tones are more energy intensive for a given db.
> 
> Can you confirm this?


No. You can use any frequency as long as they are amplified equally. I use 1kHz for fullrange and 50Hz for sub amps because some of them got lowpass filters built in. 

_Once you add EQ the "power requirement profile" is altered anyway. To get the most out of your system you could take the most inefficient speaker in your system, check where the output is at its highest point (EQ peak) then set gains at that point. Then all other amps could simply be level matched vs the frequency range of this speaker. But now I'm just being confusing... _


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## Hanatsu

Roper215 said:


> Should I break apart all of the speakers with 6 to 8 measurements each?
> 
> Average the left and right seperately, then bring in the sub to have 1 averaged curve for all 5 speakers, overlayed ontop of 5 other curves?


All speaker could be measured separately to optimize crossovers. 

Left side (all speakers left side playing + sub) = 5 points at around left ear, 3 points around right ear.

Right side (all speakers right side playing + sub) = 6 points at around right ear, 2 points around left ear.

That's how I do it with RoomEQ. I just average the 8 measurements each side in the software as I described earlier.


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## Roper215

Awesome, I'm trying to work through it the best I can as I am learning to use the software and tune the system.

I have subsequently improved the subwoofer greatly.

What I am interested in, what "should" the curve look like, and what db variantions should I be trying to acheive from 20hz to 20khz.

so 20hz to 100hz should all be about flat in terms of dbs, what about 200hz?
-3 or -4 dbs, and then where do you want it to begin to taper again and by how much?

I adjusted my crossovers based on the manufacturers recommendations. I am crossed at 65 to 200 +24 on my mids, 315 HB +24 on my mid range, and 80 LP +24 on my sub.

Ps, what I heard you say was I can post some curves, save my helix file and send it to you and get a better one back


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## Hanatsu

As a starting point the curve should be;

20-80Hz (15-10dB)
80-200Hz (10-0dB)
200-1000 (flat)
1000-20000 (0 to -10dB)

Something like that...

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## Hanatsu

Roper215 said:


> Awesome, I'm trying to work through it the best I can as I am learning to use the software and tune the system.
> 
> I have subsequently improved the subwoofer greatly.
> 
> What I am interested in, what "should" the curve look like, and what db variantions should I be trying to acheive from 20hz to 20khz.
> 
> so 20hz to 100hz should all be about flat in terms of dbs, what about 200hz?
> -3 or -4 dbs, and then where do you want it to begin to taper again and by how much?
> 
> I adjusted my crossovers based on the manufacturers recommendations. I am crossed at 65 to 200 +24 on my mids, 315 HB +24 on my mid range, and 80 LP +24 on my sub.
> 
> Ps, what I heard you say was I can post some curves, save my helix file and send it to you and get a better one back


Send me the *.mdat REW file and helix data file and I can see if I can mod it for you 

Pm me for mail adress.

Sent from my Samsung Galaxy S5 using Tapatalk


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## Roper215

I think I can only safely assume I need to adjust my gains at this point:



The curve isn't too bad if I could bring the mids to highs up 10 to 15 dbs.

I have subsequently turned my sub gain down about 1/8 of a turn as I was getting "sub thump" when I turned off the system which I wasn't getting before I adjusted the gain.

I made a feeble attempt at gain setting with an oscope, and it's been nothing but a big pain in my ass ever since. I should be able to adjust some things over the weekend, I will update afterwards.

Any feedback based on the above graph (6 points on both sides, averaged sub included in all graphs, average of averages (I think x double bar?))


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## Roper215

Help, the highs are ripping my ears off.

Each curve is an average with both left and right at the same time, I'm going to fine tune it per side once I get it closer.

1.6 and 2k, reduce by 3 dbs?

Green = Baseline 1
Blue = Baseline 2

What frequencies do I need to lower, and by how much.


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## Hanatsu

Roper215 said:


> Help, the highs are ripping my ears off.
> 
> Each curve is an average with both left and right at the same time, I'm going to fine tune it per side once I get it closer.
> 
> 1.6 and 2k, reduce by 3 dbs?
> 
> Green = Baseline 1
> Blue = Baseline 2
> 
> What frequencies do I need to lower, and by how much.


First. Fix vertical scaling 

You see the horizontal lines? They are spaced with 20dB in your graph, it needs to be in 5dB spacing in order to be able to read the graph.

Adjust "Limits" in the top right corner till you get this vertical resolution


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## Roper215

Can someone please post a pink noise curve for their system, left, right and combined?

It appears that most of the curves are sine sweep curves, which I cannot do yet.


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## Hanatsu

Dip at 185Hz is not EQable. I think the tilt of the curve looks a bit too heavy. 35dB level difference between lower midbass and highs...

As I understand, you're using fullrange drivers without dedicated tweeters. You can try this; 4,5-20kHz should be about 6-7dB higher. Pull down 1900Hz -5dB Q4.

300-600Hz should be pulled down by 4-5dB. Try a Q1 -4dB at 400Hz. 

Decrease midbass overall level by 5dB.

Decrease sub level by 10dB.

-------

L/R balance looks good. 1 or 2dBs around ~400Hz. I assume green plot is driver side due to the modal dip. 

RTA/Noise and SineSweep produce similar results but depends on how you average of course. The main difference is that you gain access to time domain data as well as non-linear distortion plots with tone sweeps.


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## Roper215

I think its real close now. I didn't take new measurements but I dipped 1,1.25,1.6 and 2k by 1db and decreased the output by 1 db.

Some of the highs for vocals sounded ear piercing and same with the electric guitar.

I also have it slightly bass heavy as when the car is in motion it loses some low end.

What else should I do?


Green: Right
Purple: Left

Other than it being slightly bright, and causing some fatique after listening it sounds pretty good, I just need to address those two trouble spots.


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## Hanatsu

Try this:

Bring down 1800Hz by 8dB, 2500Hz by 4dB, 3500Hz by 3dB, 4000Hz by 4dB.

Also boost right side so it matches left side around 300-1000Hz. Flatten out 400-900Hz slightly (lower it by 2-3dB right side)

Keep 1800-5000Hz relatively flat around "20dB" on your plot.


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## Roper215

Sweet Jesus, it's more or less finally over.



There she is, I adjusted:

2k: -1
6k: -2

Other suggestions are welcome, I think I need to bump up the 30/40hz band a couple, but at this point its subtle tweaks.

I didn't take new mic measurements afterwards, but holy crap does it sound good. I unfortunately cannot eq out the dip at 1.25khz, which semi sucks, but it might be adjustable with Q? Which I really don't understand what it is or how to use it, so... I didn't touch it.

Anyway. I'm pretty happy with it, only took me 5 days and ~30 hours. Anything worth learning is tough right? 

Now to start planning what I'm going to change next... All I can really come up with is to move over to L3SE's... but I'm not sure I would realize much benefit.


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## Hanatsu

Try lowering 2,1kHz slightly with a Q5 band. It might not be an issue, you'll notice pretty quick. Good to hear it sounds better.

Q is the width of the filter. Low Q affects a wide set of frequencies, high Q only affect a narrow band.


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## Roper215

I adjusted a few things today and will post up the left/right/combined curves later today/tomorrow.

30hz +3
40hz+2
125hz -1

I'm going to turn the volume up some for my next go round, I've been tuning at volume 15, and I feel like some of the linear transitions are lost as the volume increases.

I will measure around 20 to 22 this time to see how it's plotting.

I took your advice and adjusted the Q value, and it sounds better, thank you.

Whats the most interesting thing is the way the car sounds when you are in the passengar seat... I think the term is bad.  the stage is shot, as it sounds like everything is coming from the right mid.


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## Hanatsu

Yes. That's to be expected. All my cars sound and stage like crap from passenger seat. I don't care about them xD

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## Roper215

yeah, I'm not overly concerned.

I've got a buddy of mine letting me test some HAT L3SE's as long as I report back out the curves and differences.

I'm curious as to how they will sound.

How do you graph the "difference" curve?


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## Hanatsu

All SPL, "Controls" is the upper right corner. "Trace Arithmetic" then choose two measurements you got loaded. After that choose "A/B" and hit "Generate".


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## crazhorse

Im not sure if I missed it in my reading etc but... Im using a minidsp usb mic and unsure about the calibrating of my soundcard. Since Im using a usb mic and calibrating is using the input/output of the soundcard is calibration needed?


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## ajsmcs

Approximately how long does it take to run a sine sweep?


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## Babs

The time in seconds I believe is adjustable. Slower will have more time through a given bandwidth hence higher resolution of reading.. I guess.

I broke out REW last night first real time doing some measurements. I've got one helluva learning curve to climb out of for sure. As Erin told me.. You just gotta play with it and put in the time infront of it. <-- I hope. Funny I was messing with Helix RTA as well for giggles, it appears to be a right capable tool as well. Certainly not as high-end, but the new tool has a rather cool auto-eq function, I guess like REW.


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## subterFUSE

ajsmcs said:


> Approximately how long does it take to run a sine sweep?



User defined based on sweep range, and desired resolution. Generally about 4-6 seconds.


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## ajsmcs

Ah, ok. 

So it should take maybe 15 mins at most to run all of the sweeps, then? (Which includes the time it takes to reposition the make and get in position)

I'm just wondering if its one of those "Easy to do after work" sorts of projects, or one of those "You better plan a whole weekend" type of things.


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## subterFUSE

ajsmcs said:


> Ah, ok.
> 
> So it should take maybe 15 mins at most to run all of the sweeps, then? (Which includes the time it takes to reposition the make and get in position)
> 
> I'm just wondering if its one of those "Easy to do after work" sorts of projects, or one of those "You better plan a whole weekend" type of things.


Better plan for a few hours. As you get more experienced with taking measurements, the time will become shorter.


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## Babs

Yep, I imagine what will take me hours and hours to learn, the REW pro's knock out in a few minutes, until I get proficient.


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## ajsmcs

After I've EQ'd all of the individual speakers, set gains, crossovers, etc, I'm thinking of performing a second round of sine sweeps.

Only rather than it being on a single speaker basis, it would be all left speakers at once, and all right speakers at once, so I can get the overall frequency response for each side.

My MiniDSP has both input and output PEQ (one on each of the two input channels, one on each of the 4 outputs).

So once the output PEQs are tuned as far as they will go, I'm going to try to repeat the process with the input PEQs to dial it in even further.


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## Babs

I left out one little detail for a few reasons on my install.. No aux port connected behind the head unit. I've got a Helix DSP and remote with volume control. Would it still be kosher to go that route as in post 1, or am I asking for trouble and should pull head unit and add an aux cord to feed head unit sweeps from laptop through head unit?


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## ajsmcs

So here's my experience with this:

It took about 15 minutes to measure all of the speakers. Everything went pretty smoothly with one exception: for some reason, my right tweeter was about 15 louder than everything else.  
Since it was the last one I did, in retrospect I'll chalk it up to accidentally hitting a button between speakers.


It took a lot of going back and forth to this How-To to get a feel for how everything works. Once I got the hang of it, I level matched everything in the software, and copied that over to MiniDSP. Then I ran the AutoEQ on everything. Weird bug I had, though, was that it would delete my HPF and LPF settings whenever I hit the Optimize button. Went out to the car, synced the MiniDSP, and...


It really sucked. I can't express in words just how much it sucked. There was almost no treble. It was dull, lifeless, and imaging was nonexistent. I knew I did something weird, but I wasn't sure what.


When I got into my car this morning, I went to reach into my glovebox to get something. That's when that I realized that I could barely hear my right tweeter.


I had gained it way down to match the response in the software, and this is the point where I realized I had screwed something up along the way. So I pulled out my phone RTA, turned off both woofer, and compared my tweeters with Left Only/ Right Only pink noise.

Sure enough, the right tweeter was about 15 decibels too low. I then fixed it, and it sounded way better. But still not *perfect.*

So I started playing around with REW during my lunch break, and went and manually set all of the EQ frequencies, levels, etc, to match the target curve, and got them to be pretty darn exact.


Went back out to the car, synced the MiniDSP again, and cued up Radiohead's "Subterranean Homesick Alien," which is one of my test songs.


I normally don't like to be hyperbolic, but the experience I had was *absolutely transcendental.* It was like hearing the song for the first time. 

It was - no joke - like having _*sex*_ for the first time.

And it was _definitely_ that point where all of the time, energy, and money I spent on what I have felt really, truly *worth it.*

Thank you, *Hanatsu*, for taking the time to teach us all how use this wonderful piece of software.


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## ajsmcs

As I mentioned before, I'm still going to go back and redo the process, measuring each side as a single unit, and adjusting the final responses using the Input PEQ on my MiniDSP.

Just for kicks, I may even go back a third time to measure the entire system together, and tuning the final response using the 8 band GEQ on my headunit.

But so far it's beyond what I could've ever imagined.


----------



## Extended Power

Bookmarked!


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## ajsmcs

Well, after the initial honeymoon phase of the first attempt at tuning, I've remeasured the system at least twice more, and it has sounded better with each subsequent attempt.

I keep having this weird problem, though. For some reason some speakers will measure far louder than others, but not how they're supposed to. I had balance zeroed, all processing turned off, and only the speaker being measured turned on. I ran the sine sweeps, and somehow the RIGHT sound played much louder than the left. At first I assumed it was just the nature of manufacturing that one speaker is slightly louder.

But after level-matching within the software, and carrying those settings over to my DSP, I found that the right sound was far too quiet by an extreme degree. I then double checked each speaker with an RTA with processing off, and as expected - the left side, not the right side, was louder, as it should be.

So somehow the signal to the left side is being attenuated. An earlier attempt had everything about the same level except the right tweeter, which played way louder.

I'm using the Dayton iMM6 with my Microsoft Surface, which uses the Apple style TRRS headphone jack.

Could that be whats causing me problems?


----------



## Roper215

Didn't read your entire post, removed after I read your entire post.


----------



## subterFUSE

ajsmcs said:


> Well, after the initial honeymoon phase of the first attempt at tuning, I've remeasured the system at least twice more, and it has sounded better with each subsequent attempt.
> 
> I keep having this weird problem, though. For some reason some speakers will measure far louder than others, but not how they're supposed to. I had balance zeroed, all processing turned off, and only the speaker being measured turned on. I ran the sine sweeps, and somehow the RIGHT sound played much louder than the left. At first I assumed it was just the nature of manufacturing that one speaker is slightly louder.
> 
> But after level-matching within the software, and carrying those settings over to my DSP, I found that the right sound was far too quiet by an extreme degree. I then double checked each speaker with an RTA with processing off, and as expected - the left side, not the right side, was louder, as it should be.
> 
> So somehow the signal to the left side is being attenuated. An earlier attempt had everything about the same level except the right tweeter, which played way louder.
> 
> I'm using the Dayton iMM6 with my Microsoft Surface, which uses the Apple style TRRS headphone jack.
> 
> Could that be whats causing me problems?



The output from REW is single channel mono.

On my car I have to run a Y cable from the computer output and then use both the left and right RCA inputs on my head unit. Otherwise I get the same issue.


Sent from my iPhone using Tapatalk


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## Babs

What if maybe mono cable from laptop output?

subterFUSE! Man with the plan.. Baddest Audi I ever sat my butt in.. And I sold them for Pete's sake. 


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## Babs

Just a note for you guys.. Appears our distinguished Op has a continuing thread going. 
I remembered stumbling on it and hunted it down again to share here for continuing the learning journey. 
Might not be intended for the threads to be linear, or possibly parallel with each other. 

http://www.diymobileaudio.com/forum...bers/174268-how-get-most-out-your-system.html


----------



## Mike Bober

Ive been having an issue getting my Infinite Baffle subs to play well above 45 hz, and im guessing that it could possibly be because i have a 1 1/2" pvc tube running from trunk into the cabin of my car. I will try to fill the end with silicone to seal it off when the weather breaks again, but i would like to know if this is what can cause them dropping off above 45 hz like this. They are two 15" type R subs and in this photo i actually had them x-overed at 110 hz @ 24db. But no matter what i set the x-over at nothing changes in the measurements from REW. Thanks


----------



## dannyboy100

So I finally had some time to give this a go. I was able to get through the whole process outlined by Hanatsu (awesome write up, very helpful!). 

After I was done I can say my system sounds better than it ever has!! But I feel theres room for improvement, which can be chalked up to user error!! 

So with that said I had some questions I'm hoping one of you guys can clear up for me.

Everything was pretty smooth up until I set the levels for each pair of drivers.
I got a little confused after that.

When we set the eq and xovers, which scaling do we use on each driver?
Do we still use 1/1 for all drivers, like we did when setting the levels?

Also,

Since REW is resetting the xover info when loading the EQ filters, is it necessary to manually choose the acoustic xovers points, eq and then enter those same values again?

Or, do we EQ first then look for the best acoustic xover points based on the curve after we run auto eq?

I noticed when I do it the way it was written ( find xovers points first run eq and then re-enter the same points) the graph doesnt really match the target curve as well as it did before I ran auto EQ. I can however, find a different acoustic xover point after the EQ that better matches the curve.

I hope this makes sense!!


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## crackinhedz

Hanatsu said:


> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


Curious since I do have a charger,

Amazon.com: Schumacher SC-1200A/CA SpeedCharge 3/6/12 Amp Charger/Maintainer/Tester: Automotive


So it is ok to have the charger connected while the battery is still connected to the car? Do I just use ACC and not actually turn the car on?

Just afraid of frying something. :blush:



Also, I am using REW on a CarPC via Optical to a DSP and using a Dayton USB Mic...am I able to measure Impulse response (it gives me an Impulse result, but is it accurate?) or do I still need an external soundcard using an analog Mic for this?


----------



## subterFUSE

crackinhedz said:


> Curious since I do have a charger,
> 
> 
> 
> Amazon.com: Schumacher SC-1200A/CA SpeedCharge 3/6/12 Amp Charger/Maintainer/Tester: Automotive
> 
> 
> 
> 
> 
> So it is ok to have the charger connected while the battery is still connected to the car? Do I just use ACC and not actually turn the car on?
> 
> 
> 
> Just afraid of frying something. :blush:
> 
> 
> 
> 
> 
> 
> 
> Also, I am using REW on a CarPC via Optical to a DSP and using a Dayton USB Mic...am I able to measure Impulse response (it gives me an Impulse result, but is it accurate?) or do I still need an external soundcard using an analog Mic for this?



REW will not give time domain data with a USB mic. Only frequency response. You can still get a lot accomplished with a USB mic, but can't measure for time alignment or phase.

To get time data, you need an XLR mic and a sound card with 2 inputs and 2 outputs. One output is looped back into the sound card for time reference.


Sent from my iPhone using Tapatalk


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## Beckerson1

crackinhedz said:


> Curious since I do have a charger,
> 
> Amazon.com: Schumacher SC-1200A/CA SpeedCharge 3/6/12 Amp Charger/Maintainer/Tester: Automotive
> 
> 
> So it is ok to have the charger connected while the battery is still connected to the car? Do I just use ACC and not actually turn the car on?
> 
> Just afraid of frying something. :blush:
> 
> 
> 
> Also, I am using REW on a CarPC via Optical to a DSP and using a Dayton USB Mic...am I able to measure Impulse response (it gives me an Impulse result, but is it accurate?) or do I still need an external soundcard using an analog Mic for this?


Yes car off with charger on battery to supliment power. I've got a 7 amp charger and while tuning I see around 12.5v. Ya not charging but The idea is to relieve some of the demand off the battery.


----------



## crackinhedz

Thanks for the response, good to know. I was hoping that since REW was built into my CarPC that the loop back was being seen from the usb mic, as most people use a laptop to their head unit with need for the additional sound card. Oh well.

Thanks!


----------



## subterFUSE

crackinhedz said:


> Thanks for the response, good to know. I was hoping that since REW was built into my CarPC that the loop back was being seen from the usb mic, as most people use a laptop to their head unit with need for the additional sound card. Oh well.
> 
> Thanks!


It's a software limitation.

HolmImpulse allows for Impulse Response with Timing from a USB mic.
It's just REW that does not.


----------



## crackinhedz

Cool, I'll check out HolmImpulse. Thanks!


----------



## Hanatsu

Glad the thread is still active!

RoomEQ version 5,13 have been released and there's some new functions. I wanted to highlight the new smoothing functions here. Here's from the help file in REW:



> *Apply a smoothing filter to the current channel. Repeating the action removes the smoothing. Variable smoothing applies no smoothing below 100 Hz, 1/3 octave above 10 kHz and varies between 1/48 and 1/3 octave from 100 Hz to 10 kHz, reaching 1/6 octave at 1 kHz. Variable smoothing is recommended for responses that are to be equalised.
> 
> **Psychoacoustic smoothing* uses 1/3 octave below 100Hz, 1/6 octave above 1 kHz and varies from 1/3 octave to 1/6 octave between 100 Hz and 1 kHz. It also applies more weighting to peaks to produce a plot that more closely corresponds to the perceived frequency response.
> 
> *ERB smoothing uses a variable smoothing bandwidth that corresponds to the ear's Equivalent Rectangular Bandwidth, which is (107.77f + 24.673) Hz, where f is in kHz. At low frequencies this gives heavy smoothing, about 1 octave at 50Hz, 1/2 octave at 100 Hz, 1/3 octave at 200 Hz then levelling out to approximately 1/6 octave above 1 kHz.


Variable smoothing is useful for almost every measurement. Psychoacoustic smoothing though, is the interesting thing. It compensates more for how we perceive sound and takes into account the audibility of high Q peaks. It could be very useful when "fine tuning" or troubleshooting overall tonality issues. Keep in mind that when you compensate for the peak in your DSP, use a detailed view like 1/24oct to see how to accurately fix the deviation. This is in other words a smoothing/view mode that allows you to see if the overall shape of the curve is as smooth as you perceive it.


----------



## lizardking

Can't wait to see some measurements......


----------



## subterFUSE

Hanatsu said:


> Glad the thread is still active!
> 
> RoomEQ version 5,13 have been released and there's some new functions. I wanted to highlight the new smoothing functions here. Here's from the help file in REW:
> 
> 
> 
> Variable smoothing is useful for almost every measurement. Psychoacoustic smoothing though, is the interesting thing. It compensates more for how we perceive sound and takes into account the audibility of high Q peaks. It could be very useful when "fine tuning" or troubleshooting overall tonality issues. Keep in mind that when you compensate for the peak in your DSP, use a detailed view like 1/24oct to see how to accurately fix the deviation. This is in other words a smoothing/view mode that allows you to see if the overall shape of the curve is as smooth as you perceive it.





Just an additional note.... John M, the author of REW, suggests only using Variable Smoothing if attempting to use Auto EQ.


----------



## bbfoto

Just a bump to the thread and another BIG THANK YOU to Hanatsu and to all others that have contributed!

Errr...leave it to me to bump a "sticky", LOL.


----------



## DavidRam

This thread has been a great help! Thanks op!


----------



## Ainuke

Hanatsu said:


>


Thanks for the awesome thread!

Re: Bruce Willis.

Since he was unavailable* to take a cast, I had to improvise with Amazon Prime. $9 shipped.

*_And by unavailable, I really mean that the restraining order was still in effect..._


----------



## TwistdInfinity

Ainuke said:


> Thanks for the awesome thread!
> 
> Re: Bruce Willis.
> 
> Since he was unavailable* to take a cast, I had to improvise with Amazon Prime. $9 shipped.
> 
> *_And by unavailable, I really mean that the restraining order was still in effect..._


Hahaha oh man I can't believe what I'm seeing

Sent from my D5833 using Tapatalk


----------



## Ainuke

Hanatsu said:


> *Setup your system, Pt3: Adjust L/R Levels*
> 
> *Step 4b.* Select left/right side measurements for each set of drivers. For example, (left & right midbass) together and (left & right tweeters) together. See picture below. Repeat for each set of drivers.
> 
> View attachment 53638
> 
> _""Picture 3. Zoomed in view. Average level difference, left/right side"_
> 
> *Step 4c.* Make the the necessary changes in your DSP or HU. Lower the side with the loudest overall response by the appropriate amount, in the example above the average level was about 3-4dB too high on the the driver side, YMMV. All DSPs I've seen have a separate level control on each speaker, it's often located in the crossover section of the interface.


Quick question, and forgive if it has been answered please.

If we make the change in the DSP, do we re-measure all the speakers, or is there a way to do it virtually in REW. I see "Measurement Offsets" in the controls tab, but that looks like it just moves the line, or does it decrease the "level" of the signal in REW? Is there another way to bring down the channel's level in REW for the simulation?

-Erik


----------



## Babs

Ainuke said:


> Quick question, and forgive if it has been answered please.
> 
> 
> 
> If we make the change in the DSP, do we re-measure all the speakers, or is there a way to do it virtually in REW. I see "Measurement Offsets" in the controls tab, but that looks like it just moves the line, or does it decrease the "level" of the signal in REW? Is there another way to bring down the channel's level in REW for the simulation?
> 
> 
> 
> -Erik



Erik, good question. REW will show you a predicted freq response from EQ filters applied to a curve which is fairly good. However, you'd want to remeasure to verify the actual after the EQ is actually applied. 

Also keep in mind, if you apply filters to individual drivers, this won't give an accurate baseline of what say a pair or group of drivers together will do because of all the constructive and destructive interaction between those multiple drivers in car which cannot be predicted but only measured when played together. 

Thus I might have spot on beautifully curved smooth responses dialed in on individual drivers, then all bets are off when I measure two left/right mids for example together. 

So from that, I'll approach individual driver EQ to mainly smooth out their wonky response, then work on their balance and centering of stage then combined response with more scrutiny towards a curve or desired outcome response. 

Disclaimer: I'm still learning this as I go and make zero claims of being any kind of expert. 


Sent from iPhone using Tapatalk


----------



## Ainuke

Babs said:


> Erik, good question. REW will show you a predicted freq response from EQ filters applied to a curve which is fairly good. However, you'd want to remeasure to verify the actual after the EQ is actually applied.
> 
> Also keep in mind, if you apply filters to individual drivers, this won't give an accurate baseline of what say a pair or group of drivers together will do because of all the constructive and destructive interaction between those multiple drivers in car which cannot be predicted but only measured when played together.
> 
> Thus I might have spot on beautifully curved smooth responses dialed in on individual drivers, then all bets are off when I measure two left/right mids for example together.
> 
> So from that, I'll approach individual driver EQ to mainly smooth out their wonky response, then work on their balance and centering of stage then combined response with more scrutiny towards a curve or desired outcome response.
> 
> Disclaimer: I'm still learning this as I go and make zero claims of being any kind of expert.
> 
> 
> Sent from iPhone using Tapatalk


Thanks for the response, Babs.
Maybe I'm asking the question the wrong way...

When we're doing the L/R level matching, let's say I drop the L mid by 5db in my DSP. How do I tell REW that I've done that? My FR plots still show the original level, and AutoEq will generate the filters based on that, right?

So do I go into the "Measurement Offset" for that driver and dial in -5db to bring the plot in line? If so, when AutoEq generates the filter, is it accurate to the new level of that driver?

Or do I level match L/R and re-measure it all before EQ so AutoEq gets it right?

I'm mainly asking because when the measurement offset is applied, it doesn't show cumulative changes, so you have to keep track of exactly how much you've added/subtracted.

I get that I need to EQ them as L group and R group (my dsp won't let me EQ the tweets and midbass separately anyway).

-Erik


----------



## Babs

Ah. Ok for level matching, and this is a cool feature in the SPL graph screen to apply an offset to one measurement to match another. 

within a few db is reasonable assumption the response shouldn't change dramatically a few db one way or another so you can assume fine. 

I'd guess your new Auto-EQ work should be reasonably accurate still enough for our purposes. 

However if concerned with EQ of more than one driver but you've changed the level on one of those, all bets are off and you gotta remeasure to be accurate. 


Sent from iPhone using Tapatalk


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## subterFUSE

My technique before Finals was measure, adjust, measure, adjust, measure, adjust, etc...

And each measurement was actually 4 sweeps averaged together from different mic locations. It took a long time, to say the least.


Sent from my iPhone using Tapatalk


----------



## Ainuke

Babs said:


> Ah. Ok for level matching, and this is a cool feature in the SPL graph screen to apply an offset to one measurement to match another.
> 
> within a few db is reasonable assumption the response shouldn't change dramatically a few db one way or another so you can assume fine.
> 
> I'd guess your new Auto-EQ work should be reasonably accurate still enough for our purposes.
> 
> However if concerned with EQ of more than one driver but you've changed the level on one of those, all bets are off and you gotta remeasure to be accurate.
> 
> 
> Sent from iPhone using Tapatalk


Ok, thanks!

I'll use the current readings to set the levels, then re-measure.
I think something's screwy with my data anyway. My mids have no HF rolloff; at about 3k, in fact, the mids seem to catch the tweeter trace and go _up_. Same with the sub data; it rolls off to about 350, then starts climbing along the tweeter trace. Not sure what's going on here... It looks like there was some signal coming through the tweeters for the other drivers, even though I had them muted during the measuring. Or somehow, the signal was feeding back through a crossed connection in the mic/cable (using iMM-6 through a 3ft. extension into a Win8 laptop/tablet). I thought it was odd when I heard the >3k sweep when I was measuring the sub, but chalked it up to my inexperience; all x-overs were disabled, after all...

Thanks for the feedback, guys!
-Erik


----------



## Ainuke

subterFUSE said:


> My technique before Finals was measure, adjust, measure, adjust, measure, adjust, etc...


Wow, that's remarkably similar to my current technique of listen, adjust, listen, adjust, listen, adjust, say "F-IT!" and start from scratch with Imprint. Coda.



-Erik


----------



## Hanatsu

Ainuke said:


> Quick question, and forgive if it has been answered please.
> 
> If we make the change in the DSP, do we re-measure all the speakers, or is there a way to do it virtually in REW. I see "Measurement Offsets" in the controls tab, but that looks like it just moves the line, or does it decrease the "level" of the signal in REW? Is there another way to bring down the channel's level in REW for the simulation?
> 
> -Erik


RoomEQ predicts the outcome. However, if you got only slight phase inconsistencies between speakers or other forms of destructive interference, EQ might not affect the response as you and the software predicts. This is especially true when you try to EQ boost in a modal cancellation.

Offset only moves the "reference level". If you made several measurements and not at the same level you can use this to line them up. It could be used to observe the level of a channel too. For example if you lowered the midrange channel by 3dB you could mess with the offset to see how it would line up against the other channels...

I'd always remeasure after I made some changes to confirm that the FR responds as intended. 

AND BE CAREFUL when doing offsets, IF you apply the change to the selected measurement - that measurement is no longer accurate as long as you don't make the same change in your DSP.


----------



## Babs

Ainuke said:


> Ok, thanks!
> 
> 
> 
> I'll use the current readings to set the levels, then re-measure.
> 
> I think something's screwy with my data anyway. My mids have no HF rolloff; at about 3k, in fact, the mids seem to catch the tweeter trace and go _up_. Same with the sub data; it rolls off to about 350, then starts climbing along the tweeter trace. Not sure what's going on here... It looks like there was some signal coming through the tweeters for the other drivers, even though I had them muted during the measuring. Or somehow, the signal was feeding back through a crossed connection in the mic/cable (using iMM-6 through a 3ft. extension into a Win8 laptop/tablet). I thought it was odd when I heard the >3k sweep when I was measuring the sub, but chalked it up to my inexperience; all x-overs were disabled, after all...
> 
> 
> 
> Thanks for the feedback, guys!
> 
> -Erik



I think the IMM-6 is your problem. I don't think REW and that particular mic play well together. I never could get the IMM-6 to work with it. 

Spring for a sure enough mic such as a UMIK-1 or UMM-6 for a USB mic, or something like a Behringer ECM8000 or Dayton EMM-6 for using an external audio interface. 


Sent from iPhone using Tapatalk


----------



## Ainuke

Babs said:


> I think the IMM-6 is your problem. I don't think REW and that particular mic play well together. I never could get the IMM-6 to work with it.
> 
> Spring for a sure enough mic such as a UMIK-1 or UMM-6 for a USB mic, or something like a Behringer ECM8000 or Dayton EMM-6 for using an external audio interface.
> 
> 
> Sent from iPhone using Tapatalk


After further investigation, it appears that my issue is with the extension cable I'm using on the IMM-6. The laptop I'm using is an Asus 2-in-1 laptop/tablet (never, EVER, buy one of these, BTW) that uses a TRRS jack for audio in/out. Since using the IMM-6 plugged directly into the tablet would bring all kinds of placement & reflection artifacts, I bought a TRRS extension cable so I could just place the mic where needed. I don't know if there's a shielding issue with the cable, or a short of some sort, but even without the mic (just the cable inserted), the signal in REW picks up ~300hz and slopes up in a 45 degree plot to 20k, regardless of output source (even with none plugged in). The same procedure with only the mic inserted yields a proper looking plot for all measured drivers, i.e. no climbing HF slope.

(Wish I could get my desktop PC out to the car for use, as I have a somewhat high-end sound card in it that would make for less hassle measuring).

I would love to get a more specialized mic for measurements, but my budget's been long busted for this. An extra $80-$150 to get it "perfect" isn't in the cards, especially if I want better midbass drivers . 
I have StudioSix audio tools on my iPad/Phone that I'll see if I can get to approximate the REW functions with the IMM-6.

I _do_ appreciate the advice, regardless of my ability to follow it .
Thanks!


----------



## Niick

Babs said:


> Also keep in mind, if you apply filters to individual drivers, this won't give an accurate baseline of what say a pair or group of drivers together will do because of all the constructive and destructive interaction between those multiple drivers in car which cannot be predicted but only measured when played together. .
> 
> Disclaimer: I'm still learning this as I go and make zero claims of being any kind of expert


Hey Babs, let me just say first, that the only reason I'm telling you this (my posts seem to be taken as "arguments" quite often) is because, for me, it was quite the enlightening moment when I first discovered that it actually works.

In truth, there IS software that can predict EXACTLY what the measured response WILL be IF you apply EQ filtering/delay/Xovers to two or more drivers and then play them simultaneously.

The only thing that makes the actual measured response POTENTIALLY differ from the predicted response is if the hardware filters you implement aren't exactly like the simulation's mathematically idealized filters. 

In other words, if you're using analog EQ......or an Audison Bit product. 

I do it all the time at work, it helps me save massive amounts of time when tuning/troubleshooting systems of unknown (and sometimes known) origin. 

When I first found that the measured response could be simulated, and that the simulation was EXACLY the same as the real thing, it really made me totally re-think this whole "too complex of an interaction because of all the reflections" thing.


----------



## Babs

Niick said:


> Hey Babs, let me just say first, that the only reason I'm telling you this (my posts seem to be taken as "arguments" quite often) is because, for me, it was quite the enlightening moment when I first discovered that it actually works.
> 
> In truth, there IS software that can predict EXACTLY what the measured response WILL be IF you apply EQ filtering/delay/Xovers to two or more drivers and then play them simultaneously.
> 
> The only thing that makes the actual measured response POTENTIALLY differ from the predicted response is if the hardware filters you implement aren't exactly like the simulation's mathematically idealized filters.
> 
> In other words, if you're using analog EQ......or an Audison Bit product.
> 
> I do it all the time at work, it helps me save massive amounts of time when tuning/troubleshooting systems of unknown (and sometimes known) origin.
> 
> When I first found that the measured response could be simulated, and that the simulation was EXACLY the same as the real thing, it really made me totally re-think this whole "too complex of an interaction because of all the reflections" thing.


Certainly.. So this software can also account for the room/cabin? That's pretty amazing stuff. What software?


----------



## Babs

Ainuke said:


> After further investigation, it appears that my issue is with the extension cable I'm using on the IMM-6. The laptop I'm using is an Asus 2-in-1 laptop/tablet (never, EVER, buy one of these, BTW) that uses a TRRS jack for audio in/out. Since using the IMM-6 plugged directly into the tablet would bring all kinds of placement & reflection artifacts, I bought a TRRS extension cable so I could just place the mic where needed. I don't know if there's a shielding issue with the cable, or a short of some sort, but even without the mic (just the cable inserted), the signal in REW picks up ~300hz and slopes up in a 45 degree plot to 20k, regardless of output source (even with none plugged in). The same procedure with only the mic inserted yields a proper looking plot for all measured drivers, i.e. no climbing HF slope.
> 
> (Wish I could get my desktop PC out to the car for use, as I have a somewhat high-end sound card in it that would make for less hassle measuring).
> 
> I would love to get a more specialized mic for measurements, but my budget's been long busted for this. An extra $80-$150 to get it "perfect" isn't in the cards, especially if I want better midbass drivers .
> I have StudioSix audio tools on my iPad/Phone that I'll see if I can get to approximate the REW functions with the IMM-6.
> 
> I _do_ appreciate the advice, regardless of my ability to follow it .
> Thanks!


I'm glad you didn't follow my advice.. I've got two IMM-6's sitting on the shelf I thought were junk, so you may have found my solution as well to actually be able to put those to use in a pinch.. Though my even worse old Dell Vostro 3550 doesn't even have sound output from the mini-jack since doing a Win 10 update. Eventually I may replace it.


----------



## Ainuke

Babs said:


> I'm glad you didn't follow my advice.. I've got two IMM-6's sitting on the shelf I thought were junk, so you may have found my solution as well to actually be able to put those to use in a pinch.. Though my even worse old Dell Vostro 3550 doesn't even have sound output from the mini-jack since doing a Win 10 update. Eventually I may replace it.


Turns out the IMM-6 may be crap after all...
tried it again on my iPhone and iPad, and a sloping plot rises with the volume; i.e. if the volume level is 2-3 notches up from 0, there's no discernible disturbance in the background plot. As the volume is increased (via iPhone vol control) the aberrant slope starts to creep in at 20K, like a wedge being inserted from the right side of the graph. As the vol increases, the wedge slides leftwards. Again, this happens if only the mic is inserted, with nothing plugged into the output jack on the IMM-6. Maybe it's some feedback or interference working in internally; I neither know nor care anymore.
I ended up using the iPhone's internal mic (StudioSix says the IMM-6 is no improvement on the internal mic anyway, FWIW), since I can't use REW currently, and adjusted EQ to Hanatsu's curve with pink noise. Sounds *fabulous*! I'll probs just enjoy it just like this for a while before I try a better mic/software combo. (I have to do a few more presets to accommodate the factory HU, for when using that as the source, so my time will be accounted for in that respect).

*Thanks to Hanatsu and all commentators for an awesome thread and discussion!!*


----------



## Niick

Babs said:


> Certainly.. So this software can also account for the room/cabin? That's pretty amazing stuff. What software?


I believe that there are probably multiple softwares out there that are capable of doing this. It's really just math. No magic.

The one I use is called SysTune Pro.

Basically, I understand it like this- so long as you can measure the impulse response.....you're in. 

The IR contains within it all information to characterize the systems frequency response, which contains both phase and magnitude data.


----------



## Babs

Niick said:


> I believe that there are probably multiple softwares out there that are capable of doing this. It's really just math. No magic.
> 
> The one I use is called SysTune Pro.
> 
> Basically, I understand it like this- so long as you can measure the impulse response.....you're in.
> 
> The IR contains within it all information to characterize the systems frequency response, which contains both phase and magnitude data.



That's obviously a whole other realm of measuring I don't have the tools for but that'd make a good thread. Would be a good head to head comparison of predicted vs actual. 


Sent from iPhone using Tapatalk


----------



## Niick

Babs said:


> That's obviously a whole other realm of measuring I don't have the tools for but that'd make a good thread. Would be a good head to head comparison of predicted vs actual.
> 
> 
> Sent from iPhone using Tapatalk


sure, it's become such a part of my workflow that I take it for granted. 

I've been wanting to make a tuning video for a while now, and as it turns out I'm currently (lightly) collaborating on a REW video with another forum member. 

He's really doing all the work. 

Anyways, after the first video series we plan to do another video showing a lot of the more advanced topics concerning acoustic analysis in cars. We plan to use SysTune Pro as a way of showing in real time the things that REW is doing behind the scenes. For example, measuring IR, then adjusting your delay, then measuring IR again and seeing that it now falls into a new time position on the graph. 

With SysTune, IR is measured in real time. So as you adjust delay, the IR moves across the screen, therefore, by simply saving an overlay of the farthest speaker's IR, you simply need to adjust delay until the live trace overlays the stored trace. So long as your mic is in the correct position, the two speakers in question WILL BE time aligned. 

Of course, I just described Left-Right alignment, the process for multiple drive units of the same channel sharing a crossover alignment isn't quite as simple, but it's similar.

Edit: oh yeah, duh! I forgot to mention the acoustic prediction part, we'll cover that too I suppose


----------



## Babs

Niick said:


> sure, it's become such a part of my workflow that I take it for granted.
> 
> I've been wanting to make a tuning video for a while now, and as it turns out I'm currently (lightly) collaborating on a REW video with another forum member.
> 
> He's really doing all the work.
> 
> Anyways, after the first video series we plan to do another video showing a lot of the more advanced topics concerning acoustic analysis in cars. We plan to use SysTune Pro as a way of showing in real time the things that REW is doing behind the scenes. For example, measuring IR, then adjusting your delay, then measuring IR again and seeing that it now falls into a new time position on the graph.
> 
> With SysTune, IR is measured in real time. So as you adjust delay, the IR moves across the screen, therefore, by simply saving an overlay of the farthest speaker's IR, you simply need to adjust delay until the live trace overlays the stored trace. So long as your mic is in the correct position, the two speakers in question WILL BE time aligned.
> 
> Of course, I just described Left-Right alignment, the process for multiple drive units of the same channel sharing a crossover alignment isn't quite as simple, but it's similar.
> 
> Edit: oh yeah, duh! I forgot to mention the acoustic prediction part, we'll cover that too I suppose



Man looking forward to that. I had thought of doing one or two based on what little I do know pertaining to using REW's EQ function, adjusting a curve, creating filter templates, etc. 


Sent from iPhone using Tapatalk


----------



## thebookfreak58

Hanatsu,

Thanks so much for this guide! I assume, that some steps are redundant if using the curves exported from the Jazzi tool?

Any chance for an updated guide using the tool?

Areas I'm a little confused in:

* I understand level match L/R drivers, but where do you match side drivers (tweet-> mid bass) as per the house curve? Or is this done in the autoEQ?
* using the above Jazzi tool, do I no longer use the cross over settings in REW (Set to 'None') and simply match as per the curve? (ie. load driver curve, measure, adjust, re-measure to confirm)?
* once each driver has been level set and EQ and cross over to a house curve driver file. When do I measure a whole side to ensure reflections/superposition is taken into account? And then, do I 'double EQ'? ie. run the AutoEQ with the whole house curve loaded to ensure the entire side side response matches?

Sorry for the many questions! I figure I just need to have a play, but figured I'd ask first


----------



## thebookfreak58

As a further, in Step 4d, it mentions getting all drivers in relative levels to each other in terms of the house curve, but there aren't any steps to do this??

All I understand is choosing a measurement to simply be the reference level that 'sets' the house curve.

Or, is the point that there is no adjustment to channel levels between drivers, and its all done in EQ? (Seems silly to me?)


----------



## Alextaastrup

Babs said:


> Spring for a sure enough mic such as a UMIK-1 or UMM-6 for a USB mic, or something like a Behringer ECM8000 or Dayton EMM-6 for using an external audio interface.


External preamp with 48V is much better solution for this purpose, as you could avoid using the in-built sound card.


----------



## Hanatsu

thebookfreak58 said:


> Hanatsu,
> 
> Thanks so much for this guide! I assume, that some steps are redundant if using the curves exported from the Jazzi tool?
> 
> Any chance for an updated guide using the tool?
> 
> Areas I'm a little confused in:
> 
> * I understand level match L/R drivers, but where do you match side drivers (tweet-> mid bass) as per the house curve? Or is this done in the autoEQ?
> * using the above Jazzi tool, do I no longer use the cross over settings in REW (Set to 'None') and simply match as per the curve? (ie. load driver curve, measure, adjust, re-measure to confirm)?
> * once each driver has been level set and EQ and cross over to a house curve driver file. When do I measure a whole side to ensure reflections/superposition is taken into account? And then, do I 'double EQ'? ie. run the AutoEQ with the whole house curve loaded to ensure the entire side side response matches?
> 
> Sorry for the many questions! I figure I just need to have a play, but figured I'd ask first


I've seen the spreadsheet Jazzi made but it was incompatible with my OpenOffice so I never bothered to try it out. From what I can gather it's basically a "house curve" creator which set up one curve for each speaker and it uses a 1/3oct GEQ to modify the curve if needed.

The spreadsheet should set up the crossover settings by itself if I understand it correctly. 

When you are done correcting for all deviations in the response, with the settings saved into your DSP, rerun the measurement and see if responded as intended. That's a good practice...

I think you should ask Jazzi how the spreadsheet works, I have no way of testing it myself since I don't got Excel.


----------



## Hanatsu

thebookfreak58 said:


> As a further, in Step 4d, it mentions getting all drivers in relative levels to each other in terms of the house curve, but there aren't any steps to do this??
> 
> All I understand is choosing a measurement to simply be the reference level that 'sets' the house curve.
> 
> Or, is the point that there is no adjustment to channel levels between drivers, and its all done in EQ? (Seems silly to me?)


Not really. I meant that you should adjust the levels of each set of speakers to it matches the house curve you loaded somewhat. There are no fixed levels here, all levels are relative to each other, you can begin with midranges and set midbass, subs and tweeters based on that or you can begin with subs and go from there...

You can offset an entire measurement in the "All SPL" tab in top right corner (controls). Just remember to make the same changes in your DSP at the same time, otherwise your measurements will be invalid.


----------



## strohw

I thought I'd put this here because it may help others and I don't ever recall seeing the information in this thread or any other there. If you're getting what you feel is inconsistent measurements with your sweeps then I have some suggestions. 

A while back my wife kicked me off of our relatively new laptop as I was using it almost every night for tuning. I ended up dusting off a 9 year old Dell laptop that I had sitting around. While it ran all the programs just fine I noticed that I was getting inconsistent measurements during my sweeps. An example would be, one sweep giving a +4db convex curve during a tweeter measurement and the next giving an opposite concave result over a specific frequency range.

So, after a little research it seems my laptop wasn't powerful enough nor was the old sigmatel card good enough to work with default settings I had. To fix this I set the input/output buffers to 64k each from 32k. I moved the sweep length from 256k to 128k and I set the number of sweeps to 1 instead of 2. Now, I get excellent repeatably with my measurements during sweeps. 

If you find that your sweeps are giving you different results or giving you results you believe don't make sense then I would suggest trying the above.


----------



## RRizz

After a looong few days, its come to this. A lot to learn, and a big shout out to hanatsu and everyone else for all the great info. Still a little work to do, but its getting there.
Measured response is in red.


----------



## Alextaastrup

strohw said:


> I thought I'd put this here because it may help others and I don't ever recall seeing the information in this thread or any other there. If you're getting what you feel is inconsistent measurements with your sweeps then I have some suggestions.
> 
> A while back my wife kicked me off of our relatively new laptop as I was using it almost every night for tuning. I ended up dusting off a 9 year old Dell laptop that I had sitting around. While it ran all the programs just fine I noticed that I was getting inconsistent measurements during my sweeps. An example would be, one sweep giving a +4db convex curve during a tweeter measurement and the next giving an opposite concave result over a specific frequency range.
> 
> So, after a little research it seems my laptop wasn't powerful enough nor was the old sigmatel card good enough to work with default settings I had. To fix this I set the input/output buffers to 64k each from 32k. I moved the sweep length from 256k to 128k and I set the number of sweeps to 1 instead of 2. Now, I get excellent repeatably with my measurements during sweeps.
> 
> If you find that your sweeps are giving you different results or giving you results you believe don't make sense then I would suggest trying the above.


The problem with old DEL laptops is well known. Their sound cards are simply too bad and are not supposed to be used for precisious measurements. They are intended to feed the in-built louspeakers, which are not good both at low and high ends. One sigmatel card which I have tested had more than 10dB dip in the midrange. I always recommend to use a good external sound card with 48V for a condenser mic (with individual calibration file).


----------



## Hanatsu

Alextaastrup said:


> The problem with old DEL laptops is well known. Their sound cards are simply too bad and are not supposed to be used for precisious measurements. They are intended to feed the in-built louspeakers, which are not good both at low and high ends. One sigmatel card which I have tested had more than 10dB dip in the midrange. I always recommend to use a good external sound card with 48V for a condenser mic (with individual calibration file).


Yeah, it's incredibly important that people use calibration for both soundcard and microphone. Otherwise you might just be chasing ghosts when looking for issues in the FR.


----------



## bnae38

Hanatsu said:


> A
> 
> *Generally speaking, never use narrow band (high Q) EQ in the higher frequencies!
> 
> ^^


What is considered high Q?


----------



## Hanatsu

In the tweeter range, I'd say you don't want to use use Q higher than the actual smoothing of the graph. So Q3-4 max if I were to generalize a bit.


Sent from my iPhone 6 using Tapatalk.


----------



## subterFUSE

Hanatsu said:


> In the tweeter range, I'd say you don't want to use use Q higher than the actual smoothing of the graph. So Q3-4 max if I were to generalize a bit.
> 
> 
> Sent from my iPhone 6 using Tapatalk.



This goes along with the advice of John M, author of REW, when he suggests using the Var Smoothing while using the Auto EQ feature. This prevents higher Q filters at the upper end while allowing them at the low end.


Sent from my iPhone using Tapatalk


----------



## RRizz

Ok, I'm completely new to the pc based tuning, and have a question about doing my T/A.
My head unit is the p99. Typically, I would do my T/A by ear, but the old ears aint what they used to be, for sure.... I tried the calculator at tracerite, and to me, it didn't provide me with acceptable results, so I reverted back to the tape measure, which is always extremely close. I then tweaked by ear to account for other misgivings in installation. Now I'm getting into checking my results with REW, with guidance from hanatsu's thread on the subject.
Firstly, I will say that my Sub IS NOT the furthest driver from my ears. Not sure if that makes a difference. (I have so much to learn about all this stuff)
So last night, I run my sweeps on each individual driver, and tweak to the point where Both my midbass, and my extended range tweeters are coming in at 24ms, Almost spot on.(I chose this number because the furthest driver from me is the right midbass, door mounted) then I check my subwoofer, and it is coming at 22.3ms. Just a touch early.
(To me, it sounds good, and blends well, but I will be competing with this car, and would like it to be as near perfect as the install and equipment allow.) Is this a point of concern?
btw.. all numbers were checked at 5% off 0.


----------



## bnae38

Hanatsu said:


> In the tweeter range, I'd say you don't want to use use Q higher than the actual smoothing of the graph. So Q3-4 max if I were to generalize a bit.
> 
> 
> Sent from my iPhone 6 using Tapatalk.



Ok, just did my first tune to a house curve and it sounds like i have mud in my ears :surprised:

Used this one, not sure who's it was.
http://www.diymobileaudio.com/forum/attachment.php?attachmentid=93473&d=1443633479

Need to re-measure after, then re-evaluate my curve for one thing. Was a lot of trimming in the upper midrange. 

All my levels were great/matched beforehand with the exception of tweets; Left side was strong 3-4db up to 14k, then the right side was strong 3-4db, so i decided to EQ there rather than level match 3-14k.. (maybe i should do that first).


I have many filters with a Q around 5 in the tweets/midrange. What kind of effect would you hear using those? Considering changing them to 3 for starters..


Thanks


----------



## bnae38

Decided to make a house curve more or less resembling my response since i like the tone of it more or less.. and eq to that. Responses are with no eq btw.










Like the results much better for now, much fuller. Also switched narrow Q's to 3 on the tweets.


----------



## cjbrownco

subscribed for later reference


----------



## High Resolution Audio

Subscribed. Thanks for this great post. Appreciate the time and effort you spent to help explaining with pictures, as well. What does one use to mute other speakers? Just pull out rca's? Is that the easiest way?


----------



## bnae38

Can usually use the dsp to mute some channels.


----------



## Hanatsu

subterFUSE said:


> This goes along with the advice of John M, author of REW, when he suggests using the Var Smoothing while using the Auto EQ feature. This prevents higher Q filters at the upper end while allowing them at the low end.
> 
> 
> Sent from my iPhone using Tapatalk


Yeah, Var smoothing is an excellent choice when using the autoEQ function or looking for issues in general. It's a pretty good representation of what we hear.

I do however recommend to ALSO take a look at 1/24-1/48oct smoothing to see if there's any high Q peaks anywhere. It could mean measurement rig issues or other forms of interference.


----------



## Hanatsu

RRizz said:


> Ok, I'm completely new to the pc based tuning, and have a question about doing my T/A.
> My head unit is the p99. Typically, I would do my T/A by ear, but the old ears aint what they used to be, for sure.... I tried the calculator at tracerite, and to me, it didn't provide me with acceptable results, so I reverted back to the tape measure, which is always extremely close. I then tweaked by ear to account for other misgivings in installation. Now I'm getting into checking my results with REW, with guidance from hanatsu's thread on the subject.
> Firstly, I will say that my Sub IS NOT the furthest driver from my ears. Not sure if that makes a difference. (I have so much to learn about all this stuff)
> So last night, I run my sweeps on each individual driver, and tweak to the point where Both my midbass, and my extended range tweeters are coming in at 24ms, Almost spot on.(I chose this number because the furthest driver from me is the right midbass, door mounted) then I check my subwoofer, and it is coming at 22.3ms. Just a touch early.
> (To me, it sounds good, and blends well, but I will be competing with this car, and would like it to be as near perfect as the install and equipment allow.) Is this a point of concern?
> btw.. all numbers were checked at 5% off 0.


*To do T/A by ear you need to make sure that L/R frequency response is matched. T/A each set of drivers individually, i.e left/right tweeters (temporarily lower highpass filter to 1kHz or so), then left/right midranges etc. Keep all other drivers muted in the meantime. Tune to the acoustic center. I recommend using correlated pink noise.

*Subwoofers generally inhibit higher group delay than the rest of the system, matching the delay of the sub with mids can be done several ways. One way is to look at the excess group delay in RoomEQ (you must generate a minimum phase plot). Run ONE channel, i.e all the left or right speakers + sub. Check the group delay of the entire system, should be close to zero in all minimum phase areas (the ones that's flat). Use 1/6oct smoothing when checking the EGD.

_I didn't have any good example on this this computer, this is from a single driver playing but you should get the idea._



Often, matching sub to mids is a simple task to do by simply observing the magnitude response around the crossover point. This could be done by ear to with fairly good accuracy. Play a sine tone (or bandpassed correlated noise) at the acoustic crossover frequency. Invert phase on subwoofer temporarily, then adjust delay until you reach full cancellation (very bad output), then flip phase back. Now you should have good summing around crossover.


----------



## Hanatsu

bnae38 said:


> Ok, just did my first tune to a house curve and it sounds like i have mud in my ears :surprised:
> 
> Used this one, not sure who's it was.
> http://www.diymobileaudio.com/forum/attachment.php?attachmentid=93473&d=1443633479
> 
> Need to re-measure after, then re-evaluate my curve for one thing. Was a lot of trimming in the upper midrange.
> 
> All my levels were great/matched beforehand with the exception of tweets; Left side was strong 3-4db up to 14k, then the right side was strong 3-4db, so i decided to EQ there rather than level match 3-14k.. (maybe i should do that first).
> 
> 
> I have many filters with a Q around 5 in the tweets/midrange. What kind of effect would you hear using those? Considering changing them to 3 for starters..
> 
> 
> Thanks


Weird curve that... try this one instead. I've done a lot of testing and found that this one sounds pretty balanced in multiple types of setups.

*-My reference "House curve"-*

IF you did autoEQ and roomeq applied high Q filters it probably did so in adjacent filter bands to shape the filter curve. Don't put to much thought into that, that's simply creative filter making


----------



## bnae38

Cool will do, easing myself into it instead of all at once.. always sounds a bit muffled when i do it all at once. 

Taking some of the peaks off LR response for starters. Tweets were pretty easy. Subs were pretty easy. Mids are a wreck... suggestions? 










Re-did my levels too, did indeed need some trimming on the left the closer i looked. They're much better matched now.


Edit: this is the eton's in 270mL with some fiber fill. Mostly on axis, a bit off on left. xover at 350 and 3800 24LR.


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## bnae38

They don't look quite so bad with var smoothing . Just making sure nothing out of the ordinary here for midrange, looked pretty ragged at first glance.


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## t0n33

huge thanks, hanatsu, for the wealth of information you've shared in this thread!


----------



## Babs

bnae38 said:


> Cool will do, easing myself into it instead of all at once.. always sounds a bit muffled when i do it all at once.
> 
> Taking some of the peaks off LR response for starters. Tweets were pretty easy. Subs were pretty easy. Mids are a wreck... suggestions?
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Re-did my levels too, did indeed need some trimming on the left the closer i looked. They're much better matched now.
> 
> 
> Edit: this is the eton's in 270mL with some fiber fill. Mostly on axis, a bit off on left. xover at 350 and 3800 24LR.




Ok. Obviously the green plot shows the driver with natural roll off well before the 3800 mark. I suggest working on the individual sides to get those slopes to line up. Will probably entail dropping the xo point on the purple line driver. Do this before any EQ. Then from remeasuring from there the rest can be EQ'd. Looks like most is within around 10db +- so some cuts to each should be able to bring them in line.


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## bnae38

Var smoothing made a difference too . I think that was at 12 or 24.


----------



## Bilalicious

Good lord so much info in this thread, hats off to hanatsu for spending so much time & effort with patience. If only we had a checklist showing steps in ascending order 

I find 80prs navigation to be time consuming. Might be shifting to a dedicated dsp but I always reasoned with myself that a dsp might be an overkill for a simple 3way active setup.


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## sq2k1

subbed....


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## Hoptologist

Hanatsu said:


>


I have a question about that curve and this one that you've posted before,









1. Do both of those curves represent one side+sub or all speakers playing?

2. Because if they represent one side+sub, the whole system response would not be as downward-sloping due to summing between between the left and right speakers from ~80hz-20,000hz, right?

3. Since the decibel range is much greater on the first graph, I would assume that one is for one-side only and the second graph is both sides playing simultaneously?

4. When measuring left-side, it's 5 measurements left ear and 3 measurements right ear. For right-side, it's 6 measurements right ear and 2 measurements left ear. But what about when measuring whole system response with all speakers playing? In that case, would you do 4 measurements right ear and 4 measurements left ear?


----------



## Hanatsu

Hoptologist said:


> I have a question about that curve and this one that you've posted before,
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 1. Do both of those curves represent one side+sub or all speakers playing?
> 
> 2. Because if they represent one side+sub, the whole system response would not be as downward-sloping due to summing between between the left and right speakers from ~80hz-20,000hz, right?
> 
> 3. Since the decibel range is much greater on the first graph, I would assume that one is for one-side only and the second graph is both sides playing simultaneously?
> 
> 4. When measuring left-side, it's 5 measurements left ear and 3 measurements right ear. For right-side, it's 6 measurements right ear and 2 measurements left ear. But what about when measuring whole system response with all speakers playing? In that case, would you do 4 measurements right ear and 4 measurements left ear?


1. All speakers, L+R+Sub.

2. One side+sub would be flatter in the range where both sub and L/R are playing simultaneously, depending on phase shift we could probably see a 6dB boost here in a real world scenario with all drivers on. When you EQ L/R separately to a target response, you need to measure full system afterwards to see how good drivers are summing together (talking about the range where sub, left/right mid are playing together).

3. They are unrelated pretty much, the actual measurement picture something that wasn't tuned manually IIRC.

4. I did made that "rule of thumb" because of repeatability. You might as well use RTA mode and pink noise and move the mic around your head and up/down till you got 300 averages or something. When doing full system measurements, there are bigger chances that combing will show up since T/A won't be correct at all microphone placements. Either you do an equal amount of averaging, 4/4 as you said and apply smoothing (try Var) or you can do RTA and 300 averages, then smoothing isn't required.


----------



## Hanatsu

Here's a full system measurement. Using 300 points of RTA.



Here you can see the difference in accuracy (RTA unsmoothed is very similar to 10 averaged Sine Sweeps):



Important to check summing at crossover...


----------



## Hoptologist

Hanatsu said:


>


Thanks. In that last graph, I noticed a peak in the mids at around 22hz. I've noticed a similar peak in my mids around 20hz and 45hz. Would it do any good to eq those spots to eliminate those peaks so that the mids have a completely smooth roll-off? Or are those peaks so trivial, being at such a low decibel, that it wouldn't do any good? 

Sent from my Nexus 6P using Tapatalk


----------



## Hanatsu

That peak is some microphone distortion, one of the mics I got is kinda messed up.

If is really was there I wouldn't bother with it. Everything below 30Hz is pretty unimportant TBH. I do care how the slope looks at least 1-1,5oct from the crossover point normally though...


----------



## bnae38

I was taking a look at my sub gain tonight again (see sig for gear) and wanted to see if I could turn it up. I checked my eq beforehand and figured I'd reference to the level that i had the least cut on. Looks like 35hz. Found I almost had the gain set too high with 0db 35hz tone (and this wasnt at 75% deck volume, it was at the highest volume I ever really would play at)... sigh. Maybe I should rethink the way I'm Eq'ing. The null at 35hz is 3hz wide and about 5-6db deep. You an see what I've already Eq'd to, should i eq a couple db's higher (blue)? Or maybe even higher? In the end, even with the cut only strategy, you're always boosting your nulls in a way.

Now I know why tons of headroom is nice to have....


----------



## bnae38

This is probably a better strategy, I assume. I gotta go back over the rest of my eq too, and be more realistic... Less boost, even individual.


----------



## Lanson

This thread has been incredibly enlightening!

I noticed that the newest version of REW now includes a really nice time alignment tool and "chirp" in the sweeps. I'm still learning how to use that to dial in my alignment, but the rest of what's in this thread have been very good for me.


I've got a long way to go but I really appreciate this thread, Jazzi's helpful tips and tools, and all the expertise shown in threads like this. REW can be daunting but also extremely powerful.

I've gone through maybe 300 sweeps this point, and all I can say is make sure your earplugs are in good and tight!


----------



## bnae38

So lets say i have a 2db boost at 800hz and a 4db cut at 500 on the LMR. That means my amp is going to put out 4x more power at 800hz compared to 500.

Thinking analytically, bleh... Lol.

Kill some serious headroom if not really thought out. Which is what I've got atm...


----------



## Lanson

bnae38 said:


> So lets say i have a 2db boost at 800hz and a 4db cut at 500 on the LMR. That means my amp is going to put out 4x more power at 800hz compared to 500.
> 
> Thinking analytically, bleh... Lol.
> 
> Kill some serious headroom if not really thought out. Which is what I've got atm...



True, but at 500 and 800hz, your amp is likely not even working hard.


----------



## bnae38

fourthmeal said:


> True, but at 500 and 800hz, your amp is likely not even working hard.


True. 

But think about it this way; if your cutting a good portion of your response down to get a smoother response, you'll lose overall output because your speaker will reach it's mechanical limits at some frequency ranges. That comes with the territory I guess, but kinda crappy when you think everything through, considering 6db=4x power.


Take the sub picture i posted for example.. I can't really crank it back up or I'll distort like crazy at 35hz (and 75hz). Cut only strategy is, more or less, the same as boosting a null in the end. Not that I'm too concerned with the 35hz null, just using it as an example. But from 40-60hz I'm hacking 6-10db off. 

Guess what I'm trying to figure out, in my head, is where the good middle ground lies; between cutting everything to hell and matching response perfectly (and killing off headroom), or placing target level higher and sacrificing some perfection.

I realize the midbass will come in (x'd over at 75) at some point there too; which leads to my next thought.. Shouldn't we be matching each driver to a variation of the house curve that slopes off near x-overs?


Wouldn't be entertaining if it was easy...


----------



## Jscoyne2

bnae38 said:


> True.
> 
> But think about it this way; if your cutting a good portion of your response down to get a smoother response, you'll lose overall output because your speaker will reach it's mechanical limits at some frequency ranges. That comes with the territory I guess, but kinda crappy when you think everything through, considering 6db=4x power.
> 
> 
> Take the sub picture i posted for example.. I can't really crank it back up or I'll distort like crazy at 35hz (and 75hz). Cut only strategy is, more or less, the same as boosting a null in the end. Not that I'm too concerned with the 35hz null, just using it as an example. But from 40-60hz I'm hacking 6-10db off.
> 
> Guess what I'm trying to figure out, in my head, is where the good middle ground lies; between cutting everything to hell and matching response perfectly (and killing off headroom), or placing target level higher and sacrificing some perfection.
> 
> I realize the midbass will come in (x'd over at 75) at some point there too; which leads to my next thought.. Shouldn't we be matching each driver to a variation of the house curve that slopes off near x-overs?
> 
> 
> Wouldn't be entertaining if it was easy...


Your asking everything ive been wondering :0

Sent from my SGH-T999 using Tapatalk


----------



## bnae38

bnae38 said:


> Shouldn't we be matching each driver to a variation of the house curve that slopes off near x-overs?:



target settings>crossovers. derp..

Then again, i suppose you would just match each driver to the house curve, and the existing cross-overs you use will blend them to the same point. Overthinking, Nm..


----------



## subwoofery

bnae38 said:


> True.
> 
> But think about it this way; if your cutting a good portion of your response down to get a smoother response, you'll lose overall output because your speaker will reach it's mechanical limits at some frequency ranges. That comes with the territory I guess, but kinda crappy when you think everything through, considering 6db=4x power.
> 
> 
> Take the sub picture i posted for example.. I can't really crank it back up or I'll distort like crazy at 35hz (and 75hz). Cut only strategy is, more or less, the same as boosting a null in the end. Not that I'm too concerned with the 35hz null, just using it as an example. But from 40-60hz I'm hacking 6-10db off.
> 
> Guess what I'm trying to figure out, in my head, is where the good middle ground lies; between cutting everything to hell and matching response perfectly (and killing off headroom), or placing target level higher and sacrificing some perfection.
> 
> I realize the midbass will come in (x'd over at 75) at some point there too; which leads to my next thought.. Shouldn't we be matching each driver to a variation of the house curve that slopes off near x-overs?
> 
> 
> Wouldn't be entertaining if it was easy...


When you boost the null, does it actually fills in or stays the same? If it's a destructive interference, just skip it. 

When tuning for SQ, there's no middle ground really, you either match the response to your desired target curve (to get the tonality you're after) or you don't. If you don't like loosing that much available volume/level, then you have 2 choices: 
- live with a system that still plays as loud as you want but won't be tonally correct 
- use another driver for the task 

It's really that easy. 

For your information, a nicely tuned SQ system won't sound mellow only, it will rock your socks off if asked to... 

Kelvin


----------



## Lanson

One thing I realized about destructive interference, is there's a possible cure in dropping the response on one speaker, and boosting in another, if it is close to a crossover point. So this can be done by either shifting the (electrical) crossover out of the sensitive zone I had one happening to me in the midrange), and/or by acoustically adjusting this crossover point by boosting one driver up (like the mid), and cutting the tweeter in the same spot. And never be afraid to experiment with phase inversion on a speaker to see if it acoustically lines up. 

REW has that timing feature now, this should help!


----------



## Jscoyne2

Whats up with all these curves? Im seeing 45 at sub frequencies and single digits db at 10k. What about the recommended curves in the beginning of this thread that had no more than a 20db change

Sent from my SGH-T999 using Tapatalk


----------



## Ziggyrama

Awesome thread.

Question regarding level matching:

what method do you guys use for re-measuring the levels after you make adjustments? Do you repeat the full measurement as described in the L/R measurement section of this thread or do you use RTA to get a sense of the levels for each channel and adjust until they look roughly the same?

I did a 1st round of level matching and remeasuring takes forever. I then tried the RTA and that seemed to go faster. I assume RTA should be ok for this, assuming one uses 'adjust RTA levels' option. Thoughts?


----------



## subterFUSE

I do my EQ in real time, with 5 microphones doing a simultaneous special average. So it's always measuring. I just adjust until the response curves are overlapped to the target.


Sent from my iPhone using Tapatalk


----------



## thebookfreak58

subterFUSE said:


> I do my EQ in real time, with 5 microphones doing a simultaneous special average. So it's always measuring. I just adjust until the response curves are overlapped to the target.
> 
> 
> Sent from my iPhone using Tapatalk




Would be awesome if you wrote a little guide to the tools and process you use for tuning??


----------



## Hanatsu

RoomEQ doesn't support multiple microphones as far as I know. For multichannel measurements you need more 'advanced' software.


----------



## Babs

Hanatsu said:


> RoomEQ doesn't support multiple microphones as far as I know. For multichannel measurements you need more 'advanced' software.



And hardware.. I think he's using a mic mixer for the array. 


Sent from my iPhone using Tapatalk


----------



## Babs

Ziggyrama said:


> Awesome thread.
> 
> Question regarding level matching:
> 
> what method do you guys use for re-measuring the levels after you make adjustments? Do you repeat the full measurement as described in the L/R measurement section of this thread or do you use RTA to get a sense of the levels for each channel and adjust until they look roughly the same?
> 
> I did a 1st round of level matching and remeasuring takes forever. I then tried the RTA and that seemed to go faster. I assume RTA should be ok for this, assuming one uses 'adjust RTA levels' option. Thoughts?



The first part of tuning I think is all about making pairs plots overlap. Making the responses overlap at the listening positions and flat without peaks. Narrow dips can be tolerable. It's iterative.. You measure, adjust, measure again. For rough leveling work and side balancing, I say REW RTA is adequate, as it is quick. Others might disagree. 


Sent from my iPhone using Tapatalk


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## bnae38

I have always averaged unsmoothed responses of the 8 sweeps and then applied smoothing. Noticed today that if i apply var smoothing then average them, I get a noticeably different average.


Which way is preferable?


----------



## subterFUSE

Variable.


Sent from my iPhone using Tapatalk


----------



## Ziggyrama

subterFUSE said:


> Variable.
> 
> 
> Sent from my iPhone using Tapatalk


So which one is that? Smooth then average or the opposite?

Seems like smoothing then averaging is the right way to go?


----------



## naiku

Hanatsu said:


> *Make sure you use the same "Target Level" number throughout the entire process.


Does this mean that say I have the target level at 75db for my sub, that for all the other speakers it should be 75db? I cannot get the target and measured lines even remotely close on my tweeters, not sure if I am doing something wrong or just not to worry about it.


----------



## Elgrosso

naiku said:


> Does this mean that say I have the target level at 75db for my sub, that for all the other speakers it should be 75db? I cannot get the target and measured lines even remotely close on my tweeters, not sure if I am doing something wrong or just not to worry about it.


You can select any target you want per driver, and you should to optimize, but just make sure to take notes of all of them to stay in the ballpark for final adjustment of everything later.
Also it's just better to re-measure after eq and adjust levels from there.


----------



## Babs

naiku said:


> Does this mean that say I have the target level at 75db for my sub, that for all the other speakers it should be 75db? I cannot get the target and measured lines even remotely close on my tweeters, not sure if I am doing something wrong or just not to worry about it.



What I do since I use the lowly RTA function is save the plots and check them out over each other on the All SPL screen, then adjust with an idea of a curve in mind. Gets me close. I'll adjust pairs so left = right as much as possible and verify by ear if they stage up.. IID/ILD thing. 

Individual drivers looking about like this currently. I still think I may experiment with a bit of "underlap" pulling crossover points apart a bit since they're crossing really close to full amplitude after EQ work on the tops. 










Sent from my iPad using Tapatalk


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## strohw

naiku said:


> Does this mean that say I have the target level at 75db for my sub, that for all the other speakers it should be 75db? I cannot get the target and measured lines even remotely close on my tweeters, not sure if I am doing something wrong or just not to worry about it.


After you initially set your gain structure you need to measure all drivers individually and decide what driver your going to use to set your target level.

So lets say in a two way front you measure tweeters, mids and sub. Then you overlay your house curve. From here you need to see what driver has the lowest output through it's intended range and then you use that driver to set target level.


----------



## strohw

Babs said:


> Individual drivers looking about like this currently. I still think I may experiment with a bit of "underlap" pulling crossover points apart a bit since they're crossing really close to full amplitude after EQ work on the tops.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Sent from my iPad using Tapatalk


I'll mess around with slopes, underlapping or overlapping crossover points to help them sum probably but you shouldn't need to do that if they are. Use your eq to tailor the slope to get an acoustical lr24 and you'll be good.


----------



## naiku

This is where I am currently at:










In all honesty it sounds pretty good, the piece I am having a hard time with is the dip at about 500Hz from the midbass. Nothing really done with the EQ currently, just flat on everything at the moment while I try to work everything out.

Any suggestions on improvements?


----------



## strohw

You're still showing 10db scale instead of 5db. =]

What mid range are you using?


----------



## naiku

strohw said:


> You're still showing 10db scale instead of 5db. =]
> 
> What mid range are you using?


I am not sure you can change that in REW, at least I have not found the option to do so.

Currently using Dayton RS-75.


----------



## Babs

naiku said:


> I am not sure you can change that in REW, at least I have not found the option to do so.
> 
> Currently using Dayton RS-75.


Wave mouse over top left corner of chart screen and you'll see a + - pop up so you can change to 5db/octave. Also there's a range button for window size top right near the setup button. 





naiku said:


> This is where I am currently at:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> In all honesty it sounds pretty good, the piece I am having a hard time with is the dip at about 500Hz from the midbass. Nothing really done with the EQ currently, just flat on everything at the moment while I try to work everything out.
> 
> Any suggestions on improvements?



That dip may likely be modal and possibly not much to be done about it however I suggest letting crossovers place that burden on your mids instead of midbass. 

I highly suggest, drop the midbass low pass and/or raise midrange high pass so they're not so overlapped. Start with midbass low-pass. Duplicating so much bandwidth between the driver pairs I'd bet is doing wild things to your overall response and phase through that region. Let mids play mids, and midbass play midbass. 

Then level them out again with a rough idea of a curve in mind. Dialing in exactly to a curve can come later. For now you're concerned with individual driver response, general crossovers and leveling... the foundation. That massive dip in midbass at 500 is the reason IMO for a 3-way.. Mids up on dash should be able to cover that unless they're unable to go that low. I'm at 350hz with my GB25's for example so my mid bass drivers are only running up to 350 or so hz. 

Bring up the red midrange to mate up with the other. Also do the same with midrange to tweeter crossover region. Consider even 4khz or even 5khz for tweeter high pass. 

The less that's shared between differently sized and located drivers, the better. Make them cross acoustically where they want to or should. 

Sent from my iPhone using Tapatalk Pro


----------



## raine2jz

subbed


----------



## naiku

Babs said:


> That dip may likely be modal and possibly not much to be done about it however I suggest letting crossovers place that burden on your mids instead of midbass.


I think you are right in that there is not much I can do about it. I did debate having my mids handle it, but at higher volumes the RS75 do not much like playing down low. 



Babs said:


> That massive dip in midbass at 500 is the reason IMO for a 3-way.. Mids up on dash should be able to cover that unless they're unable to go that low. I'm at 350hz with my GB25's for example so my mid bass drivers are only running up to 350 or so hz.


I lowered the mid crossover, but mine are in the kick panels. Not going to be up on the dash as I did not like them being in my face like that, prefer more of a stealthy look. I do have some CDT-ES04 sitting here that I am hoping to squeeze into the kick at some point, I figure that should open up more options since I can play them lower/louder.

Here is where things currently sit after a couple quick changes:










The drop at about 150Hz on the left midbass has never shown up before, so I am going to ignore that for now and assume it will disappear next time I take some more measurements.


----------



## Babs

naiku said:


> I think you are right in that there is not much I can do about it. I did debate having my mids handle it, but at higher volumes the RS75 do not much like playing down low.
> 
> 
> 
> 
> 
> 
> 
> I lowered the mid crossover, but mine are in the kick panels. Not going to be up on the dash as I did not like them being in my face like that, prefer more of a stealthy look. I do have some CDT-ES04 sitting here that I am hoping to squeeze into the kick at some point, I figure that should open up more options since I can play them lower/louder.
> 
> 
> 
> Here is where things currently sit after a couple quick changes:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> The drop at about 150Hz on the left midbass has never shown up before, so I am going to ignore that for now and assume it will disappear next time I take some more measurements.



Indulge me.  Drop midbass down to 400 acoustically. Phase them in with the mids and remeasure, leaving mids where they are. Taking that hump out of the midbass response entirely and try to blend it in. Then once you know mids and mid bass drivers are timed and in phase you may find better coherence in that region. 


Sent from my iPhone using Tapatalk Pro


----------



## naiku

Will likely give that a try Sunday, might get me a kick to try and fit the ES04 here sometime soon. I think they will fit, I just need to relocate a bunch of wiring behind the kick panel and figure out a mount.


----------



## Elgrosso

Everything looks much better! Especially mids/tweeters (maybe the green tweeter could be crossed a little higher)
I'm sure we're many to have the same problem with a dip right at the crossover on midbass/mids. You could try to move it up, or eq more agressively to target if you can?
But the sub needs a lower high pass.
Could you post with 3 or 5db increments?


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## Ziggyrama

Looks pretty good. How does it sound? Did you try playing 1/3oct test tones and see if it is coherent across the entire range?


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## naiku

Made a couple more tweaks today, in all honesty it sounds good. Vocals are up high and sound as though they are past the windshield, stage width is just outside the A-pillars.

I am sure it can be improved upon, but so far it's sounding good.


----------



## j4gates

Glad you are getting this down. I'll be booking a training session soon.


----------



## Babs

naiku said:


> ...so far it's sounding good.



That's what counts. 



Sent from my iPhone using Tapatalk Pro


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## Pariah Zero

I must be doing something wrong...

I'm using a MiniDSP UMIK-1, REW, and AudioTools for iOS for measurement.

I used the mic's calibration files, and sent audio from REW to my system via the AUX input.

I did sweep measurements with REW, and smoothed out the frequency response. The final curves looked very good, and sounded right too (as far as a sweep can sound right)

My problem: as soon as I switched my input source from my computer, there was too much bass... I'm sure some kid in my neighborhood would love it, and it's nice to know I have the headroom, but it's nowhere near the curve I want.

As a backup, I hooked up my iPhone (via aux) and did sweeps with audiotools using the same UMIK-1, and the same calibration file. 

Audiotools appears to agree with what I heard: there was about a 30 dB hump that matched the range pretty well. (i.e. ~20-90 Hz was 30 dB louder than my desired curve) the sweep from audiotools also sounded much more bassy. 10 kHz+ is also hotter than my desired curve.

Pink noise and either AudioTools or the ATF DSP Tool (for my Helix DSP Pro) also agree with what I'm seeing in AudioTools. 

What I measured in REW is completely different from every other method I have.

I'm left thinking my notebook's analog sound card isn't playing nice.

So... what options do I have to get a decent measurement out of REW? It seems that on my system, REW isn't getting good measurements when it is the signal source.

Sent from my iPhone using Tapatalk


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## stixzerjan

Help, could somebody show me where in this thread mentioning how to level match individual speakers to the desired target curves. Thx a zillions

Sent from my ASUS_Z00AD using Tapatalk


----------



## Pariah Zero

stixzerjan said:


> Help, could somebody show me where in this thread mentioning how to level match individual speakers to the desired target curves. Thx a zillions



You can't do that without accurate measurements. My post demonstrates that — I assumed I could get good measurements with REW, and that turned out to be a bad assumption. 

Which is why I asked for help... I'm not getting good measurements with REW. 


Sent from my iPhone using Tapatalk


----------



## naiku

Are you able to play pink noise from another source than your laptop? For example I can either use the generator within REW, or simply play a pink noise file on my tablet bypassing my laptop's output.


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## Pariah Zero

naiku said:


> Are you able to play pink noise from another source than your laptop? For example I can either use the generator within REW, or simply play a pink noise file on my tablet bypassing my laptop's output.



Yes. I have a pink noise CD, FLAC files of the Focal Tools, and AudioTools has its own pink noise generator.

I also remembered I have an old USB sound card that I'd forgotten about, and managed to dig that up. Hopefully it still works.

So, as soon as I get a chance, I'll compare external pink noise sources vs. REW piping pink noise through my notebook's aux output, and finally vs the USB sound card.


Sent from my iPhone using Tapatalk


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## Pariah Zero

Update: after trying the USB sound card, I was able to get good measurements. In the process, I found an EQ buried *deep* inside layers of menus that was responsible for the weirdness with the notebook's main output. 


Sent from my iPhone using Tapatalk


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## Lanson

naiku said:


> I am not sure you can change that in REW, at least I have not found the option to do so.
> 
> Currently using Dayton RS-75.


As a former RS75 user, I can say they are pretty happy up to about 350 Hz, 24dB/oct or so, without an enclosure. They got a little messy under that.


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## naiku

fourthmeal said:


> As a former RS75 user, I can say they are pretty happy up to about 350 Hz, 24dB/oct or so, without an enclosure. They got a little messy under that.


I have it set to 400Hz at the moment, doubt I will go any lower than that. About the only thing it really struggles with is something like Adele, at higher volume they distort quite a bit. 

Going to try getting these 4" speakers in there at some point as that will make life easier I think on both the mids and midbass.


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## Lanson

naiku said:


> I have it set to 400Hz at the moment, doubt I will go any lower than that. About the only thing it really struggles with is something like Adele, at higher volume they distort quite a bit.
> 
> Going to try getting these 4" speakers in there at some point as that will make life easier I think on both the mids and midbass.


Not to hijack the thread away from its purpose here but Fountek FR89's, or GR Research LGK 1.0's come to mind to solve the problem. I used the FR88 and 89, both awesome units. The RS75 fits in smaller places due to sheer diameter but the FR89EX is really quite close in total size, but with excellent lower playing ability (usable excursion is excellent.) I put one in tiny a "pod" in a Vette door, crossed very low (for experimentation), was able to play cleanly down to ~200hz or so, very easily. Settled on 500hz for other reasons but the speaker didn't mind and the REW measurements showed very little distortion all the way down to 150hz or so.

Wavecor is also also a great choice, but their rectangular shape may not help with the size issue. The FR89EX has a tiny baffle area and squeezes in places.


OK back to the program.


----------



## naiku

fourthmeal said:


> OK back to the program.


Yep (but thanks for the info on potential new mids if I can't get the ES04 in there).

So... this happened:










Just need to see if I can do anything about the dip at 150Hz on the left midbass. Oh yeah, it sounds amazing


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## Babs

naiku said:


> Yep (but thanks for the info on potential new mids if I can't get the ES04 in there).
> 
> So... this happened:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Just need to see if I can do anything about the dip at 150Hz on the left midbass. Oh yeah, it sounds amazing



Looking great Ian. I'd bring the areas under and over that dip down to meet it. Starting with 100-400. Then 800-5k or so. 


Sent from my iPhone using Tapatalk Pro


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## dannyb

Hi, I've got as far as measuring and importing and auto eqing, destroyed a tweeter in the process..

The question I have is, when are you setting gains on the amp? There's a lot of talk of levels but when do I set my amp gains? I'll be doing it by ear.


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## Pariah Zero

dannyb said:


> Hi, I've got as far as measuring and importing and auto eqing, destroyed a tweeter in the process..
> 
> 
> 
> The question I have is, when are you setting gains on the amp? There's a lot of talk of levels but when do I set my amp gains? I'll be doing it by ear.



The maximum level of the gains needs to be set first - it's your baseline 'thou shalt go no louder' point. You can turn the gains down from there to suit your tuning needs, but never above it.

The key enemy here is heat. The watt rating for a speaker is the maximum RMS wattage the speakers can handle without overheating.

When gains are set too high, the signal is clipped. It sounds bad, but far worse is that instead of getting short bursts of power, and cooling most of the time, the speaker gets long powerful bursts of current, with no time to cool.

It's kind of like the engine in your car: the cylinder has bursts of very high temperatures, but most of the time the cylinder is cooling off.

If you took the same metal and gave it constant exposure to the full heat of burning gasoline, it will melt.


Sent from my iPhone using Tapatalk


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## JVD240

Did you have your crossovers set properly?

Shouldn't burn up a tweeter just from measuring/eq-ing.


----------



## banshee28

So...I have been following this and a few other REW threads for a week or so now and starting to tune my system with a MiniDSP C-DSP. So far I am starting with the TA, using Jazzi's charts and simple measuring (for now), then level matching, and half-way through measuring response and averaging, then matching the house curve. The problem is, I cant seem to get the EQ, that I save both as .txt, (export filter settings as txt) and "save this filter set" using the top EQ Filters section to load on the DSP. I save them, but when I go into the C-DSP and try import, it looks for the file and "loads" but never shows up in the chart or eq points under Advanced. Any idea what I am doing wrong or how can I get them in there.

I did manually enter the numbers for each PEQ point, but thats very time consuming and I would like to find out how to do this properly. Also is there a way to do more than 6 PEQ? It seems like I get better results of I use Generic for Equalizer vs MiniDSP.


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## Elgrosso

Strange.
Maybe... Which setting in rew did you use for the eq? One of the top right boxes, you can select mini, mini96k, mini 2x8 etc. be sure to use the simple mini for the C.

Then maybe you should measure each driver first, then eq each driver, then level, then ta, then global eq (input).


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## banshee28

Elgrosso said:


> Strange.
> Maybe... Which setting in rew did you use for the eq? One of the top right boxes, you can select mini, mini96k, mini 2x8 etc. be sure to use the simple mini for the C.
> 
> Then maybe you should measure each driver first, then eq each driver, then level, then ta, then global eq (input).


So, I think I tried a few diff ones, but I will make sure to keep the EQ on "MiniDSP" only. However what is the format of the EQ txt file supposed to be? I will post an example here in a min. For measuring, now that I think about it, I did not put any TA in there yet, so that should not be an issue but I think my main issue here is with the Target Level. Mine seems to be about 62db. I guess each speaker measurement I take I need to make sure to level up and match this level right?
Here is an example txt file:


Code:


Filter Settings file

Room EQ V5.17
Dated: Dec 22, 2016 10:55:25 PM

Notes:

Equaliser: MiniDSP
Dec 22 19:11:56
Filter  1: ON  PK       Fc     198 Hz  Gain  -7.1 dB  Q  5.27
Filter  2: ON  PK       Fc     284 Hz  Gain  -6.7 dB  Q  5.00
Filter  3: ON  PK       Fc     287 Hz  Gain  11.0 dB  Q  5.00
Filter  4: ON  PK       Fc     511 Hz  Gain  -4.0 dB  Q  5.00
Filter  5: ON  PK       Fc     761 Hz  Gain  -2.7 dB  Q  1.00
Filter  6: ON  PK       Fc     780 Hz  Gain   5.1 dB  Q  5.00


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## Lanson

I just copy-paste the biquads


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## Elgrosso

banshee28 said:


> So, I think I tried a few diff ones, but I will make sure to keep the EQ on "MiniDSP" only. However what is the format of the EQ txt file supposed to be? I will post an example here in a min. For measuring, now that I think about it, I did not put any TA in there yet, so that should not be an issue but I think my main issue here is with the Target Level. Mine seems to be about 62db. I guess each speaker measurement I take I need to make sure to level up and match this level right?
> Here is an example txt file:
> 
> 
> Code:
> 
> 
> Filter Settings file
> 
> Room EQ V5.17
> Dated: Dec 22, 2016 10:55:25 PM
> 
> Notes:
> 
> Equaliser: MiniDSP
> Dec 22 19:11:56
> Filter  1: ON  PK       Fc     198 Hz  Gain  -7.1 dB  Q  5.27
> Filter  2: ON  PK       Fc     284 Hz  Gain  -6.7 dB  Q  5.00
> Filter  3: ON  PK       Fc     287 Hz  Gain  11.0 dB  Q  5.00
> Filter  4: ON  PK       Fc     511 Hz  Gain  -4.0 dB  Q  5.00
> Filter  5: ON  PK       Fc     761 Hz  Gain  -2.7 dB  Q  1.00
> Filter  6: ON  PK       Fc     780 Hz  Gain   5.1 dB  Q  5.00



Don’t know what kind of file is that, looks more like a generic EQ export.
The biquad txt file should look something like this:








It’s the «*save filter coef to file*» down in the filter tasks tab

For the target level you can choose whatever you want per driver, they don't have to match. You’ll adjust global levels later.
So here the idea is more to select a target that is close to your measurement. More or less depending of your system, if you want to cut or boost etc.
You’ll have to play with all settings in filter task to see which result is «*flatter*», then re-measure to see by yourself.


----------



## banshee28

Thanks guys...I will look at the "save filter coef to file" since I dont think I choose that one yet, so maybe thats whats missing! Will try that and see how it works.


----------



## sq2k1

I just now started tinkering with this guide and I figured I would condense Hanatsu's posts into one guide which can be downloaded and printed if need be...I included it as a .pdf format for ease of use. Hope someone can make use of it. I tried to include a .docx file for enabling hyperlinks as well, but I could not include it as an attachment. 

Thank you Hanatsu for the awesome work and time you put into this guide. I look forward to getting further into it as time passes.


----------



## crackinhedz

thanks sq2k1, much easier to keep up with! a few things I missed that you layed out nicely.


----------



## sq2k1

what you just stated crackinhedz is why I condensed it down to a single pdf.... scouring through forum posts can be a pain if you need to look something up while doing the actual measurements. But I am glad you find it useful.


----------



## freemars

sq2k1 said:


> I just now started tinkering with this guide and I figured I would condense Hanatsu's posts into one guide which can be downloaded and printed if need be...I included it as a .pdf format for ease of use. Hope someone can make use of it. I tried to include a .docx file for enabling hyperlinks as well, but I could not include it as an attachment.
> 
> Thank you Hanatsu for the awesome work and time you put into this guide. I look forward to getting further into it as time passes.


Thanks for putting that together. Perhaps you could upload the text version to a Google doc. That way, you could leave the hyperlinks in. 

Again, thanks.


----------



## dannyb

Are these cross over numbers correct? My tweeters are meant to be crossed at 2k, but ive had to put in some funny numbers into rew to get the curve to align.

|I followed the guide including setting the xovers in rew but now i have only 4 filters to use as ive used 2 of the 6 for xovers. I have a c-dsp. Would it be better to use the extra 2 filters and just let the dsp set the xovers? Im amazed ive got this far tbh.

A special thanks goes out to all who have helped to get me and others to where we are. The journey is just beginning.


----------



## dannyb

text too small

Well my 2 xover slopes are 750hz each for the 24 db slope to match the house curve. I didnt like most of the auto eq that rew gave me so i just adjusted the q's down to less than 1 for the other 4 filters.


----------



## JVD240

You have your tweeters crossed at 750Hz? Am I understanding you correctly?


----------



## dannyb

Elgrosso said:


> For the target level you can choose whatever you want per driver, they don't have to match. You’ll adjust global levels later.
> So here the idea is more to select a target that is close to your measurement.


So i can use a different target level per driver? I was under the impression I had to take the the quietist driver set the taget level and then apply that to each and every other driver before doing the eq?

It would be waaay easier to do it as youve said.


----------



## dannyb

No, using Jazzis spreadsheet, i put all the details of my drivers in and it generated the house curve you see in the pic. I set them in speadsheet at 2k for the tweeters. To get the xover in REW to match the house curve though ive had to input a HP at 750 hz @ 12 db twice to generate a 24db slope that matches the house curve. God that sounds confusing.


Running HSK165xl with a HX250 in a tuned box, Alpine PDXV9 and mini c-dsp.


----------



## dannyb

I think its something to do with electrical and acoustic xovers, im trying to understand.

For the people with a mini c-dsp, how have you over come the fact that after you've set your crossovers, you've used 4 bands of peq already which only leaves 2 for the rest of the driver. Feel a bit short changed :/


----------



## sq2k1

So I followed the guide and tuned my system and the result is so much better than prior.... I can only imagine how well going parametric would be as compared to GEQ....but nonetheless, I am pleased with the results(for now )


----------



## My98RT10

Hi everybody,
I hope I am at the right place to get some advise ;-)

I am new to the measuring and tuning thing, I have just purchased a UMIK-1 and started to study REW. Reason is, that I upgraded my DSP (Sony XDP-210) to the bigger XDP-4000x, which offers much more tuning possibilities (ok, compared to today's DSPs it is probably somewhat limited ;-)).

So I did my first measurings last weekend and tried to eq the FR. I also read a lot about how to use REW here in the forum and thanks to all who donated their valuable time, knowledge and experience!!

However, there is one thing, that still puzzles me...and this is regarding the target settings under the auto EQ tab. I am not sure, what is the optimal setting here for my case.

What is my case? I would like to eq the response for my left and right channel (separately). My system consists of a simple 2-way component set plus a subwoofer. The sub is crossed actively by the XDP-4000x at 99Hz and 72db/octave (same freq and slope for the 6.5" woofer here) whereas the tweeters are crossed by the passive x-over coming with the set (Alpine SPX-177r).

I would like to EQ the complete channel (e.g. L + sub). What would be the right target settings with regards to speaker types, frequencies and slopes in this autoEQ section? Is the x-over freq of my sub (99Hz) relevant here and if so, how does that need to be considered? Or is it completely irrelevant and all these settings here are purely used to shape the overall target curve? And what would the ideal target curve for my case look like?

Any feedback/input is very much appreciated! Thanks!


----------



## Babs

My98RT10 said:


> Hi everybody,
> I hope I am at the right place to get some advise ;-)
> 
> I am new to the measuring and tuning thing, I have just purchased a UMIK-1 and started to study REW. Reason is, that I upgraded my DSP (Sony XDP-210) to the bigger XDP-4000x, which offers much more tuning possibilities (ok, compared to today's DSPs it is probably somewhat limited ;-)).
> 
> So I did my first measurings last weekend and tried to eq the FR. I also read a lot about how to use REW here in the forum and thanks to all who donated their valuable time, knowledge and experience!!
> 
> However, there is one thing, that still puzzles me...and this is regarding the target settings under the auto EQ tab. I am not sure, what is the optimal setting here for my case.
> 
> What is my case? I would like to eq the response for my left and right channel (separately). My system consists of a simple 2-way component set plus a subwoofer. The sub is crossed actively by the XDP-4000x at 99Hz and 72db/octave (same freq and slope for the 6.5" woofer here) whereas the tweeters are crossed by the passive x-over coming with the set (Alpine SPX-177r).
> 
> I would like to EQ the complete channel (e.g. L + sub). What would be the right target settings with regards to speaker types, frequencies and slopes in this autoEQ section? Is the x-over freq of my sub (99Hz) relevant here and if so, how does that need to be considered? Or is it completely irrelevant and all these settings here are purely used to shape the overall target curve? And what would the ideal target curve for my case look like?
> 
> Any feedback/input is very much appreciated! Thanks!


What you are asking for is on the topic of "target" or "house" curve.. That's where your personal taste for tonality will come into play a bit. There are some somewhat established norms, but in the end, it's what sounds balanced, smooth and coherent to you. I've been told all kinds of stuff like "flat from 200hz up" and 20db total delta between 20hz and 20khz. I think after enough tuning, you'll establish a tonality that's balanced for your car. I don't believe there's any single curve that's right for all cars or systems. Crossover settings are relevant in that crossover regions you want to keep an eye out for any destructive FR stuff that may happen due to phase or timing being out etc. Other than that, the overall tonality should be smooth without spikes or peaks (narrow unavoidable dips can be forgiven). And possibly even more important, left=right.


----------



## My98RT10

Babs said:


> What you are asking for is on the topic of "target" or "house" curve.. That's where your personal taste for tonality will come into play a bit. There are some somewhat established norms, but in the end, it's what sounds balanced, smooth and coherent to you. I've been told all kinds of stuff like "flat from 200hz up" and 20db total delta between 20hz and 20khz. I think after enough tuning, you'll establish a tonality that's balanced for your car. I don't believe there's any single curve that's right for all cars or systems. Crossover settings are relevant in that crossover regions you want to keep an eye out for any destructive FR stuff that may happen due to phase or timing being out etc. Other than that, the overall tonality should be smooth without spikes or peaks (narrow unavoidable dips can be forgiven). And possibly even more important, left=right.


Thanks for the feedback. I was looking at some measurements I made recently and came across one strange thing where maybe some one can give me a helping Hand on.... 

I had measured my drivers individually without any crossover set. As it turns out, my sub shows a huge dip in FR at 90 Hz. Has anyone an explanation for this? It is a sealed footwell sub, 8" driver in a small enclosure (approx. 10 Liters). Before any measurements I had set the crossover to 99Hz because it sounded best to my ears. Now, seeing this dip, I have my doubts if 99Hz is really recommended. I should probably cross it at 78Hz to avoid that dip!? What do you guys think?


----------



## My98RT10

I will do a nearfield measurement next. Maybe this dip is caused by room/cabin effects? We'll see....


----------



## trenion

Thank you for this complete guide. It will be very useful for me since I'm relatively new with making mobile audio. Got to share this information with my friends too.


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## My98RT10

My98RT10 said:


> I will do a nearfield measurement next. Maybe this dip is caused by room/cabin effects? We'll see....


So I did a nearfield measurement of my footwell sub the other day and this is the result:










Is it fair to assume that the dip at 90Hz in the previous measurement from the listening position (drivers seat) is caused by the cabin acoustics!? However, I am wondering about the dip at 160Hz now...?


----------



## Elgrosso

My98RT10 said:


> So I did a nearfield measurement of my footwell sub the other day and this is the result:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Is it fair to assume that the dip at 90Hz in the previous measurement from the listening position (drivers seat) is caused by the cabin acoustics!? However, I am wondering about the dip at 160Hz now...?


How did you measure this one? Near-field should be plenty full here that’s strange (like 1" from the cone).

I (as many) have the same effect with my sub, but placed behind me almost in the middle of the car.
My dip is around 170hz so not really an issue, in fact it helps. But the near-field measurements are full up to 2k.
This dip moves if I move the sub of course, wavelengths interaction between both windshields that causes cancellation I guess (could calculate the distance etc)

You could try different points of measurements, like 8 around your driver seat to see how it's affected, see if it's really an issue.
Or you could also leverage this dip, and cross right on it with a shallower slope, one that would give you the wanted acoustic slope (so could be anything between 80 to 120hz or even anything else)


----------



## My98RT10

I put the microphone right in front of the cone, actually less than 1"! The sub was still in the car (footwell) but I assumed that cabin effects should have been eliminated by this type of measurement. Maybe I need to do another measurement with the sub outside the car in a reflection free environment!?


----------



## Elgrosso

Oh I forgot, my car is a convertible and I did this the top down, seats down and everything open. very close to a clean near-field I guess. When in your case even everything open it’s still trapped in a tunnel.
But anyway you won't learn a lot outside, I think multi points at driver side will give you more.


----------



## ARCuhTEK

Old thread but I need this information, so thank you to the OP.


----------



## cesarius

Thanks for the this RTA Guide.


----------



## Rivers

Can someone tell me which channels I should be plugging into my Audison Bit one DSP if I don't have an Aux input on my head unit?


----------



## Hoptologist

Rivers said:


> Can someone tell me which channels I should be plugging into my Audison Bit one DSP if I don't have an Aux input on my head unit?


AFAIK, Aux 1 or Aux 2. But you'll need a 3.5mm male to 2RCA male stereo cable. Something like this https://www.amazon.com/Cable-iXCC-S...TF8&qid=1497944821&sr=1-3&keywords=aux+to+rca


----------



## Rivers

Does any one know if I can export the Auto EQ recommended filter settings to the Helix DSP 2? I do not see as part of the Equaliser options.

Thanks!


----------



## bnae38

Rivers said:


> Does any one know if I can export the Auto EQ recommended filter settings to the Helix DSP 2? I do not see as part of the Equaliser options.
> 
> Thanks!


Export? Not that I know of. But use the usm810 filters or 360.3 (q is limited though). The filter definitions for those two are closer to the helix's than the generic filter set.


----------



## Rivers

Does any one have any advice on me on how to EQ this out? Using Focal Utopia BE 6.5" speakers and a Helix DSP2. Both L+R speakers have a huge dip near 500 hz and the difference between peaks and dips are around 20db.


----------



## Ziggyrama

Rivers said:


> Does any one have any advice on me on how to EQ this out? Using Focal Utopia BE 6.5" speakers and a Helix DSP2. Both L+R speakers have a huge dip near 500 hz and the difference between peaks and dips are around 20db.


I have the same problem in my Subaru. Both sides have a suck out around 550Hz. I cut around it a bit, boost the dip area a little and that gave a a curve that is close to what I want. The dip did respond to boosting but too much introduces too much distortion and does not sound better. So, for me, the answer was a little bit of both cutting and boosting, net level in the suck out area being close to about +2db.

Sent from my VS986 using Tapatalk


----------



## Rivers

Ziggyrama said:


> I have the same problem in my Subaru. Both sides have a suck out around 550Hz. I cut around it a bit, boost the dip area a little and that gave a a curve that is close to what I want. The dip did respond to boosting but too much introduces too much distortion and does not sound better. So, for me, the answer was a little bit of both cutting and boosting, net level in the suck out area being close to about +2db.
> 
> Sent from my VS986 using Tapatalk


How many db did you boost up in the dips? I have them up at +6db now which isn't ideal from what I understand.


----------



## Elgrosso

Ziggyrama said:


> I have the same problem in my Subaru. Both sides have a suck out around 550Hz. I cut around it a bit, boost the dip area a little and that gave a a curve that is close to what I want. The dip did respond to boosting but too much introduces too much distortion and does not sound better. So, for me, the answer was a little bit of both cutting and boosting, net level in the suck out area being close to about +2db.
> 
> Sent from my VS986 using Tapatalk


Are these one point only or average?


----------



## Ziggyrama

Rivers said:


> How many db did you boost up in the dips? I have them up at +6db now which isn't ideal from what I understand.


I am boosting by about 4db on the left and 3db on the right, in the trouble regions. They are similar on both side but not identical. Overall, the driver side left driver was harder to EQ than passenger side. Any more boost and I think some audible distortion starts to come through. Also, REW reports significantly higher distortion levels in those regions. This is what my EQ curves look like for my left and right mids. As you can see, I am mostly cutting in order to keep the trouble spot boost reasonable:

LEFT:










RIGHT:










This is what they measure, roughly, since I corrected the right channel dip around 1500Hz. Need to do some minor tweaks on my tweeters too:


----------



## Ziggyrama

Elgrosso said:


> Are these one point only or average?


I always average my measurements using Hanatsu's method:

Left: 5 left, 3 right
Right: 6 right, 2 left

In the post above, the curves are the averages of those measurements. That being said, in lower frequencies, the averaging isn't that useful since the wavelength is very large and so there is really very little variation between readings. Pretty much below 1KHz the readings are very consistent if you move the mic around your ear. They do different significantly when you move the mic to the other side of your head.


----------



## bnae38

Ziggyrama said:


> I always average my measurements using Hanatsu's method:
> 
> Left: 5 left, 3 right
> Right: 6 right, 2 left
> 
> In the post above, the curves are the averages of those measurements. That being said, in lower frequencies, the averaging isn't that useful since the wavelength is very large and so there is really very little variation between readings. Pretty much below 1KHz the readings are very consistent if you move the mic around your ear. They do different significantly when you move the mic to the other side of your head.


Must be running two-way? Not suggesting running 3 way is the answer to the world's problems... but might be worth experimenting with bringing a mid to another position to cover those frequencies?


----------



## Ziggyrama

bnae38 said:


> Must be running two-way? Not suggesting running 3 way is the answer to the world's problems... but might be worth experimenting with bringing a mid to another position to cover those frequencies?


Good eye. Yes, this is a 2-way setup. I would probably benefit from moving a mid up higher but the install gets more complicated. May e one of these days I will grow a set and go with a 3-way 

Sent from my VS986 using Tapatalk


----------



## bnae38

Ziggyrama said:


> Good eye. Yes, this is a 2-way setup. I would probably benefit from moving a mid up higher but the install gets more complicated. May e one of these days I will grow a set and go with a 3-way
> 
> Sent from my VS986 using Tapatalk


Gotcha, could be worth staging some mids up and seeing what kind of response you get. Agreed, going to be more work to actually go there plus considerably more tuning work.


----------



## Elgrosso

Ziggyrama said:


> I always average my measurements using Hanatsu's method:
> 
> Left: 5 left, 3 right
> Right: 6 right, 2 left
> 
> In the post above, the curves are the averages of those measurements. That being said, in lower frequencies, the averaging isn't that useful since the wavelength is very large and so there is really very little variation between readings. Pretty much below 1KHz the readings are very consistent if you move the mic around your ear. They do different significantly when you move the mic to the other side of your head.


Oops I think I quoted the wrong post, it was for:






Rivers said:


> Does any one have any advice on me on how to EQ this out? Using Focal Utopia BE 6.5" speakers and a Helix DSP2. Both L+R speakers have a huge dip near 500 hz and the difference between peaks and dips are around 20db.


----------



## sareea

Hello
Thank you a lot for the great guide. 
I only started understanding after spending few hours of wrong measurements lol. 

Can you please reupload your dropbox data ? Cd... curve... pink noise bursts...


----------



## bnae38

sareea said:


> Hello
> Thank you a lot for the great guide.
> I only started understanding after spending few hours of wrong measurements lol.
> 
> Can you please reupload your dropbox data ? Cd... curve... pink noise bursts...


Pdf version post313.


----------



## Rivers

Can someone tell me if the 5/3 ratio for the left and 6/2 for the right should be inverted of still the same in a Right hand drive car?



Hanatsu said:


> *Microphone measurement technique*
> 
> _If you look in a manual of an auto-tune DSP or ask 10 different 'experts' I'm sure you get different answers every time. I will present my technique here, in my experience, it has worked best in those systems I've installed. I've sort of 'back engineered' this technique via comprehensive listening tests... _
> 
> *So how do you place your microphone while measuring?*
> 
> Good question! Sit in the car, hold the microphone as the pictures below describe. Run one sweep in RoomEQ for EACH POINT. 8 sweeps in total for each individual speaker. Hold the microphone still while running the sweep and make sure the microphone doesn't hit your head or anything.
> 
> *FOR SUBWOOFER MEASUREMENTS, A SINGLE MICROPHONE PLACEMENT IS ENOUGH. PLACE IT IN THE MIDDLE OF THE HEADREST OR IN FRONT OF YOUR HEAD (you don't even need to be in the car for this one)*
> 
> - As I said before, measure in a quiet area.
> - Measure at moderate/"normal listening" volume ~90dB or so.
> - Use hearing protection if you want, the sweep is annoying to listen to.
> 
> 
> 
> 
> 
> 
> 
> *!! AVERAGE THE MEASUREMENTS FROM THESE POINTS AS DESCRIBED IN MY LAST POST !!*
> 
> *Why 5/3 ratio for the left side and 6/2 ratio for the right side?*
> 
> I believe this is due more "hearing crosstalk" left side, the speaker is more in front of us and also closer to both ears. The listening tests confirm that this is the "best" way to average (IME).
> 
> Pro-tip: Use a battery charger while measuring / tuning. Your battery will thank you


----------



## sareea

bnae38 said:


> Pdf version post313.


CD and housecurve ... 
Got them?


----------



## rockinridgeline

Rivers said:


> Can someone tell me if the 5/3 ratio for the left and 6/2 for the right should be inverted of still the same in a Right hand drive car?


Yes for a right hand drive swap the ratios; that was covered pretty early on in the thread.


----------



## conehunter76

Hanatsu said:


>


Question regarding the Line-in from preamp to laptop. I have a Behringer ECM 8000 running into an M-Audio MobilePre USB preamp, which is running into my laptop with a usb cable. Should I use the line-out from the preamp into the line-in on the laptop, if I'm already using the usb cable from the preamp to the laptop?

I've taken readings with and without the line-in connection and the measurements are way off from each other.


----------



## sareea

I want to share something. 
I have been trying to tackle piercing high mids. 
Until i put the time to measure with sweeps insead of pink noise. And the sweeps was much more accurate in the >2.5khz and region , and from the first Equalization the problem disappeared. 
I remeasured with pn again to check what the h was this problem, and then i saw the difference. I wonder why, it even happens with the generator of roomeq, the fr is the same up until the 2.5-3khz region and up, the rta was less db than the sweep, and i guess the rta was showing lower values that it is actually.. from this time and on i will only use sweeps until I understand this...
Any one experienced this ?


----------



## Elgrosso

It sounds like you had the wrong settings when using rta, like fft length etc.
It could look like the difference between pink and white noise in way.
Can't find quickly a good page that summarizes that but try to look at the rew pages they're really good.
But yes sweeeps are the way to go


----------



## sareea

Elgrosso said:


> It sounds like you had the wrong settings when using rta, like fft length etc.
> It could look like the difference between pink and white noise in way.
> Can't find quickly a good page that summarizes that but try to look at the rew pages they're really good.
> But yes sweeeps are the way to go



Hhh I was so frustrated that I faced this issue for more than a month ! It would have been better time-wise to use sweeps from the very begenning

look at the picture,
I used 65536 fft for mono pn. and this shows also with the stereo option from rew generator.








image of 9 averaged sweeps (pink) and rta of pn


----------



## JH1973

Thank you for posting this tutorial! What a great reference for greenhorns like me.....


----------



## Mahapederdon

sareea said:


> I want to share something.
> I have been trying to tackle piercing high mids.
> Until i put the time to measure with sweeps insead of pink noise. And the sweeps was much more accurate in the >2.5khz and region , and from the first Equalization the problem disappeared.
> I remeasured with pn again to check what the h was this problem, and then i saw the difference. I wonder why, it even happens with the generator of roomeq, the fr is the same up until the 2.5-3khz region and up, the rta was less db than the sweep, and i guess the rta was showing lower values that it is actually.. from this time and on i will only use sweeps until I understand this...
> Any one experienced this ?


Did you ever figure this out. I'm having the same problem but tuning with sweeps is dificult for me because my dsp usb cable is short so ide have to set the laptop in the car. With rta I can just run pink on a flash drive. I'd be stoked if someone could help here. I've been using rew in the car for a few months but every tune is way bright sounding.


----------



## stixzerjan

Quick question. How do you normally do L & R eq. Do u run individually, go to auto eq? Or u must make and average of L&R. Go to EQ and input the same values for both channel? Definitely we do this after we EQ each driver right? 

Sent from my ASUS_Z00AD using Tapatalk


----------



## Mahapederdon

stixzerjan said:


> Quick question. How do you normally do L & R eq. Do u run individually, go to auto eq? Or u must make and average of L&R. Go to EQ and input the same values for both channel? Definitely we do this after we EQ each driver right?
> 
> Sent from my using Tapatalk


I think it's best to subtract one side from the other. It depends on your dsp and how many filters you have. Rew has the add subtract feature, I myself haven't gotten that far.


----------



## Babs

I’ve taken a different approach lately. Rather than extensively and exhaustively interpreting and making major parametric decisions, I’ve backed off to old school.. Plain old 1/3 octave RTA. In audiotools I can pick any curve target txt file to tune to, then simply go at it, leveling and EQing individual drivers, then TA and phase so left side and right side match. I’ve done it a couple tries now and I tell ya, best image focus, stage size, separation and tonality I’ve ever been able to achieve in a very short amount of tuning time. As far as EQ goes, I for one am done with overthinking it. It’s real time with an RTA running on my iPad, while laptop is dedicated for the DSP. Works quick and gets it done. 


Sent from my iPad using Tapatalk Pro


----------



## Babs

Pay no attention to the response, that’s a loud room ambient noise.. just to show the two basic apps in Audiotools which can apply a curve target easily for reference.. 1/2 whitledge curve here in “RTA”, and in “FFT”. Both with Audiotools by Studio Six Digital. 

















Sent from my iPad using Tapatalk Pro


----------



## AyOne

Babs said:


> I’ve taken a different approach lately. Rather than extensively and exhaustively interpreting and making major parametric decisions, I’ve backed off to old school.. Plain old 1/3 octave RTA. In audiotools I can pick any curve target txt file to tune to, then simply go at it, leveling and EQing individual drivers, then TA and phase so left side and right side match. I’ve done it a couple tries now and I tell ya, best image focus, stage size, separation and tonality I’ve ever been able to achieve in a very short amount of tuning time. As far as EQ goes, I for one am done with overthinking it. It’s real time with an RTA running on my iPad, while laptop is dedicated for the DSP. Works quick and gets it done.
> 
> 
> Sent from my iPad using Tapatalk Pro


It's a great app! I got my highest score from holding my phone next to my ear and adjusting real time. Right know I'm using REW auto eq with presets like a GEQ so I can continually adjust without running out of bands, then I have enough leftover for PEQ bands for specific areas. Works really well and faster. I think I just dove into this way to fast, trying run before I can even stand. LOL.


----------



## Mahapederdon

Heres a good read. There is 5 so far on the site and they are kinda hard to navigate but it has some really good info. Here ya'll go.
http://www.audiofrog.com/community/tech-tips/time-alignment-part-5-putting-it-all-together/


----------



## Babs

AyOne said:


> It's a great app! I got my highest score from holding my phone next to my ear and adjusting real time. Right know I'm using REW auto eq with presets like a GEQ so I can continually adjust without running out of bands, then I have enough leftover for PEQ bands for specific areas. Works really well and faster. I think I just dove into this way to fast, trying run before I can even stand. LOL.



Yeah I think we (the proverbial car audio SQ community), should be working with them more on suggestions and improvements. I’ve talked to Andrew at Studio Six Digital before. Great guy. Possibly open for app improvement suggestions for the unique struggles we face in this silly hobby. 

So far, I’ve gotten pretty proficient with RTA, FFT and Transfer Function, and messed only a little with LARSA, which has as close as I’ve seen in Audiotools something like the ETC, IR and waterfall plots as we see them in REW. I think we should introduce those guys to Raimonds at APL Audio and get TDA in there. Imagine that kind of timing measurement power done from a silly iPad with a UMIK-1 attached and a headphone output to aux of system. Combine that with something robust for real time phase like Transfer Function, except that one needs some work... Take my money. 


Sent from my iPad using Tapatalk Pro


----------



## Durgesh

Babs said:


> I’ve taken a different approach lately. Rather than extensively and exhaustively interpreting and making major parametric decisions, I’ve backed off to old school.. Plain old 1/3 octave RTA. In audiotools I can pick any curve target txt file to tune to, then simply go at it, leveling and EQing individual drivers, then TA and phase so left side and right side match. I’ve done it a couple tries now and I tell ya, best image focus, stage size, separation and tonality I’ve ever been able to achieve in a very short amount of tuning time. As far as EQ goes, I for one am done with overthinking it. It’s real time with an RTA running on my iPad, while laptop is dedicated for the DSP. Works quick and gets it done.
> 
> 
> Sent from my iPad using Tapatalk Pro


How do you place the USB mic... at one place or take averages by moving the Mic ear to ear.

Sent from my SM-G950F using Tapatalk


----------



## AyOne

If I'm using my own EQ Filters can I get a smoother response with lower Q's? Say around 2 instead of 4.3? I'm asking this "generally" speaking. I saw a video someone posted about the JL TWK, I don't remember who, i noticed the Q's we're set around 1.3. So that made me wonder.


----------



## Hammer1

Q determines how wide or narrow the EQ band is. A setting of 0 will pretty well encompass the entire spectrum (depending on your gain) while a setting of 10 will only affect a very small range of frequencies. So using Q of a smaller number will help with a wider peak in your curve. The woes of tuning but atleast you have all winter before the next comp too really dial it in


----------



## Babs

Durgesh said:


> How do you place the USB mic... at one place or take averages by moving the Mic ear to ear.
> 
> Sent from my SM-G950F using Tapatalk


Yeah I've given up on multi-mic-position averaging for now seriously.. Until I can run a mic array properly in Smaart8, I'm just doing with what I have.. So there's the slow-go process of moving a mic in REW RTA, or multiple sweeps in REW measurement tool, which is even slower. Or there's instant gratification watching response change as I do it by just single-mic-position, AudioTools RTA or FFT on the iPad while the laptop is devoted just for the Helix DSP tool. I can say yes spatial averaging above the point of breakup (Schroeder frequency unique for your car) is in fact important. So after EQ work, I move the mic around a bit looking for something in mids and highs to jump out, then make decisions accordingly on strategic EQ work there.

It might not be ideal, but I'll tell you, just single mic, quick EQ work in my car at least, I was able to dial in a fairly good image that isn't drifting, wandering or ghosting, so it's in pretty decent balance I think.

And the best part is, changing to a different tonality curve is a matter of pulling it into AudioTools and just doing the process over with EQ and leveling. Process being 1) individual drivers, 2) pairs and sides, 3) overall.


----------



## Weightless

How do you add a target curve in AudioTools? I'm not seeing where to import...I really need to RTFM.

Sent from my SM-N920P using Tapatalk


----------



## Babs

Weightless said:


> How do you add a target curve in AudioTools? I'm not seeing where to import...I really need to RTFM.
> 
> Sent from my SM-N920P using Tapatalk


You can setup audiotools to talk to your dropbox.. Upload your curve file into the appropriate folder and then in app, download to the app to use for reference curve.


----------



## Babs

Sent from my iPhone using Tapatalk Pro


----------



## Weightless

Thanks man. Much appreciated. Im going to have to toy around with this for a bit.

Sent from my SM-N920P using Tapatalk


----------



## Truthunter

Babs said:


> Or there's instant gratification watching response change as I do it by just single-mic-position, AudioTools RTA or FFT on the iPad while the laptop is devoted just for the Helix DSP tool.


I've been wondering if REW could do this; RTA without constant averaging and maybe a response time adjustment to see real time eq changes. Been meaning to see if I can get it to work in this way but haven't had the time.


----------



## sq2k1

So when holding the mic near your head for measurements, the mic should point towards the windshield correct? It has been a while since I did this and I am having a major brain fart.....


----------



## bnae38

sq2k1 said:


> So when holding the mic near your head for measurements, the mic should point towards the windshield correct? It has been a while since I did this and I am having a major brain fart.....


Depends. Mic cal files from a cross spectrum umik (what I'm using) have 90degree (mic pointed up) cal files too.

Afaik it doesn't make a huuge difference though..


----------



## sq2k1

I am using a UMM-6 mic with a calibration file from Dayton Audio. I guess whether holding the mic on a horizontal or vertical plane would not have a serious impact considering you base measurements for what side of the car the speaker you are measuring is located. Using the 5/3 ratio for left side speakers and the 6/2 ratio for right side..... guess my brain fart has been expelled....thanks bnae.


----------



## stickybeak

May I request copy of the "31-band Graphic/Parametric EQ FILTER (DSP)"? The link shared by Hanatsu is returning an Error (429) _This link is temporarily disabled. The person who shared it hit their daily limit of traffic or downloads. Learn about traffic limits._

Thank you in advance!


----------



## subterFUSE

Mic cal files are not very important for Acoustic measurements. They are more aimed at the purpose of using a mic as a reference mic to calibrate other mics.

In fact, some of the most advanced measurement software like SysTune does not even have an option to load a cal file for a mic.

Also, in a car the cal file is less critical because of the close proximity of the mic to the speakers and the small size of the “room.”


Sent from my iPhone using Tapatalk


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## RRizz

Really?? I thought the cal file was to correct inaccuracies in the mics pickup response.
how do I trust that I'm getting true readings if the mic is not calibrated??
I think I will take some readings, and try again with the mic cal file deleted, and see what happens.... unless of course, the equipt isn't sensitive enough to detect those minor differences................


----------



## hockeythug

Very helpful info.


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## subterFUSE

Yup. Mic cal files are not necessary for car use. Even a cheap mic these days is going to be damn near ruler flat.


Sent from my iPhone using Tapatalk


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## hockeythug

Do you still need to put the crossover points into a filter for REW to work right? Was reading before I attempt to mess around with my C-DSP 6x8.

Think I found my answer in post #11

http://www.diymobileaudio.com/forum...cussion/333737-ta-channel-matching-c-dsp.html


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## steelwindmachine

For the scaling, is it at all helpful to set the frequency range to what you can actually hear based on a hearing test?

I intend to take a test soon, but I suspect I can't hear much if anything above 16KHz.

I would think that limiting the range to what you can actually hear would make the data collected more relevant and eliminate non-pertinent data.


----------



## jj8888

stickybeak said:


> May I request copy of the "31-band Graphic/Parametric EQ FILTER (DSP)"? The link shared by Hanatsu is returning an Error (429) _This link is temporarily disabled. The person who shared it hit their daily limit of traffic or downloads. Learn about traffic limits._
> 
> Thank you in advance!




May I request copy of the "31-band Graphic/Parametric EQ FILTER (DSP)" as well?


----------



## Iamsecond

What dsp are you guys using? I’m using a euphoria dsp which is a 31 band eq and I just set the filters i have in rew. 
Rew already has the settings if your using a mini dsp.


----------



## jj8888

Iamsecond said:


> What dsp are you guys using? I’m using a euphoria dsp which is a 31 band eq and I just set the filters i have in rew.
> Rew already has the settings if your using a mini dsp.


My DSP is P6.

Don't know how to carry out part 9 "Click here to load filter setting" without the filter "31-band Graphic/Parametric EQ FILTER (DSP)"


----------



## Iamsecond

Its actually pretty easy.

Open Rew Up and go through all the mic set up blah blah.

Now at the opening screen of rew you will see the rta and eq button.
Click the eq button. At the top you will see eq filters. Click that.
you will see 20 filter spots in different colors. Now, Under control pick manual, under type click PK and then under frequency put in each frequency your dsp uses and leave the gain and q alone.
I had to break mine up into three groups but two groups will be fine as you will see in a minute.
The first group I put 20 frequencies and the last one was the 20000. I think mine started at 315 or something like that. Anyway input all you can descending from 20000 and then click save, the icon beside the red X. Then label that tweeter or whatever you want to name it. Click X (AFTER YOU SAVE THE FILE) and clear the boxes and start at 20 hz and input 20 frequencyies that correspond to your dsp eq. after your done save that file as sub and mid. Whew, almost done lol.

Now, heres where it gets interesting. Close the eq filter window.

click the rta tab and take your measurement and save it. 

Click the eq button and click the eq filters button. It will probably come up blank. Thats fine.
Click the blue folder button beside the words NO MEASUREMENT and the sub/mid folder and your tweet folder will be there. Click which ever one you want and your filters will automatically be loaded. You should see them.

Now, on the window that you can see you saved rta plot, you will see FILTER TASKS on the right side. Click that. Set your settings but toward the bottom you will see MANUAL OPTIMISATION CONTROL. Click on the OPTIMISE GAINS AND Qs and your adjustments will show up in the eq filter window.

Its really easy once you do it a few times. I was pulling my hair out trying to figure this out but a few awesome guys on here explained it. Thanks guys.

Hope that helps.


----------



## Iamsecond

I may try and do a video to go along with skizers great video to help people like us who do not have a helix or parametric dsp. Mine is a 31 band paragraphic and its fine. Used it to flatten the rta response. Nick said his video is not for dsp like ours but 95% of his video is useful for both but with our type of dsp we have to set the available frequencies and go from there.


----------



## jj8888

Iamsecond said:


> Its actually pretty easy.
> 
> Open Rew Up and go through all the mic set up blah blah.
> 
> Now at the opening screen of rew you will see the rta and eq button.
> Click the eq button. At the top you will see eq filters. Click that.
> you will see 20 filter spots in different colors. Now, Under control pick manual, under type click PK and then under frequency put in each frequency your dsp uses and leave the gain and q alone.
> I had to break mine up into three groups but two groups will be fine as you will see in a minute.
> The first group I put 20 frequencies and the last one was the 20000. I think mine started at 315 or something like that. Anyway input all you can descending from 20000 and then click save, the icon beside the red X. Then label that tweeter or whatever you want to name it. Click X (AFTER YOU SAVE THE FILE) and clear the boxes and start at 20 hz and input 20 frequencyies that correspond to your dsp eq. after your done save that file as sub and mid. Whew, almost done lol.
> 
> Now, heres where it gets interesting. Close the eq filter window.
> 
> click the rta tab and take your measurement and save it.
> 
> Click the eq button and click the eq filters button. It will probably come up blank. Thats fine.
> Click the blue folder button beside the words NO MEASUREMENT and the sub/mid folder and your tweet folder will be there. Click which ever one you want and your filters will automatically be loaded. You should see them.
> 
> Now, on the window that you can see you saved rta plot, you will see FILTER TASKS on the right side. Click that. Set your settings but toward the bottom you will see MANUAL OPTIMISATION CONTROL. Click on the OPTIMISE GAINS AND Qs and your adjustments will show up in the eq filter window.
> 
> Its really easy once you do it a few times. I was pulling my hair out trying to figure this out but a few awesome guys on here explained it. Thanks guys.
> 
> Hope that helps.





Iamsecond said:


> I may try and do a video to go along with skizers great video to help people like us who do not have a helix or parametric dsp. Mine is a 31 band paragraphic and its fine. Used it to flatten the rta response. Nick said his video is not for dsp like ours but 95% of his video is useful for both but with our type of dsp we have to set the available frequencies and go from there.


Thanks for your reply and helps. I will try using your method.


----------



## ftmsmohan

I'm trying to set Crossover and EQ a subwoofer.
Could someone tell is it ok to hit EQ (Match respond to Target) now?
Or do i need to go much more closer? This is the best and closest that i can go nearer the RAW measurement. If can start EQ, can i try to match the range: 20hz~160hz (under the Filter Tasks-right side), i guess it's fine right?

*Crossover set electronically at DSP & REW Filter:*
20hz~80hz 24db LK

*Crossover set acoustically at REW:*
0hz~100hz 24db


----------



## Hanatsu

Measure and re-measure. Looks good otherwise


----------



## SilentWrath

So I've been playing around with my UMIK-1, REW and Dayton DSP-408 for the past month.

I've read a few guides on here about tuning, and downloaded Andy's guide as well.

Some things are still over my head but I've tweaked the EQ and Time Alignment and gotten it to sound pretty good to my untrained ears, at least better than it was without the dsp.

I'm still using the crossovers on my amps, 24db/oct at 80Hz on the sub and 12db/oct at 80Hz on the front stage, running the passive crossovers that came with my coaxial components (I think xover is 4.5kHz at 12db/oct).

I'm attaching a few pics from overlaying the RTA measurements. One pic shows RTAs overlaid of each individual driver, and the other shows the front stage playing together and the full system playing together.

I guess I'm just looking for any input at all.. good.. bad.. ugly.

Thanks!


----------



## bnae38

How does it sound?

That is a huuuge slope, wonder if a measurement oddity.. 

I have a similar looking curve, but 30db from low to high.


----------



## Hanatsu

SilentWrath said:


> So I've been playing around with my UMIK-1, REW and Dayton DSP-408 for the past month.
> 
> I've read a few guides on here about tuning, and downloaded Andy's guide as well.
> 
> Some things are still over my head but I've tweaked the EQ and Time Alignment and gotten it to sound pretty good to my untrained ears, at least better than it was without the dsp.
> 
> I'm still using the crossovers on my amps, 24db/oct at 80Hz on the sub and 12db/oct at 80Hz on the front stage, running the passive crossovers that came with my coaxial components (I think xover is 4.5kHz at 12db/oct).
> 
> I'm attaching a few pics from overlaying the RTA measurements. One pic shows RTAs overlaid of each individual driver, and the other shows the front stage playing together and the full system playing together.
> 
> I guess I'm just looking for any input at all.. good.. bad.. ugly.
> 
> Thanks!


Ignoring measurement method, based on that measurement - try,

*28Hz -6dB Q8
*Shelf filter at 50Hz pull down 8dB everything below 50Hz.
*320Hz -7dB Q4
*1400Hz -5dB Q3

Looks like too much in the lows, also in the lower midrange, 200-400Hz is too high compared to 500-1000Hz.


----------



## SilentWrath

bnae38 said:


> How does it sound?
> 
> That is a huuuge slope, wonder if a measurement oddity..
> 
> I have a similar looking curve, but 30db from low to high.


It doesn't sound bad at all, it is definitely a little bass heavy, but that is probably my personal preference to an extent.

I thought the 50db swing seemed a little too big by looking at it.



Hanatsu said:


> Ignoring measurement method, based on that measurement - try,
> 
> *28Hz -6dB Q8
> *Shelf filter at 50Hz pull down 8dB everything below 50Hz.
> *320Hz -7dB Q4
> *1400Hz -5dB Q3
> 
> Looks like too much in the lows, also in the lower midrange, 200-400Hz is too high compared to 500-1000Hz.


Thanks for the tips, I'll try those out this weekend!

If we don't ignore measurement method what other comments would you have?

I know the passive xovers are probably not ideal. I'm gonna wait till I make some sail panel pods to go active.


----------



## SilentWrath

After making the changes Hanatsu recommended as well as a few others here is where the full system RTA is at now.

Sounding better and better. Thanks, Hanatsu!


----------



## JCsAudio

Ouch! Way too much bass and lower mid bass. That must sound muffled. It’s always a matter of personal preference but I like it much flatter FR curve than that from 250 to 10k with the bass about 15 db more than what the mid woofer is playing and a slight taper after 10k Hz to 20K of about 4 db. I’ll see if I can post a graph of mine tomorrow when I have access to my laptop. I like the following as a starting point on my systems:

1) Sub LP Butterworth 24 db At 65 Hz (yes there is a gap but don’t worry)
2) Midbass HP Butterworth 80Hz 24 db and LP 24 db linkwitz Riley @ 3000 Hz or lower depending on tweeter.
3) Tweeter HP 24 db linkwitz Riley 3000 Hz depending on tweeters resonant frequency and ability to play without distortion.

Set time alignment for each driver by measuring in a straight line to each speaker and add for the distance from the cone to the center of the speakers coil. Ignore any obstructures like seats and if you cannot get the tape measure in a straight line to the speaker than estimate. Do not account for reflections.

Level match each driver separately so they play the same level left to right and then each side (tweeter and mid together) without the sub playing so they play equally left to right. Then add in the sub so it’s 12-15 db higher than the mid bass. You can also try a 12 db Butterworth LP on the sub and 12 db Butterworth on the midbass too if you have a clean playing sub with 1/2 octave between them.

EDIT: attached are those pictures. The purple is a truck and the blue and yellow is my small SUV. Both systems are active with JL Twk 88 DSP's. Both graphs are the same only one with 1/6 smoothing. Also at the very bottom is a stock Subaru Outback system so you can see how those engineers tune a stock system.


----------



## SilentWrath

Thank you for posting your RTA graphs and for your input in general.

I got some time to play around again this afternoon. Ended up cutting more out of 180 to 500 and getting rid of the amp crossovers to use the dsp butterworth 24db/oct at 70Hz for both front stage and sub.

Getting better and better I'd say. 

Once I ditch the passive xovers up front I will be able to clean it up a lot more, I've only got 10 peq filters for the front stage on each channel right now, once I go active I'll have access to 20 peq filters for each side of the front stage. 

Here's my graph now.


----------



## JCsAudio

Looking good! Once you go active and can time align each driver separately than it will really start to sound good to you. Don't be afraid to put a gap between the subwoofer and the midbass driver when playing the sub that high. The reasoning behind that is because you are playing the sub much louder than the midbass and this causes the acoustic crossover (not the electric one set in the DSP) to be higher than 70 Hz, because the sub is still playing after 70 Hz and just rolling off at 24 db per octave, which you see in your RTA also. When you put a gap between the HP and LP filters of those two drivers, you bring the actual acoustic crossover point closer to that 70-100 Hz point. You can see that in your RTA graph where the acoustic crossover point looks to be about 150 Hz. Granted, this may be what you prefer and that is ok, but just be aware that paying the sub that high isn’t the ideal situation for localization and its playing right into the male vocal range too. Since you have a DSP, you can save presets and go back to any tune you want so keep experimenting and having fun.

EDIT: see attached PDF


----------



## Ziggyrama

Curious, why BW xover? BW creates a 3db gain at the xover frequency and has lobing/cancellation problems across vertical axis. I suspect that is why you are suggesting asymmetrical filter points. LR is superior in every way. Depending on the driver placement in relation to his ears, he may have serious audible problem especially if he sits in the cancellation zone. FWIW.


V8toilet said:


> Ouch! Way too much bass and lower mid bass. That must sound muffled. It’s always a matter of personal preference but I like it much flatter FR curve than that from 250 to 10k with the bass about 15 db more than what the mid woofer is playing and a slight taper after 10k Hz to 20K of about 4 db. I’ll see if I can post a graph of mine tomorrow when I have access to my laptop. I like the following as a starting point on my systems:
> 
> 1) Sub LP Butterworth 24 db At 65 Hz (yes there is a gap but don’t worry)
> 2) Midbass HP Butterworth 80Hz 24 db and LP 24 db linkwitz Riley @ 3000 Hz or lower depending on tweeter.
> 3) Tweeter HP 24 db linkwitz Riley 3000 Hz depending on tweeters resonant frequency and ability to play without distortion.
> 
> Set time alignment for each driver by measuring in a straight line to each speaker and add for the distance from the cone to the center of the speakers coil. Ignore any obstructures like seats and if you cannot get the tape measure in a straight line to the speaker than estimate. Do not account for reflections.
> 
> Level match each driver separately so they play the same level left to right and then each side (tweeter and mid together) without the sub playing so they play equally left to right. Then add in the sub so it’s 12-15 db higher than the mid bass. You can also try a 12 db Butterworth LP on the sub and 12 db Butterworth on the midbass too if you have a clean playing sub with 1/2 octave between them.
> 
> EDIT: attached are those pictures. The purple is a truck and the blue and yellow is my small SUV. Both systems are active with JL Twk 88 DSP's. Both graphs are the same only one with 1/6 smoothing. Also at the very bottom is a stock Subaru Outback system so you can see how those engineers tune a stock system.


Sent from my Pixel using Tapatalk


----------



## JCsAudio

Ziggyrama, L-R is great when your levels for each driver are the same, such as between the tweeter and mid bass driver because the 6 db reduction at the xover point makes them cross over to each other at a level plane due to the Q of the L-R xover, plus they are in phase at that point. The trouble comes when you use a L-R xover and raise the sub level 12-15 db above the midbass level. If you use an 80 hz xover and raise the sub level higher, than the actual xover point (acoustical xover) will be much higher and the subwoofer will be playing into midbass frequencies, and the bass might be boomy or give you a headache. You will be reaching for that volume knob for sure to turn it down after a while. It will also be out of phase at that level. 

If you try to lower the xover to compensate, than the midbass woofers will be playing sub bass frequencies and the acoustical xover point will still be higher, likely 100 Hz or more and it just won’t be very cohesive. You will also be stressing your mid woofers at higher volume and cause distortion. With a L-R xover and a boosted sub volume you may have phase issues and get localization issues. If you just put a gap between the sub and midbass with a L-R xover, than you'll likely get a lull in the response due to the Q of a L-R xover because at the electrical xover, the frequency will be 6 db down at that point and out of phase. 

If you put ½ octave a gap between the sub and midbass with the sub at the same level as the midbass and use a shelf filter, than what usually happens is you get the acoustic xover to be at or below 100 Hz. The sub and midbass will be in phase with each other and actually boost the bass where you want it to be boosted and it will be cohesive and blend well with the midbass frequencies. If you have a DSP than you can try it, it works well for me.


----------



## ckirocz28

SilentWrath said:


> So I've been playing around with my UMIK-1, REW and Dayton DSP-408 for the past month.
> 
> I've read a few guides on here about tuning, and downloaded Andy's guide as well.
> 
> Some things are still over my head but I've tweaked the EQ and Time Alignment and gotten it to sound pretty good to my untrained ears, at least better than it was without the dsp.
> 
> I'm still using the crossovers on my amps, 24db/oct at 80Hz on the sub and 12db/oct at 80Hz on the front stage, running the passive crossovers that came with my coaxial components (I think xover is 4.5kHz at 12db/oct).
> 
> I'm attaching a few pics from overlaying the RTA measurements. One pic shows RTAs overlaid of each individual driver, and the other shows the front stage playing together and the full system playing together.
> 
> I guess I'm just looking for any input at all.. good.. bad.. ugly.
> 
> Thanks!


Based on that massive slope, I'm just guessing that you're NOT using one of the RTA settings in the RTA of REW. Click the gear icon in the top right corner of the RTA window and select one of the RTA measurements to use. I made this mistake when first using REW, I couldn't figure out why there was so much slope in my measurements.


----------



## Ziggyrama

Thanks for explaining. Essentially what you're doing is trying to achieve desired frequency response by using asymmetrical xover points. I think I get what you're doing.

That being said, I see a problem with that approach. By making your xovers asymmetrical, you are putting them out of phase, assuming you have then time aligned. Phase shifts with the frequency and xovers align at the center frequency. Once you move it, you are likely out of phase.

The problem you're describing of not having flat curve to tune to is pretty much everyone's problem. I believe everyone boosts low end to make it sound better. IMHO, it seems easier to define your FR curve, which isn't flat, start with LR4 which puts you in phase, that will define each driver's curve, apply the filter, and adjust any FR issues with EQ.

I think you're inviting more problem with asymmetrical xovers but if you think it works, roll with it. Asymmetrical xovers aren't a bad thing but they are usually used to correct for phase shifts due to driver offsets within an enclosure. My $0.02.



V8toilet said:


> Ziggyrama, L-R is great when your levels for each driver are the same, such as between the tweeter and mid bass driver because the 6 db reduction at the xover point makes them cross over to each other at a level plane due to the Q of the L-R xover, plus they are in phase at that point. The trouble comes when you use a L-R xover and raise the sub level 12-15 db above the midbass level. If you use an 80 hz xover and raise the sub level higher, than the actual xover point (acoustical xover) will be much higher and the subwoofer will be playing into midbass frequencies, and the bass might be boomy or give you a headache. You will be reaching for that volume knob for sure to turn it down after a while. It will also be out of phase at that level.
> 
> If you try to lower the xover to compensate, than the midbass woofers will be playing sub bass frequencies and the acoustical xover point will still be higher, likely 100 Hz or more and it just won’t be very cohesive. You will also be stressing your mid woofers at higher volume and cause distortion. With a L-R xover and a boosted sub volume you may have phase issues and get localization issues. If you just put a gap between the sub and midbass with a L-R xover, than you'll likely get a lull in the response due to the Q of a L-R xover because at the electrical xover, the frequency will be 6 db down at that point and out of phase.
> 
> If you put ½ octave a gap between the sub and midbass with the sub at the same level as the midbass and use a shelf filter, than what usually happens is you get the acoustic xover to be at or below 100 Hz. The sub and midbass will be in phase with each other and actually boost the bass where you want it to be boosted and it will be cohesive and blend well with the midbass frequencies. If you have a DSP than you can try it, it works well for me.


----------



## SilentWrath

ckirocz28 said:


> Based on that massive slope, I'm just guessing that you're NOT using one of the RTA settings in the RTA of REW. Click the gear icon in the top right corner of the RTA window and select one of the RTA measurements to use. I made this mistake when first using REW, I couldn't figure out why there was so much slope in my measurements.


Thank you for catching that!!!

I made a selection of RTA 1/48 oct. and it made a huge difference. I ended up having to remove some of the sub 200Hz cuts I made to the front stage, and now have the sub xover at 65Hz and front stage xover at 80Hz (both still 24db/oct BW). I also had to eq the sub down a little more around 45Hz to 50Hz.

I'd like to tame down 6.5kHz to 14kHz just a smidge, but I'm out of filters. It'll have to wait until I ditch the passive xovers in the front stage and go active and double the amount of filters I have access to for the front!

Anyways...

Here is where I'm at now with 1/6 oct. smoothing.


----------



## ckirocz28

SilentWrath said:


> Thank you for catching that!!!
> 
> I made a selection of RTA 1/48 oct. and it made a huge difference. I ended up having to remove some of the sub 200Hz cuts I made to the front stage, and now have the sub xover at 65Hz and front stage xover at 80Hz (both still 24db/oct BW). I also had to eq the sub down a little more around 45Hz to 50Hz.
> 
> I'd like to tame down 6.5kHz to 14kHz just a smidge, but I'm out of filters. It'll have to wait until I ditch the passive xovers in the front stage and go active and double the amount of filters I have access to for the front!
> 
> Anyways...
> 
> Here is where I'm at now with 1/6 oct. smoothing.


That's looking pretty good. Maybe some head unit eq can tame that last peak.


----------



## SilentWrath

ckirocz28 said:


> That's looking pretty good. Maybe some head unit eq can tame that last peak.


Took the HU treble down 2 and that helped a bunch, and also adjusted xovers a little bit more. Sub at 56Hz front stage at 75Hz (both 24db/oct BW).[Green line]

Then took a little out of the bottom end 35-60Hz..mostly at 45Hz. [Blue line] I have one preset saved without those cuts when I want a little more bass.

[Red line is yesterday's tune]


----------



## ckirocz28

SilentWrath said:


> Took the HU treble down 2 and that helped a bunch, and also adjusted xovers a little bit more. Sub at 56Hz front stage at 75Hz (both 24db/oct BW).[Green line]
> 
> Then took a little out of the bottom end 35-60Hz..mostly at 45Hz. [Blue line] I have one preset saved without those cuts when I want a little more bass.
> 
> [Red line is yesterday's tune]


I could live with that.


----------



## ckirocz28

SilentWrath said:


> Took the HU treble down 2 and that helped a bunch, and also adjusted xovers a little bit more. Sub at 56Hz front stage at 75Hz (both 24db/oct BW).[Green line]
> 
> Then took a little out of the bottom end 35-60Hz..mostly at 45Hz. [Blue line] I have one preset saved without those cuts when I want a little more bass.
> 
> [Red line is yesterday's tune]


For future reference, if you need to boost or cut over a really broad range you could use opposing high or low shelf filters if you have them. I had to use a high shelf at 90 hz +9db and a high shelf at 180 hz -9 db to add some midbass impact, the upper one cancels the lower one after 180 hz. Kind of a bandpass filter, cobbled together. DSP's can be really flexible, sometimes only limited by your imagination.


----------



## jj8888

I'm using Hertz Mille Pro163.3 and Helix p6 dsp mkii. The following are the measurement curve with REW, it's look odds, can anyone help to check what's wrong?

Right Midrange:









Left Midrange









Left subwoofer:









Right subwoofer:









Left Tweeter:









Right Tweeter:









Crossover:










Please ignore my bad English.:shrug:


----------



## sareea

jj8888 said:


> I'm using Hertz Mille Pro163.3 and Helix p6 dsp mkii. The following are the measurement curve with REW, it's look odds, can anyone help to check what's wrong?
> 
> Right Midrange:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left Midrange
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left subwoofer:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Right subwoofer:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left Tweeter:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Right Tweeter:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Crossover:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Please ignore my bad English.:shrug:


It would be easier to help if you put images of pairs
Left and right tweeter in the same graph etc for mids and midbass. 

It would be great if you put left channel (tweet and mid and midbass measured together for the left side ) measurement vs right channel measurement.


----------



## jj8888

Thanks for looking.

Please help to check the following:

Left_Right Tweeter:









Left-right Midrange:









Left_Right Sub-Woofer:









Left:









Right:


----------



## sareea

jj8888 said:


> Thanks for looking.
> 
> Please help to check the following:
> 
> Left_Right Tweeter:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left-right Midrange:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left_Right Sub-Woofer:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Right:


I see major problem in gains between l and r sides. 
Please put the L and the R channel graphs in 1 graph. 
And it qould be easier if you use graph smoothing, At least 1/12. 
Even 1/6 for tweets. 

Sorry forgot to ask few more questions, 
How is tour system connected? Active ?
What are the xo points and slopes and xo type. 
What have you already done in tuning ? Is this after equalization ?


----------



## jj8888

Hi Sareea,

Thanks for your reply.

I have active set-up, Tweeter and midrange are on the A pillar, Subwoofer are door mounted. 

This setting is copied from my installer, stage position is ok but sound flat and unsatisfied. I reset the equalize and try tuning. 

XOs (both left and right):
Tweeter









Mid:









Subwoofer:










Not very sure XO Typeis this you're referring to?)









Left_Right Midrange:









Left_Right subwoofer:









Left_Right Tweeter:










Left_Right channel:


----------



## sareea

jj8888 said:


> Hi Sareea,
> 
> Thanks for your reply.
> 
> I have active set-up, Tweeter and midrange are on the A pillar, Subwoofer are door mounted.
> 
> This setting is copied from my installer, stage position is ok but sound flat and unsatisfied. I reset the equalize and try tuning.
> 
> XOs (both left and right):
> Tweeter
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Mid:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Subwoofer:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Not very sure XO Typeis this you're referring to?)
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left_Right Midrange:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left_Right subwoofer:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left_Right Tweeter:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Left_Right channel:



I guess what you mean by sub woofer as midbass  
or no ?

I understand from you that a tuner has already flattened the system, and you didn't like the flat sound. 
I suggest instead of making everything from the start:
go back to the tuner's settings ( the flat that you didn't like ).
Then tune the tonality for your likings from the headunit main EQ, or the Helix input EQ also possible. 

The DSP comes to fix the room effects on speakers, after you fix it ( flattening the system) you tune for your likings.. 

Try this approach first. It would cost you a lot much lesser time. 

In case you wanted to continue tuning yourself from the beginning:
1. Use Hanatsu's recommended settings for XO, use Linkwetz riley 24 db slope on everything. 
regarding what frequencies to cut, I had once mille pro 165.2, and didn't like the midbass at all, it gave me ear fatigue all the time so I would keep it 100-500~ as you did. In short, keep the current frequencies.

2. I see you already measured each speaker in your system ( and I am assuming you did multiple points SWEEPS (use sweeps!) averages as Hanatsu recommends). 
for each speaker measurement make the average and go to AutoEq in REW and find the frequencies for the equalizer ( in case you need help there Hanatsu has made another thread for this I guess )
and input it in Helix.

3. Now you "fixed" each speaker's Frequency Response, with the hertz speakers I guess you need multiple measurements and EQ for each speaker ( from my experience as the Hertz aren't easily compliant for EQ changes)

4. You need to match the gains between pairs. Both tweeters must be the same volume\gain to you ears. and then match the gains between components tweets to mids etc (do this according to the curve you are EQing to)

5. Validate the phases. And do the Time alignment (measure with a tape and input the distances in Helix, then fine tune the timedelay by millesecends). 
For this step I use mono pink noise, the correct sound must come out of the center of the dash, and not from the front of the driver as many says.


so, XO, phase, gains, and EQ are all done, it should sound good, and tune for you liking by the main headunit EQ or the helix input... That is a basic tune I guess. After that you continue to search for the left 2%


----------



## jj8888

sareea said:


> I guess what you mean by sub woofer as midbass
> or no ?
> 
> I understand from you that a tuner has already flattened the system, and you didn't like the flat sound.
> I suggest instead of making everything from the start:
> go back to the tuner's settings ( the flat that you didn't like ).
> Then tune the tonality for your likings from the headunit main EQ, or the Helix input EQ also possible.
> 
> The DSP comes to fix the room effects on speakers, after you fix it ( flattening the system) you tune for your likings..
> 
> Try this approach first. It would cost you a lot much lesser time.
> 
> In case you wanted to continue tuning yourself from the beginning:
> 1. Use Hanatsu's recommended settings for XO, use Linkwetz riley 24 db slope on everything.
> regarding what frequencies to cut, I had once mille pro 165.2, and didn't like the midbass at all, it gave me ear fatigue all the time so I would keep it 100-500~ as you did. In short, keep the current frequencies.
> 
> 2. I see you already measured each speaker in your system ( and I am assuming you did multiple points SWEEPS (use sweeps!) averages as Hanatsu recommends).
> for each speaker measurement make the average and go to AutoEq in REW and find the frequencies for the equalizer ( in case you need help there Hanatsu has made another thread for this I guess )
> and input it in Helix.
> 
> 3. Now you "fixed" each speaker's Frequency Response, with the hertz speakers I guess you need multiple measurements and EQ for each speaker ( from my experience as the Hertz aren't easily compliant for EQ changes)
> 
> 4. You need to match the gains between pairs. Both tweeters must be the same volume\gain to you ears. and then match the gains between components tweets to mids etc (do this according to the curve you are EQing to)
> 
> 5. Validate the phases. And do the Time alignment (measure with a tape and input the distances in Helix, then fine tune the timedelay by millesecends).
> For this step I use mono pink noise, the correct sound must come out of the center of the dash, and not from the front of the driver as many says.
> 
> 
> so, XO, phase, gains, and EQ are all done, it should sound good, and tune for you liking by the main headunit EQ or the helix input... That is a basic tune I guess. After that you continue to search for the left 2%


Thank you for your time, advises and suggestions, appreciate that.


----------



## jj8888

Btw, any good recommendation for mille pro midbass replacement?


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## SilentWrath

Here's where I'm at today. Sounds fantastic, probably a bit bass heavy for some, but hey, there's a bass knob for that.


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## ckirocz28

Multiple measurements averaged together is absolutely key. Not the new "Vector Average", the standard average from the button in the plot window lower left. Sweeps or rta doesn't matter, just multiples averaged.


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## compuwiz1937

I'm very confused on how to choose the proper crossover frequency and where to put those frequencies in REW. I believe I understand the acoustic crossover is where I bring up the subwoofer, mids, and tweeters and see where the actual frequency response crosses or where it obviously drops off and that's the number I put into the "target setting" box. But where do I go from there? I tried playing with the LP and HP numbers with manual settings under the "EQ Filters" tab but I'm not really getting it to line up well with the target response line. Actually what I type in the target response box seems to get the line to match the best and when I try and do the manual ones in the filters tab it makes it worse. I can raise the target level by raising the cutoff Hz does that mean anything? Unless I'm interpreting all this wrong.

Here's what I'm starting with. My thoughts on the acoustic crossovers are: 
Sub: LP at 60Hz, HP at 20Hz.
Mids: LP at 2800Hz, HP at 39Hz.
Tweeters: HP at 2250Hz.

I might have the tweeters a bit too loud though or the woofers aren't loud enough. One other thing I was curious about and I'm not sure if this is the right place to ask but I don't feel it deserves it's own thread, can I raise my gains slightly after EQ? I set them with 50Hz and 1kHz test tones and a DMM so if it was brought down at those frequencies I don't see why I couldn't?


----------



## preston

Frankly I've never really understood why one sets x-over frequencies in REW ? I set my xover's where I want them, and then when I do pink noise/freq sweeps if it isn't smooth or flat at those frequencies I'll just adjust one of them lower or higher until any bumps are removed. (You can also play with slopes, but I've been wary of that since it starts altering phase (at the xover point) which begins to have effects I can't really understand, whereas the reason Linkwitz-Reilly 24db/octave slopes are recommended is because it maintains phase at the x-over point). 

I'm not really sure what your'e showing in your attached graph, are those sweeps of your full system or is each line supposed to be a driver and if so why do they cover the whole spectrum ? 

as far as gains yes don't sweat it, change your gains as you like to get the match you want. No need to be super strict - I mean yeah a competition system or one where you absolutely want to have your max volume correspond exactly to 1 mV below clipping I guess, but you don't need to be scared of it. I adjust my different driver gains all the time, usually by ear after I tune the system for awhile. 

As far as setting xovers I like to pick a basic region, but its worth while muting all drivers except one pair and playing with how they sound at varios xover frequencies - I'm usually more concerned with the LP then the HP, as the HP will be set to match the LP of the next higher driver. For example I like to set my midrange as low as feasible because I like it that way, but at high volumes this will add more distortion to the midrange- but I don't listen at super high volumes. So I will play with the LP on the midrange at mid to high volume to make sure it sounds good and then set the LP as low as I dare (which always ends up around 250Hz anyway ha ha). 

And don't let the graph dictate to much what sounds good to you either, always tune by ear in the end. 

But I"m no expert, just some suggestions from another enthusiast. If I didn't get your question let me know.


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## compuwiz1937

Ok, I was only doing it because this guide said to. I understand there are multiple ways to skin this cat, I’m just the type of person that likes there to be only one right way because it’s easier to accomplish! And this being the first system I’ve ever had a DSP for and tried to tune it also adds to the fun. So how do you do the autoEQ function? Just type in whatever target frequency to get the target line to resemble the frequency response measured? Do you decide on the crossover points and then make all new measurements before doing the autoEQ?

That graph is my averages measurements of all the speakers with no crossovers on (except a 1950Hz HP to protect them from the lows). I wasn’t sure if at least starting with the frequency they naturally cross at was correct or not. So if you cross the mids at say 3000 Hz the you should have the tweeters cross at 3000Hz? That was another question I had that I forgot to ask if there was any point to overlapping the crossover points like I mentioned above crossing the mids at 2800Hz but having the tweeters cross at 2250Hz.


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## preston

In my experience you are more likely to separate the xover points then overlap them. Using 24db/Octave LR slopes, in theory the xover for two speakers should be the same value, in your example 2800Hz. This generally works more exactly for higher range speakers, between the sub and the woofer its common to leave a gap, or even use a 12db slope for the sub to help it blend better but again only if you leave a gap say 80Hz for the LP of the sub and 100Hz for the Hp of the woofer. REW will tell you the answer here, as the slope should be smooth and even at the xover point and not have an obvious dip or bump. 

I never trust the auto EQ function myself I'm sure it works well if you follow all the instructions but where I struggle with tuning is that the response is never a straightforward curve -whether you use averages or pink noise it can get confusing. I just run pink noise and tune out bumps and small dips in real time that way I can actually see what I'm doing on the screen. I will then move the mic a little bit around to see how it affects my final curve and if I missed something or tuned something that wasn't there. I find it almost impossible to run sweeps, average, adjust eq, and then run sweeps again its just too hard to dial it in although that does work but after about 6 cycles of this I get tired of it. But that's me, setting up autoEQ in REW probably does dial things in more accurately especially in terms of what Q any given eq band uses. Doing it manually maybe gives you a better feel for things too.

One more thing I do after setting EQ, I listen to my reference music and will actually go in and adjust bands that ended up with a lot of EQ like -8db or +3db (try to never use more than 3 db boost), and I will play with those bands a little bit reducing the amount of eq and determining what I think. Sometimes it sounds better to me to have less EQ even if REW says I need it. People always talk about not being afraid of using too much cut wher eyou need it but EQ is adding its own phase shifts etc. to the music and you're better off with a little bit more ragged freq than a giant whack to the signal. IMO of course.


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## compuwiz1937

Interesting. I guess I've got some more stuff to play with then. What's funny is I did a rough tune on my truck so it would sound decent for our trip after Christmas and I didn't put much effort into it because I have a different subwoofer for it and it turned out better than I expected. I did my car the same way and while it doesn't sound terrible, I can tell it could sound better but I think the crossovers may have a lot to do with it rather than the EQ. Just goes to show every car is different.

I'll have to play with the pink noise again because I thought I had read you could do live reading/adjustment with it but I thought I was doing it wrong. It didn't show anything until I stopped the recording. Is that how it's supposed to be? Just live-ish?

Does the volume at which I make the measurements matter? Or just that it's consitent for all the measurements?


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## stixzerjan

Hi guys, i have been playing with Rew quiet some time now. I just have the same question to confirm, does the volume level in dB will affect the end result. I found that it will, especially in the upper midrange and hi. Thanks for feedback. 

Sent from my ASUS_Z00AD using Tapatalk


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## subterFUSE

preston said:


> People always talk about not being afraid of using too much cut wher eyou need it but EQ is adding its own phase shifts etc. to the music and you're better off with a little bit more ragged freq than a giant whack to the signal. IMO of course.



If the EQ applied is resulting in flatter frequency response, then the phase shifts that accompany the EQ will actually be a good thing, not bad.

Flat frequency response yields smooth phase response.

It’s when the frequency response is not smooth and flat that the phase shifts will be more harsh. Large peaks or dips in response will have bad phase shifts.



Sent from my iPhone using Tapatalk


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## SkizeR

subterFUSE said:


> If the EQ applied is resulting in flatter frequency response, then the phase shifts that accompany the EQ will actually be a good thing, not bad.
> 
> Flat frequency response yields smooth phase response.
> 
> It’s when the frequency response is not smooth and flat that the phase shifts will be more harsh. Large peaks or dips in response will have bad phase shifts.
> 
> 
> 
> Sent from my iPhone using Tapatalk


this. a given frequency response have a given phase response. when your fixing frequency response, your ALSO fixing the phase.


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## preston

Interesting. I'm not nearly the expert you guys are so I'm not arguing with you, but....You are measuring the Freq from a microphone at an averaged point in the car. When you apply EQ you are molesting the electronic signal. It seems a bit optimistic to think that as it translates through to the speaker and the air waves that it all comes back into sync without any "distortion" (I'm using that word colloquially) even if REW now says its flat. 

I think we would agree that less molestation of the electronic signal would be ideal. I've just found I prefer keeping my cuts to 6dB or less regardless of what REW says. Sometimes I'll cut a little adjacent or modify the Q to reach my goals instead. But I'm not an expert and have never worked with an expert so maybe I have other issues like how I interpret the graphs or my measurement methods or what else. I only know what I like to hear !

I actually have a BSEE degree from back in '89 although I was never that good of an electrical engineer, but I don't really understand this "when your fixing frequency response, your ALSO fixing the phase." Not sure we need to dive into that discussion though unless you have a simple way to illustrate that.


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## Jscoyne2

Its really not that hard to grasp. An electric signal is completely different than the acoustic one.

Say i give my speaker a flat 20-20khz signal from phone to the amp through an aux to rca cable. (Ignore any ideas about phone eq affecting anything.) 

The speaker is going to receive that flat signal and then all the speaker parts start to come into play and the speaker plays music. The T/S specs, the cone break up, the enclosure, the room acoustics, the resonances of everything around it. 

Soundwaves are flying around. 

Now the mic comes into play. You can measure a single spot. Anywhere in the car and the response will be different. 

Flat signal electrical, wildly different acoustic response.

So how do we fix that. A DSP. 

So lets over simplify. Lets ignore 99% of whats going on in a vehicle and just say that you give a speaker a flat signal and you're measuring at the headrest, a single spot.. You get a 5db bump at 500hz. Everything else on response is totally flat.

How do we fix that? Well. You modify the electrical signal so that it has the inverse of that 5db 500hz bump. (A parametric filter .The headrest will now measure flat.

Now throw everything about physics back in and add high pass and low pass and 31 bands of eq per driver and t/a and all pass filters and spatial averaging, and you can see why dsps are necessary and "molesting" the signal is necessary.




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## preston

You mis-interpret me. I'm not saying don't use EQ, and I understand why we do it. I'm saying that the acoustic energy in the room/car is "elastic" in the sense that things are reflecting and bouncing all over the place and moving a mic a few inches this way and that can change what you are measuring. Its not like there is this perfect mathematical summation/resolution between the EQ applied to the signal and the acoustical signal. Its always been one of the primary pursuits of audiophilism, the attempt to reduce as much as possible those things that affect the pure signal. You don't see home audio so focused on active x-overs and EQ because they dont face the problems we do in a vehicle. I'm just saying that while we have to tame the acoustic response, there are tradeoffs and when you have a big boost/cut that tradeoff may be to not push that slider down all the way until your REW looks like a dream. And maybe I'm wrong about that, I've never worked with an expert pair of ears, I've just found that if I have a tuning session where I've made a lot of drastic cuts or boosts, if I go back through and listen to music, i sometimes find it sounds better smoothing out some of that EQ. Not going to flat, but just not getting crazy with the sliders.


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## SkizeR

Your right. reflections and whatnot are going to cause issues with the response and phase, BUT.. if you measure a single driver, its phase response is fully correlated to the frequency response. They go hand in hand. So when you are correcting frequency response you are ALSO correcting the phase response. Of course there are some situations where things arent as predictable because of the f'd up nature of a car, but its usually nothing to worry about. fix the frequency response.


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## compuwiz1937

I ended up painting last weekend and did not touch my system at all like I had planned. I've changed the crossovers around just to try it but nothing else. Maybe this weekend. I want to give the AutoEQ a try before giving it a go myself especially so I can learn more about using REW. Should I take new measurements with the crossovers I've selected and then to the AUtoEQ based on that or should I use the measurements that have no processing? Or is this another try it both ways and see which works better scenario?


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## diy_darryl

Is this tutorial consolidated somewhere? 

I am drowning in all the info spread out over so many pages. First time REW user, actually just got my UMIK-1 in the mail so trying to figure it all out.


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## ominous

diy_darryl said:


> Is this tutorial consolidated somewhere?
> 
> I am drowning in all the info spread out over so many pages. First time REW user, actually just got my UMIK-1 in the mail so trying to figure it all out.


Someone consolidated all Hanatsu's post into one guide. I've got it on my personal laptop (I'm at work right now). I'll post it again for those that want it when I get home, but I'm pretty sure the original is somewhere in this post.


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## diy_darryl

ominous said:


> Someone consolidated all Hanatsu's post into one guide. I've got it on my personal laptop (I'm at work right now). I'll post it again for those that want it when I get home, but I'm pretty sure the original is somewhere in this post.


Thank You! I thought I read all 18 pages but must have missed it somehow.


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## ominous

diy_darryl said:


> Thank You! I thought I read all 18 pages but must have missed it somehow.


Here you go.


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## thornygravy

ominous said:


> Here you go.


Damn, you da man! thanks


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## flgfish

thornygravy said:


> Damn, you da man! thanks


The house curve link on page 10 is dead... anyone have a copy they can put up here? Thanks!


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## ckirocz28

flgfish said:


> The house curve link on page 10 is dead... anyone have a copy they can put up here? Thanks!


If it's the generic target curve in post #45, this is it. (copy and paste into text file)
20 13
50 10
80 7
120 4
200 0
500 -1
1000 -2
2000 -5
4000 -8
10000 -13
20000 -15


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## senile32nd

used this thread to run sweeps instead of pink noise as i was having a hard time and it has worked out well... i think lol, new to this and i dont know anyone around st pete that i can bother for help..

let me know what you guys think and if i need more attention in certain areas. using SI 3 way with a SI 3.5 for center as well in 2015 f150 plat. hence why the 1500 mark is so high i think.


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## senile32nd

simpler over all view


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## bnae38

Post graphs in 5db per vertical division and 6db or var smoothing plz


Looks like a good start. Might need to tweak levels on some drivers.


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## senile32nd

graph showing FRFL Woofers combined FRFL mid drivers combined, FR tweeters an FL tweeters separate, SubWoofer and Center channel. All with Var smoothing and 5 DB vertical graph


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## SilentWrath

Looks like you've got a great start. I'd adjust tweeter levels to match a bit closer. One side appears to be 5db louder, shouldn't be too difficult to bring that down to match.


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## dumdum

Justin Zazzi said:


> Great work Hanatsu, I really look forward to seeing this develop further.
> 
> Do you plan to talk about connecting the 2nd channel in a "loopback" configuration? I find it is exceptionally useful for time alignment.


Sorry to tag you Justin, can you provide a picture of how to cable up an interface for loopback measurement (or point me towards somewhere that has one), I have an m-audio usb mobile preamp on its way to me as I type and a Dayton mic as the current Behringer ones don’t get decent reviews...

I want to specifically do just what you speak of...

Or the same question for hanatsu...

I’ve seen various guides and I believe it’s routing the output of the device that comes from the left channel into the right channels input or something like that so it can see when it’s timing pulse is sent out and compare that to when it sees it on the mic and effectively zero that so you just get an accurate time of the impulse

Also what do you use for impulse response? Rew or holm?


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## bbfoto

dumdum said:


> Sorry to tag you Justin, can you provide a picture of how to cable up an interface for loopback measurement (or point me towards somewhere that has one), I have an m-audio usb mobile preamp on its way to me as I type and a Dayton mic as the current Behringer ones don’t get decent reviews...
> 
> I want to specifically do just what you speak of...
> 
> Or the same question for hanatsu...
> 
> I’ve seen various guides and I believe it’s routing the output of the device that comes from the left channel into the right channels input or something like that so it can see when it’s timing pulse is sent out and compare that to when it sees it on the mic and effectively zero that so you just get an accurate time of the impulse
> 
> Also what do you use for impulse response? Rew or holm?


If your using a USB mic I think you'll need to use HOLMImpulse because REW will not do time-domain via USB from what I remember.

Also, I think _subterFUSE_ posted a napkin sketch flowchart of a basic loopback setup earlier in the thread. But yes, you basically take an output from your audio interface and route it back to another input.


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## Facel

Hanatsu said:


> I'm aware of that little issue. If you use the 1/3oct spaced filters I provided and generate EQ filters with 'Optimize Frequencies, Gain, Qs' instead of full auto it will generate filters that's at 10% +/- of the 1/3oct standard octave spacing which the Helix handles fine


Great post Hanatsu - Thank you so much

Where can I get your "31 band graphic/parametric EQ Filter" file in order to use with a Match DSP (Same DSP tool as the Helix) ?
(the link does not respond anymore)


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## DonGato

Facel said:


> Great post Hanatsu - Thank you so much
> 
> 
> 
> Where can I get your "31 band graphic/parametric EQ Filter" file in order to use with a Match DSP (Same DSP tool as the Helix) ?
> 
> (the link does not respond anymore)




I would like to know also


Enviado desde mi iPhone utilizando Tapatalk


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## 72c10

Using this guide. When setting my filters before autoeq, they’re all set at 10 on the q. My dayton dsp default is 2.515. Do I set all of the Qs to that or leave them alone?

Also the dayton is a 10 band. Do i take the high and low frequency of the driver im tuning between the xover and divide that by 10 and set my targets there for the pre auto eq points? Or just line em up normal on what I can fit? This is a 2 way setup, so ive got more than 10 bands on the mids and highs.


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## 72c10

Just tried again. Attaching all my auto eq curves...plugged them in and it sounds absolutely horrible...

Started over completely with pink noise and did each driver at a time. Then level matched and adjusted to as close to the curve as possible. Decent, but nowhere near where it could be.

Running pink noise through rew, L&R channel -22db
With the built in generator and my mic wont read anything over 10,000hz...

I got no idea what’s going on.
















Im so tired of getting ear fatigue and having a headache from doing this. My ears burn.




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## 72c10

Figured out my mic problem


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## jtrosky

What was the mic problem (and solution)?

Those auto-eq values sure do seem strange. I don't think I've ever had REW recommend all filters with the exact same dB and Q values like that? 

I haven't read back through the thread yet, but will do that now (curious to see actual measurement graphs, etc).

I will say this - as another noob to all of this SQ tuning and DSP stuff, I've found that tuning to a target curve produces very different sound than what I was used to with just setting a regular graphic EQ to the "smiley face" pattern, like I've always done before. I think that folks like us are used to over-emphasized bass and treble, so a "technically correct" system sounds a little flat and lifeless in comparison. 

I would get things tuned in to be "technically correct" - and make sure the left and right sides match as much as possible and then use some sort of "global" EQ to adjust for preference. Or - you can create your own target curve to include some extra emphasis on bass and treble, for example (or whatever your preference is).

EDIT: actually, I don't see any graphs posted - can you post some graphs of what your system currently looks like? Actually, you really should start your own thread for this discussion since it's not really specific to Jazzi's tool....


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## 72c10

This thread isn’t about jazzi’s tool...

Range for pink noise was cutoff for some reason in the program.

I made a new set of filters relates to my dsp and load those now when using auto eq and select optimize q, gain and freq now.

I think my major problem is I need to add a 2.5” mid more focused to the driver seat.

Mids are mounted in the bottom of the doors and they fire directly at each other. My head is way off axis from the driver side.


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## jtrosky

72c10 said:


> This thread isn’t about jazzi’s tool...
> 
> Range for pink noise was cutoff for some reason in the program.
> 
> I made a new set of filters relates to my dsp and load those now when using auto eq and select optimize q, gain and freq now.
> 
> I think my major problem is I need to add a 2.5” mid more focused to the driver seat.
> 
> Mids are mounted in the bottom of the doors and they fire directly at each other. My head is way off axis from the driver side.
> 
> 
> Sent from my iPhone using Tapatalk


My bad - not Jazzi's tool (not sure why I said that!) - but I'm just saying that you'd probably get better/more focused feedback/help if you started your own thread - otherwise, there will end up being lots of un-related posts that get in between your posts and posts responding to you - and it can become hard to follow in a general "how-to" thread, that's all... 

You should be able to get good sound quality even when using the factory speaker locations. You can definitely get better than "sounds like crap".  Customizing the speaker locations, angles, etc is great and can definitely make things better, but there are a lot of people with great sounding systems using factory speaker locations. I don't think that is your main "bottleneck" right now - at least based on your descriptions of your issues.


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## PamSilver

Thanks for sharing much useful info


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## Swordsman

In a 3-way setup and a subwoofer. Do you need to turn the gain on the sub up 6db after all the eq done? I assume for a single subwoofer to support L-R channel bass, it will need more output.


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## rockinridgeline

Swordsman said:


> In a 3-way setup and a subwoofer. Do you need to turn the gain on the sub up 6db after all the eq done? I assume for a single subwoofer to support L-R channel bass, it will need more output.


If you have a single sub there are two ways of handling it. one is to use one channel of input when you are matching the sub output to each side. Reducing the input by 50% while matching each side accomplishes the same thing. The other is to increase the gain on the sub to level match both channels playing at the same time. either one works. hope this helps.


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## Aqua

New to this forum and I am also a new user of REW. I am from Sweden so my english is not the best.

I am trying to measuring my new build car audio setup but have got into problem after the maesurment are done and I am about to put EQ filters to all the curves. The speakers are measured individually.

All of the curves have a big slope from +30db down to -10db. It looks really strange and I belive some of the settings are wrong. I am using an UMIK-1 toghether with a calibration file when I make those measurments.

What do you think about this curve? Maybe everything is ok but for me it looks weird.

I also have a big dip In on both the mids that already starts at 300hz even though the crossover are set to 80hz at the HPF and 3000hz at the LPF with a 24db LR filter.


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## WinWiz

Aqua said:


> New to this forum and I am also a new user of REW. I am from Sweden so my english is not the best.
> 
> I am trying to measuring my new build car audio setup but have got into problem after the maesurment are done and I am about to put EQ filters to all the curves. The speakers are measured individually.
> 
> All of the curves have a big slope from +30db down to -10db. It looks really strange and I belive some of the settings are wrong. I am using an UMIK-1 toghether with a calibration file when I make those measurments.
> 
> What do you think about this curve? Maybe everything is ok but for me it looks weird.
> 
> I also have a big dip In on both the mids that already starts at 300hz even though the crossover are set to 80hz at the HPF and 3000hz at the LPF with a 24db LR filter.
> 
> View attachment 297097


What kind of system do you have? Looking at the graph I'm guessing 3 way + sub? All active?
It kind of looks like your tweeters are playing 40dB at 8hz! Or maybe it's full range drivers? Don't you have a high pass filter on the tweeters??
I suggest you adjust your crossovers and level match the speakers before equalizing...


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## Aqua

Thanks for replaying.

The system contains of.
1. HU: OEM stereo VW Polo 2016
2. DSP: Helix DSP.3
3. Amp for front: Nakamichi NGXA 120.4
4. 6.5” Mids: Rainbow Germanium GL-W6
5. Tweeters: Rainbow Germanium GL-T6
6. Amp for rear: Ground Zero GZTA 2255X-B
7. Rear speakers: Ground Zero GZRF 6.5SQ
8. Amp for SUB: Nakamichi NGXD 1600.1
9. Sub: Rainbow Germanium GL-S12

Crossover points.
Tweeters: HPF 3000Hz, LPF 20.000Hz with a 24db LR filter

Mids: HPF 80Hz, LPF 3000Hz with a 24db LR filter

Rear 6.5”: HPF 300Hz, LPF 3000hz with a 24db LR filter.

Sub: HPF 25Hz, LPF 80Hz with a 24db LR filter.


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## WinWiz

I'm guessing the the red and the green line that plays way louder than anything else from 3-15KHz is the coaxial speakers in the back of your car?
Where are your front mid-drivers located in the car?
Did you time align before these measurements?


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## Aqua

The green and red curves are from the tweeters. The mid drivers are located in the doors where the original speakers where located. Time Alignment where made before this measurement.


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## WinWiz

Your x-overs doesn't seem set like you wrote. So I suggest that you check the settings in helix software. If your amps have x-overs make sure they are disabled.

I would also suggest that you limit the frequency range when you measure the response. Your mic isn't accurate at extreme low/high frequencies. So something like 2k-20khz for the tweeters and 20hz-20khz for all the other speakers.

You sub looks awfully peaky so I would ditch the 25hz hipass filter -but compared to all the other issue that's a minor problem...

If you are unsure how to use the helix software it might be worthwhile to test different settings with only the coaxial speakers running -so you can verify that you settings work the way you expect without risking to blow a tweeter...


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## Aqua

I agree with you completely but the crossover are set as I have mentioned and thats why I write this post. I have no crossover set at the amplifiers at all. Everyone are set to full range because of the DSP. I really should have someone near that could have a check. 😊


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## WinWiz

I updated my previous post while you replied.
Oem headunit... So are you using high-level inputs?


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## Aqua

Yes that’s right. I use the OEM Composition Color HU with the high level inputs to the DSP. I don’t know but I think that the head unit behaves strange as well. I have checked the output signals from the HU several times just to be sure that I have a clean signal in to the DSP and sometimes I get distortion at 3/4 of the volume and sometimes I don’t get any distortion at all even that I have max volume. I often use my iPhone as an sound source so I have also used that one with Bluetooth connection when I have tried to set the gain level. When I have tried to use the iPhone I have put that volume at max and then measured the output signals from the HU. From the beginning I had a clear signal at full volume both on the phone and the HU but the last attempt I had to reduce the volume with 50% on both to get a clean signal. I believe I should have a professional oscilloscope that maybe works better.

I think that I have made at least 4-5 attempts to get everything right but every time I get different results of the signals.


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## WinWiz

I don't know the hu in your polo but some oem headunits makes "funny" things like speed dependent bass cutting and limited frequencies on some (or all) speaker outputs.


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## Aqua

Yeah. I have noticed that on the rear output from the HU. Much lower volume on both channels.


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## jtrosky

Aqua said:


> Thanks for replaying.
> 
> The system contains of.
> 1. HU: OEM stereo VW Polo 2016
> 2. DSP: Helix DSP.3
> 3. Amp for front: Nakamichi NGXA 120.4
> 4. 6.5” Mids: Rainbow Germanium GL-W6
> 5. Tweeters: Rainbow Germanium GL-T6
> 6. Amp for rear: Ground Zero GZTA 2255X-B
> 7. Rear speakers: Ground Zero GZRF 6.5SQ
> 8. Amp for SUB: Nakamichi NGXD 1600.1
> 9. Sub: Rainbow Germanium GL-S12
> 
> Crossover points.
> Tweeters: HPF 3000Hz, LPF 20.000Hz with a 24db LR filter
> 
> Mids: HPF 80Hz, LPF 3000Hz with a 24db LR filter
> 
> Rear 6.5”: HPF 300Hz, LPF 3000hz with a 24db LR filter.
> 
> Sub: HPF 25Hz, LPF 80Hz with a 24db LR filter.


A few quick things:

1. You want to disable the lowpass filter completely on the tweeters. A 24dB LR low-pass filter at 20khz is not the same as being disabled.

2. Make sure that REW RTA is set to "RTA 1/48 octave". You do NOT want it to be set to "Spectrum" (this is a common mistake since "Spectrum" is the default"). Spectrum mode will screw up your measurements.

3. What is your source for pink noise?

4. Can you adjust your measurement graphs so that the left axis is at 5dB intervals? That is typically what people use on the forum when posting measurements. Yours are in 20db increments. Also - as stated earlier, 20hz - 20khz is more common for the frequency range.

These items will help others help you.


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## Aqua

Thanks for those suggestions. I will of course try to change those settings in REW. 👍


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## HotHatch

** DELETE **

Figured it out


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