# Soundcard calibration questions



## bluemax_1 (Feb 14, 2011)

Trying to figure out what I'm doing wrong with my soundcard calibration?

I guess my main confusion is with the Input/Output Device settings.

I'm using a Roland Quad Capture external USB soundcard on my Sager laptop running REW v5 on Windows 7 Ultimate 64-bit.

These are the settings I used:

Output Device and Output:
1-2 (QUAD-CAPTURE)
LINE_OUT

Input Device and Input:
MAIN (QUAD-CAPTURE)
LINE_IN (Master Volume)

Wave Volume: 1.000
Output Volume: 1.000
Sweep Volume: -12.0 db FS

Input Volume: 1.000
Input Channel: Right

Connected a 1/4" TRS-TRS balanced cable for the loopback from the Right output to the Right Input on the QuadCapture.

With headphones connected to the QuadC, I can hear the test tones and sweep. This was the result though:


So what am I doing wrong? My Frequency Response graph looks nothing like all the other graphs I've seen posted by other folks when I searched for "soundcard calibration"



Thanks,
Max


----------



## eastman17c (Sep 15, 2011)

Im also new in this forum, I am also using laptop with windows 7 , check your connection and windows setting, there is a thread here that explain using win7 just search it. I have posted my soundcard response above see it , Im using USB BeHringer UCA202 and built in card from Dell.


----------



## bluemax_1 (Feb 14, 2011)

Are you talking about this thread?
http://www.hometheatershack.com/for...solutions-calibration-rew-windows-7-more.html

If so, I did read that thread while setting up REW, but I'm wondering about the Input and Output Device settings. That thread also happens to be an older version of REW.

Under the '*Output Device and Output*' selections,
my options are:
*Default Device
Primary Sound Driver
1-2 (QUAD-CAPTURE)
3-4 (QUAD CAPTURE)
Realtek Digital Output (Realtek High Definition Audio)
Speakers (Realtek High Definition Audio)
Java Sound Audio Engine*

If I select anything other than one of the Quad Capture options, the '*Output*' tab below is greyed out and *'Default Output*' is the only option. If I select one of the Quad Capture options, then in the '*Output*' tab, I can choose between '*Default Output*' and *'LINE_OUT*', so I picked '*1-2 (QUAD-CAPTURE)*' and '*LINE_OUT*'.

Under '*Input Device and Input*'
my options are:
*Default Device
Primary Sound Capture Driver
1-2 (QUAD-CAPTURE)
Microphone (Realtek High Definition Audio)
MAIN (QUAD-CAPTURE)
3-4 (QUAD-CAPTURE)*

If I select anything other than '*MAIN (QUAD-CAPTURE)*' in the Device List, the '*Input*' option box defaults to *'Default Input*' and is greyed out. If I select '*MAIN (QUAD-CAPTURE)*' in the Device List, then under '*Input*', I can either select '*Default Input*' or '*LINE_IN (Master Volume)*', so I selected '*MAIN (QUAD-CAPTURE)*' and '*LINE_IN (Master Volume)*'.

Should I be selecting something else in the list of available choices? As I mentioned, when I hooked up everything and set it up this way, I can hear the test tones and sweeps through my headphones which are plugged directly into the Roland Quad Capture. I can see, and adjust the levels on the 'In' and 'Ref In' meters when I hit the 'Check Levels' button and when I run the soundcard calibration etc.

Setting the 'Input Volume' to 1.000 resulted in the 'In' levels at -12.0 db. I later set the 'Input Volume' to 0.501 to get an 'In' level of about -18.0 db as the Help guide suggested -18.0db as an ideal target and levels over -12.0 db might result in clipping.


Max


----------



## bluemax_1 (Feb 14, 2011)

Did more investigating/experimenting and found some interesting oddities.

In Windows 7, I set the Playback default device to 
1-2 QUAD-CAPTURE
Level to 97

Recording Default Device to
MAIN QUAD-CAPTURE
Under the 'Advanced' tab, I set it to allow applications to control the device and changing the Input levels in REW v5 result in direct changes to the level settings here (set at 50 for now).

Setting these to anything else don't produce usable results (although I CAN set the 'Recording' device to 'Microphone Realtek High Definition Audio', which, as it turns out, uses the built-in microphone in the laptop).

Anyway, with the above settings in Windows 7, I discovered that I could produce a range of interestingly weird graphs by adjusting one little knob on the Roland Quad Capture.

I don't have the 5 posts yet to post external links about the Quad Capture, but it has a couple of knobs on the front right for monitoring purposes. The output knob controls the volume out of the headphone out AND the rear 1/4" outputs simultaneously. There is also a 'Mix' knob that allows the user to control the mix between whatever is being fed into the inputs and whatever is being played out of the outputs.

Fully counterclockwise, the only thing coming out of the outputs (and headphones) is whatever is being played back on the system the QuadC is hooked up to. Fully clockwise, the only thing coming out of the headphones and outputs will be whatever is being fed into the recording inputs.

Without changing anything else aside from turning that knob, I managed to generate increasingly odd graphs.

The first graph (that shows a flatline) is with the Mix knob set fully counterclockwise to Playback only. The Impulse graph looks like the first Impulse graph I posted.

The subsequent graphs were generated after turning the knob clockwise by increments which means the Outputs are mixing in progressively more of the Input.



Max


----------



## bluemax_1 (Feb 14, 2011)

Is it possible for a soundcard/audio interface to generate a calibration that is a completely flat line from <2Hz to 22.1kHz+? 

This is what REW says in the window next to the graphs:
Sample rate: 44100 Hz
-3 dB points: <2.0 Hz, 22.050 kHz
Input device: MAIN (QUAD-CAPTURE)
Input: LINE_IN (Master Volume)
Channel: Right
Input volume: 0.500
Input RMS target: -12.0 dB
Actual RMS at 1 kHz: -18.5 dB
Output device: 1-2 (QUAD-CAPTURE)
Output: LINE_OUT
Sweep level: -12.0 dB
20 Hz .. 20 kHz flatness: +0.0, -0.0 dB


Max


----------



## EarlK (Jan 1, 2010)

Hi BlueMax,

You're in good shape, so don't fixate about that flat line ( just because 99% of us don't get that / consider this, I've never seen anyone at this site mention using your particular card ) .

I'll agree that getting a perfectly flatline from 2hz to 22Khz is very rare / but that's a good thing ( & speaks well of Roland ) .

I read through all the iterations that you just tried and the one that gives you the flatline is the correct one . :T

You've discovered what the "mix" does ( which is great to see :clap: ) and how it messes with the trace when you add the REW signal back into itself :rolleyesno: ( that's called circuit "feedback" in my world ) . 
- Obviously keep that knob set to monitor just the signal coming from the computer ( ie; knob turned fully counter-clockwise ) .

Make a SC calibration ( name it & save it ) and move on to other areas of REW ( like calibrating the SPL meter ) and then perform a sweep of a speaker.

<> :sn:


----------



## bluemax_1 (Feb 14, 2011)

EarlK said:


> Hi BlueMax,
> 
> You're in good shape, so don't fixate about that flat line ( just because 99% of us don't get that / consider this, I've never seen anyone at this site mention using your particular card ) .
> 
> ...


Thanks for the heads up. Yes, the card is regarded fairly well for high fidelity mobile recording. It's good to confirm that they did a pretty good job with it.

Next question, I have a calibrated EMM-6 microphone (Premium+ from Cross Spectrum Labs) to use with REW, do I still need to hook up an SPL meter or do I simply use that to ensure that the adjusted SPL's that REW is displaying during measurements are similar to what is measured at the measurement positions with the SPL meter?

How do I enter the calibration file for the EMM-6 into REW?


Thanks again for the assistance.
Max


----------



## EarlK (Jan 1, 2010)

> How do I enter the calibration file for the EMM-6 into REW?



You load your microphone .cal file from within REWs' preferences window / under the pull-down tab called "Mic/Meter" .

:sn:


----------



## bluemax_1 (Feb 14, 2011)

EarlK said:


> You load your microphone .cal file from within REWs' preferences window / under the pull-down tab called "Mic/Meter" .
> 
> :sn:


Excellent! Off to measure now. Thanks!


Max


----------



## aackthpt (Jan 24, 2011)

bluemax_1 said:


> Next question, I have a calibrated EMM-6 microphone (Premium+ from Cross Spectrum Labs) to use with REW, do I still need to hook up an SPL meter or do I simply use that to ensure that the adjusted SPL's that REW is displaying during measurements are similar to what is measured at the measurement positions with the SPL meter?


REW's online help has pages titled the following, which is generally the order one goes in setting up:
Calibrating the Soundcard
Checking Levels
Calibrating the SPL Reading
Making Measurements 

You have completed the first two, so generally you would want to go in order, though it is possible to skip straight to the fourth. It doesn't matter much, but if you do the "calibrating the SPL reading" step each time you change the gain on the input chain, then the SPL meter within REW will read the same, and your graphs will represent actual levels. The reason this is not very important as we are after relative measurements e.g. "how flat is the response" or "did adding an acoustical treatment do anything". In my case I got lucky, and have an easy way to know that my input gain is consistent (the input level knob is all the way up) so I only very rarely redo the SPL reading calibration step - generally only as a double check that things are working properly.


----------



## bluemax_1 (Feb 14, 2011)

More weirdness.

Using the settings in my 1st post:

Output Device and Output:
1-2 (QUAD-CAPTURE)
LINE_OUT

Input Device and Input:
MAIN (QUAD-CAPTURE)
LINE_IN (Master Volume)

The calibration seems to run fine, but then I discovered that when I disconnected the loopback cable, I could hit the 'Check Level' button and still see the 'In' and 'Ref In' levels rising with the 'Out' signal.

As it turns out, with the Input Device setting on 'MAIN (QUAD-CAPTURE) and the Input setting on 'LINE_IN (Master Volume)', I cannot get any Input when I hook up the microphone to the Quad Capture. I need to use '1-2 (QUAD-CAPTURE)' for the Input Device, which also means that the Input is automatically set to 'Default Input'. 

The problem is, with the Device Input setting at '1-2 (QUAD-CAPTURE)' and Input at 'Default Input', the In levels are really low, even if I set the Input Volume at 1.000 and crank up the Quad Capture's input volume knob all the way (which registers a clipping signal on the QuadC's VU meter).

It's not the Quad Capture as I can see the Input levels with the VU meter on the front and they rise with increased SPL's.

Any suggestions?


Max


----------



## EarlK (Jan 1, 2010)

> Any suggestions?


Turn up your outputs ( either on the sound card ) or at your AVR .

Then you can back-off your soundcards inputs by an appropriate amount.

:sn:

PS; ( PICs are our friends here :whistling: ) . 
> ie; A Screen Capture of REWs' open Preferences Window ( captured during a sweep ) is useful for the rest of us to see ( & even though you've described them, try to show your "IO Device" & "Soft-Patch" settings ) .


----------



## bluemax_1 (Feb 14, 2011)

EarlK said:


> Turn up your outputs ( either on the sound card ) or at your AVR .
> 
> Then you can back-off your soundcards inputs by an appropriate amount.
> 
> ...


I tried turning up the levels on all the equipment, with the Output Volume in REW set at 1.000, the level volume in Win7 set at 100, and the avr turned up to -15db Relative. At these setttings, the Check Level rumble is substantial and I can see the VU meter on the Quad Capture showing good recording/Input levels from the microphone, but for some reason, the 'In' levels in REW are still really low.

BTW, how do I take a screen capture of the Preferences Window? I see the 'capture' button for the graphs in the measurement window.


Max


----------



## JohnM (Apr 11, 2006)

To get a result which is that flat means there is a direct digital data path from output to input. As your loopback is an analog cable that suggests there is an internal loopback active. You are probably best off using the latest REW Beta and ASIO drivers for your soundcard, then look at soundcard setup from there.


----------



## EarlK (Jan 1, 2010)

Max said:


> BTW, how do I take a screen capture of the Preferences Window? I see the 'capture' button for the graphs in the measurement window.


> You'll need to use Windows builtin Screen Capture method ( in my laptop ; press Fn then F11 > then paste the capture into "Paint" then resize in paint to something reasonable > then save as a jpeg or paint file for upload ) .



JohnM said:


> To get a result which is that flat means there is a direct digital data path from output to input. As your loopback is an analog cable that suggests there is an internal loopback active. You are probably best off using the latest REW Beta and ASIO drivers for your soundcard, then look at soundcard setup from there.


Johns right ( and as you've discovered ) ( & as I just read within the QuadCaptures User Manual ) , your soundcard provides a digital loopback originating from its' software based "Direct" mixer ( Rolands own DSP based audio control panel ) . It looks like those digital channels will be labelled 5-6 ( if you go looking for them ).

> You were likely seeing REWs output looped-back ( softpatched ) directly into the input ( even after removing the physical cables ) because 5 & 6 showed up at that wave based "Master Volume" ( & they weren't muted ) . 
> That's my working theory for now, sorry for initially giving you a False Positive "Green-Light" to proceed .



> At these setttings, the Check Level rumble is substantial and I can see the VU meter on the Quad Capture showing good recording/Input levels from the microphone, but for some reason, the 'In' levels in REW are still really low


> Try selecting the left input within REW ( as well as using it on the Quad Capture ) . 
> Win7 ships defaulted to only record in mono through the left channel .
> If your levels substantially increase then it means you haven't set your windows audio control panel to input in stereo . 










> You'll need to explore Win7(s) audio control panel ( seen above ) & then rectify the situation (ie; turn on 2-chnl recording ) .


:sn:

PS : This soundcard has a few different ways you can mess with a pure signal ( found within "Direct Mixer" ) . 
You'll want to familiarize yourself with that mixers dsp functions before it trips you up.


----------



## bluemax_1 (Feb 14, 2011)

Thanks John, and Wow Earl, good info. Yeah, I'll have to look into the card a little more.

Yes, I HAVE changed the Windows settings to 2-channel 16-bit 44.1kHz, and I tried using 5.0.1 Beta with the ASIO drivers and was still having problems. I'm out of town till Tuesday, but when I get back, I'll look into the card's DSP channels to figure out where my problem lies.

Recording audio with the card and a Mic was evidently a lot easier to set up than calibrating with REW.


Max


----------



## Jibara (Nov 30, 2011)

Boy this seems daunting but it is good to see such a forum community to learn from.


----------



## bluemax_1 (Feb 14, 2011)

Thanks for all your patience everyone. Well I finally got back in town and had some time to check everything again and I *think* I've found the problem.

For anyone interested, it was a Windows 7 setting I had to go into the 'Sound' settings in the 'Control Panel' and under 'Recording', I had unchecked the 'Listen To This Device' box under '1-2 (QUAD-CAPTURE)' but it appears I didn't do this under 'MAIN (QUAD-CAPTURE)'.

This in turn caused feedback in some configurations of the card, thus I couldn't use them without producing some seriously funky graphs.

Here's what the new calibration graph looks like. Finally, something that looks normal:
Now to actually try measuring with the card


Max


----------



## bluemax_1 (Feb 14, 2011)

Well here are the results

1) is with the Boston Acoustic E100 (right main) + 2 Bag End Infrasub-18's No EQ applied
2) is the above with Audyssey MultEQ XT32


Max

P.S. the No EQ measurement clipped right at the beginning which I believe is why it shows FR down low


----------



## bluemax_1 (Feb 14, 2011)

BTW, I'm running the speakers with a 40Hz crossover.


Max


----------



## cocoflunchy (Mar 9, 2012)

Hey there, it's my first post on HTShack :wave:

I'm trying to use REW to measure the acoustic response of my room, and it turns out I have a Roland Quad-Capture like bluemax. 
That's why I'm also posting here rather than creating a new thread, hope that's OK.

So I'm having exactly the same flat response problem that bluemax had in the beginning except that my 'Listen To This Device' box is already unchecked and there's still this loopback problem. I've also tried to use the asio drivers but it doesn't seem to work (I can't choose my Quad-Capture as an output device).

I'm a little lost, because otherwise the sound card works perfectly both for playback and recording...

Here's a screenshot of my configuration : http://imageshack.us/f/850/82066028.jpg/

If I choose 'Quad-Capture 1-2' for the output, no sound is produced.
If I choose 'Quad-Capture 1-2' for the intput, no sound is detected.
If I choose 'Quad-Capture MAIN' for the intput, there's a digital loopback.

If anyone has an idea, please share !


----------



## aackthpt (Jan 24, 2011)

cocoflunchy, welcome to The Shack.

The problem is not in REW, the problem is either in your Windows configuration or in your configuration of the soundcard driver. I suggest you read and understand the earlier portions of the thread carefully to see if you can figure it out, and if not then post Windows and sound card configuration screen captures.


----------



## cocoflunchy (Mar 9, 2012)

OK so... turns out I had simply forgotten to activate the phantom alim. :R

Now everything works just fine !


----------



## aackthpt (Jan 24, 2011)

cocoflunchy said:


> OK so... turns out I had simply forgotten to activate the phantom alim. :R
> 
> Now everything works just fine !


A phantom islamic scholar????

No entiendo. :huh:


----------



## cocoflunchy (Mar 9, 2012)

Phantom power :/
Alim is short for 'alimentation' which is french for 'power supply'... sorry about that


----------



## aackthpt (Jan 24, 2011)

Ahh, that makes sense! We use the same word in English for food. It makes sense that that would cross into 'power supply' but my brain was not completing the word efficiently.

But to tell you the truth I was just joking around anyway, since I guessed you meant phantom power. :whistling:


----------



## cocoflunchy (Mar 9, 2012)

Yes, it means food in french too


----------



## rb5K2i (Nov 21, 2015)

bluemax_1 said:


> Are you talking about this thread?
> http://www.hometheatershack.com/for...solutions-calibration-rew-windows-7-more.html
> 
> If so, I did read that thread while setting up REW, but I'm wondering about the Input and Output Device settings. That thread also happens to be an older version of REW.
> ...


i know this is an old thread but i have the same sound interface card and OS.

to get this interface to play through the speakers(connected to a AVR) i want to test, do i need to connect the outputs on the sound interface to my AVR like AUX inputs? 

otherwise the outputs on this interface don't seem to play the speakers i want to test.


----------

