# Newbie - Can't get soundcard calibration to run



## cuzed2 (May 18, 2011)

OK - please be nice 
I'm an obvious newbie and can't even get to the starting gate (And I did read REW V5 Help - at least up thru "Calibrating the Soundcard"

My set up:
Dell E6400 Latitude laptop (Intel core 2, w/3Gb ram, WIN7)
UCA202 USB interface to my laptop
Xenyx 502 preamp w/Dayton EMM6

I suspect my problem is with getting my laptop sound card to communicate with REW.
Under REW preferences - I am using the default setting for Soundcard settings (input and output)
I have the right channel input and outputs of the UCA202 looped together (and the UCA power light is indeed on).

When I hit the REW cal button - everything greys out and nothing seems to happen

Tried to find my soundcard controls within the Dell - but all I could find under device manager is what appears to be a choice of drivers (and the list below does not match the choices shown in REW soundcard preferences)

Under the Dell Device Manger for Sound, Video , and Game Controllers:
-IDT Hi-definition Audio Codec
-Intel Hi-definition Audio Codec
-USB audio codec

I am sure I am missing something very simple, perhaps as simple as finding and identifying the soundcard controls in my Dell...???

Thanks In Advance!
CuzEd2


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## cuzed2 (May 18, 2011)

One Step Forward?

OK I revisited the control panel on my Dell laptop. It looks like the 202 is recognized as a generic USB audio device. So I then went to the REW preferences tab and:

Set the output device to USB Audio Codec
then I had a choice of Default output or Speaker >> chose default output

Set the Input Device to USB Audio Codec
and selected the default input 

Clicked on the Calibrate button and minimized this preferences page.

From the main REW page, I clicked on Measure, and got a pop-up saying "SPL meter has not been calibrated"

I clicked continue anyway
then clicked Start Measuring 

Looks like the magic is starting to happen, as I got a graph with 3 lines.
- a blue flat line
-bright red Phase line which was linear with slight rise to the right
-and a darker Red line with an even steeper and linear drop off to the right

I'll share a screen shot later, I assume this newbie might now be on the right track?

Thanks ...


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## JohnM (Apr 11, 2006)

Sounds promising, the screen shot will show for sure.


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## cuzed2 (May 18, 2011)

Thanks JohnM!

OK so I ran two more soundcard cal's:

*Setting 1. * The one immediately below is the result when I selected the more generic, USB option from the REW preferences for input/output choices. I would like to believe that this is a good sound-card cal??










*Setting 2:* And the one below is from the REW preferences selection when selecting "default"; for input a nd output options. I have to wonder if this is just noise or oscillations from an open input/output ...??? But then again I am a "newbie" who is guessing 









Any / All help is appreciated - Thanks!!


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## cuzed2 (May 18, 2011)

Any comments on these sound card cal attempts?

Thanks!
Cuzed2


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## JohnM (Apr 11, 2006)

The second attempt is, as you suspected, the result of an unconnected input. If you tell REW to use "default" then you have to make sure the device and input input you actually want to use are selected as the defaults in the Windows sound controls. The first measurement looks better, but it is very difficult to tell as the images are too small to see - there is an odd slope to the measurement. To save an image of the graph use the Capture button (the camera icon) and before you do that make sure the frequency range of the graph goes right out to at least 24kHz (you can set the span using the Limits button or just click the zoom out "-" button that appears when your mouse is over the graph).


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## cuzed2 (May 18, 2011)

JohnM,

Thanks! I have also just searched and found an excellent UCA202 tutorial by "mj79".
I think I am now armed to give it an other try tonight!

Regards,
Cuzed2


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## cuzed2 (May 18, 2011)

JohnM,

First off I need to commend you on this software; even though I am a newbie and floundering about; it is easy to appreciate that this software is very powerful, and very stable - even I can't get it to "hang" 

So using mj79s excellent tutorial;
I gave the UCA202 sound card another set up and cal. attempt last night. I believe I can report some incremental progress, as the setup seemed to go well? Attached are 3 calibration measurement spectrum that I saved. My goal has still not been achieved because I could not generate the shape that others have posted with the UCA202? Looking for comments on what I am missing or doing wrong? 

I am also concerned that my UCA202 may have an issue. I say that because I am using ONLY the Right input and Right output (they are looped together, the left side connections are open). When I hit measure > both left and right VU meters were detecting signal (didn't make a difference if the left OR the right was selected), both VU meters reacted the same. I would have expected only one to respond?

In any event; maybe the following will shed some light on my struggles, any and all help is appreciated - THANKS!

Photos will follow in my very next post


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## cuzed2 (May 18, 2011)

And as promised my 2nd attempt at calibrating the UCA 202, see description and questions, immediately above - Thanks for your input and assists:


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## JohnM (Apr 11, 2006)

Looks pretty odd. If you disconnect the loopback cable do you get the same result? How are the REW soundcard preferences set up now, can you post a screenshot?


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## cuzed2 (May 18, 2011)

I'm glad you also felt those screenshots above were odd. I think I just had an "AH-HA !!" moment.
All of my efforts to this point were done using the right channel I/O connections on the UCA202.


So I moved my loop back cable to the Left channel I/O connections on the UCA202. 
Might you agree that the following graphs; suggest I may have found the problem?

Both graphs were made using the Left channel "physical" connections. The first one is with the REW software toggle "right input" selected:










And same physical connections, but this time with the REW set for left input channel:










Seems I have a a UCA202 with a bad right channel! Although I am still not sure why switching the REW input toggle does not make a difference..? 

Any problem in continuing my REW analysis and EQ project using a one channel only UCA202?


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## JohnM (Apr 11, 2006)

Strange indeed, but those measurements look perfect.


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## cuzed2 (May 18, 2011)

Thanks - I needed that!

Just finished reading the rest of the Help / instructional material - well done - excellent documentation. 
Although; the Thiele and Impedance portions, have pushed my own personal "absorption" limits,


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## cuzed2 (May 18, 2011)

I'm now another $100.00 poorer and about at wits end. I'm sure I'm doing something real stupid here - but my head is getting sore; so I will surrender and ask for help. Background: As you can see above - I had some intermittent luck in calibrating the sound card portion of my original set up (Xenyx502 and the UCA202). However; I convinced myself that the UCA202 had a bad channel and couldn't be trusted. So I ordered a new Tascam US-122MKII.

Today was my 2nd attempt to loop back the Left input to the Left output to verify that all is well, and run a sound-card calibration (also got a similar result on the right channel). After 2 more hours I am convinced that I am completely missing something stupid. Here is the sound card calibrate result I keep getting:









I hope this presents a clue as to what I am doing wrong?

The tascam knobset when using the left input:
-mon/mix knob turned full CCW to "input"
-phones/lineout, full CW to "lineout"
-Sig/OL Left Input, full CW to MIC (going full CCW resulted in no input signal at all on the REW VU meter)

REW preferences settings:
Wave Vol = 1.0
Output Vol = .501
input Vol = .501
sweep = -3db

When adjusting to the 1Khz tone; I was measuring -3.0db out, and -6.5 db in (headroom =6.0db)
Everything went well on each attempt UNTIL the measurement is completed and the graph displays


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## JohnM (Apr 11, 2006)

Mon/Mix needs to be turned all the way to "Computer", otherwise you are feeding some or all of the input signal back to the output. The "Input" knob is a gain control, the mic end is max gain, the line end is min gain. It typically needs to be around the 2pm position for a loopback test as I recall, but you can play with it during the part at the start of the soundcard cal when the 1kHz tone is playing to get a sensible input level.


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## JohnM (Apr 11, 2006)

P.S. Set the frequency axis to log, it is linear in the plot you posted - click the button next to the "Limits" button.


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## cuzed2 (May 18, 2011)

JohnM,

Thanks a bunch for the additional tips / corrections. Your definitions for the Tascam controls helped a lot! (I guess it shows that I'm not a musician, and that is what these products are designed for) 

Attached is the most recent result - I think I am now good with the Tascam verification/calibration, any comments, or add'l suggestions?









I'm heading back to the REW Help instructions in order to verify my next steps. I believe my next task will be to calibrate SPL against my Rat Shack analog meter?


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## JohnM (Apr 11, 2006)

cuzed2 said:


> Attached is the most recent result - I think I am now good with the Tascam verification/calibration, any comments, or add'l suggestions?


Looks exactly as it should 



> I'm heading back to the REW Help instructions in order to verify my next steps. I believe my next task will be to calibrate SPL against my Rat Shack analog meter?


Correct.


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## cuzed2 (May 18, 2011)

Thanks!!

After revisiting the Help-Instructions; My next 3 steps will be:

1) To test the soundcard cal file - looking for a corrected response (better than .5db)

2) Check Levels. If I understand correctly; the goal is to make sure the soundcard/REW controls (utilizing a pink noise cal signal) will push my receiver to output 75db on a ratshack meter in the listening position. The amount of push is adjusted with the REW sweep setting, and if necessary one could also adjust the receiver gain, but perhaps it is best to preset my receiver gain to my reference position (in my case "0"), and hopefully the soundcard settings (the sweep level) will get me to 75db on the Ratshack meter ?

3) SPL calibration. Looks like I set the receiver for reference level (and confirm this ref. measurement on the ratshack meter). Then simply a matter of entering this level in the "SPL reading calibration" box to match REW to the RatShack measured level?


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## JohnM (Apr 11, 2006)

cuzed2 said:


> 1) To test the soundcard cal file - looking for a corrected response (better than .5db)


Yes



> 2) Check Levels. If I understand correctly; the goal is to make sure the soundcard/REW controls (utilizing a pink noise cal signal) will push my receiver to output 75db on a ratshack meter in the listening position. The amount of push is adjusted with the REW sweep setting, and if necessary one could also adjust the receiver gain, but perhaps it is best to preset my receiver gain to my reference position (in my case "0"), and hopefully the soundcard settings (the sweep level) will get me to 75db on the Ratshack meter ?


The ref setting can be very loud with normal input levels, I think it is better to have the receiver set at your normal listening volume, less likely to forget and leave it at ref that way which may be a nasty shock when someone sits down to watch something.



> 3) SPL calibration. Looks like I set the receiver for reference level (and confirm this ref. measurement on the ratshack meter). Then simply a matter of entering this level in the "SPL reading calibration" box to match REW to the RatShack measured level?


Again, I'd go for normal listening volume setting. Before you enter the figure and click OK make sure the input level ion REW's meter (shown on the horizontal bar) is not too low or too high, somewhere between -20 dB FS and -12 dB FS is normally OK. _Edit: if the level is outside that range, adjust the soundcard input volume._


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## HansWursT619 (Jan 29, 2011)

Did you use a loopback from Line Out to Mic or Line Out To Line In?
Because my frequency response drops much earlier, -3d at 17hz. I uses Line Out -> Mic.

Maybe there is a diffrence?


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## EarlK (Jan 1, 2010)

Hi Hans,

Here's a pic showing the differences between a calibration using my line input versus the microphone input ( both generated for my M-Audio Fast Track Ultra ) .











As you can see, there's quite a difference . ( Based on what I'm seeing for you & in this thread ), I'm sure that cuzed2 has used line input for his cailbration .

Don't worry , the calibration/correction file generated by REW takes care of these early LF roll-offs ( that you & I have get from our mic pre-amps ) .

<. EarlK


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## HansWursT619 (Jan 29, 2011)

Thank you, nice pic.

That seems to be the reasoin for the difference.


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