# Binaural Mics used for REW? am i making a mistake?



## Guest (Dec 2, 2008)

Hey all,

I just started with REW, and so far so good! I'm using a portable mic setup I used for ambient field recordings: sound-professional in-ear binaural mics that I run thru a core audio portable a/d converter (Core Sound Mic2496) to run into my mac and am able to get room readings, etc.

Do you think this will be alright to use for calibrate the system, or should i step up and buy a regular mic? 

thanks in advance, rams


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## brucek (Apr 11, 2006)

REW accepts a mono line-in signal. The binaural mic outputs a stereo signal on a stereo plug, so you would only receive one of the channels into REW. You would also require a calibration file in REW.

brucek


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## Guest (Dec 4, 2008)

Okay, thanks brucek. I've been able to get readings so far without too much difficulty with the binaural mics.


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## tonyvdb (Sep 5, 2007)

overmedium said:


> Okay, thanks brucek. I've been able to get readings so far without too much difficulty with the binaural mics.


Without the proper calibration file for that particular mic you will not get accurate readings and thus rendering your final graph useless. Right now the only calibration files we have available is for the Galaxy CM140 SPL, Radio Shack SPL, and the ECM8000 mic. Available here 
A calibration file can be made but you would require the detailed specifications of the mic your using including frequency response.


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## Guest (Dec 4, 2008)

tonyvdb:

thanks for clearing that up. Did i miss this rather crucial detail when i read the tutorial guide (getting started with REW, calibrating soundcard, check levels, etc)? :scratch:

-rams


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## brucek (Apr 11, 2006)

Yes, I mentioned it above in my post: _You would also require a calibration file in REW.
_
It's also included in the REW Help Files.

A microphones response is never flat at its extremes, and so requires a file to render it flat. Without a calibration file, the measurement is usually quite inaccurate at the low end.

brucek


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## Guest (Dec 4, 2008)

brucek said:


> Yes, I mentioned it above in my post: _You would also require a calibration file in REW.
> _



Yes, I see that you mentioned that, that's what prompted my inquiry of that information in the REW help file.

p.s. I couldn't find this information in the REW help file in regards to the 3 calibration files you mentioned. Sorry I'm being dumb (I'm just recovering the from flu.....:dizzy


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## brucek (Apr 11, 2006)

> 3 calibration files you mentioned


Three?

A microphone or SPL meter requires a single calibration file. The file is loaded into REW to render the microphone or SPL meter flat.

We have generic calibration files for a few types of SPL meters and also for a Behringer ECM8000 microphone available on our download page.

If you use an SPL meter of microphone that is different than the one we have files for, you will have to supply your own file through an independant calibration, or created from a set of specifications.

brucek


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## Guest (Dec 4, 2008)

Yes, you mentioned three in your earlier post: "Right now the only calibration files we have available is for the Galaxy CM140 SPL, Radio Shack SPL, and the ECM8000 mic."

This independant calibration you mentioned, is this something that I can do myself? Again sorry for my thick-headedness.....


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## brucek (Apr 11, 2006)

> This independant calibration you mentioned, is this something that I can do myself?


No, you send the mic to a certified calibrator such as West Caldwell and they create the file for you.
It's cheaper to simply purchase a good SPL meter such as the Galaxy CM-140 and use the generic file on our site.

brucek


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## Guest (Dec 9, 2008)

okay, thanks for clearing that up. I knew I shouldn't have been even thinking about REW when I was sick, but I was really bored and could muster just enough energy to type a reply but that proved to be not the wisest choice.


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