[jlohl]

REW won't operate with a USB mic

I have used this one successfully with B&K4006, KlarkTeknik measurement mics, ecm8000 and various softs (REW, R+D, ARTA,...) :
http://www.mxlmics.com/products/USB/MicMate_Classic/MicMate_Classic.html
I also checked its frequency response which was OK for acoustic measurements (+-0.5dB 30 to 15kHz, if I remember)

 

[jlohl]

So you DID get this to work well with REW?

yes, Micmate works fine with REW

on a USB mic the frequency response should be in the spec

the Micmate and equivalent products are not usb mics : it's just an external soundboard with phantom power supply. Before using the Micmate, I measured the frequency response for my calibration : it was good enough for acoustic measurements. So the measurement quality depends only on the mic you use.

 

[jlohl]

How are you able to do a soundcard calibration when using USB as the input?

I connected a measurement generator (Audio Precision, Prism or equivalent) on the input of the mixmate and recorded a wav file. Then I analysed this file (frequency response, distortion). This response added to the cal file of the mic itself gives me the global cal file to use.