AFMG Network Forum

Eric · Member

Some companies, like Audix sell their measurement mics in matched pairs. How important is it to have matched mics when doing multi channel measurements?
I think it's a given that the mics should be the same but does factory matching matter?

Bruce · Member

Hi Eric,

There are two primary issues used to select Matched Pairs of microphones.
1) Sensitivity
2) Frequency Response

Both of these are critical for coincident microphone techniques in stereo recording, that is, the closer they are matched for both, the better the stereo imaging in the recording.

Have a look here for the way Microtech-Gefell matches microphones: http://www.gefell-mics.com/testing_and_matching.htm

For measurement purposes, these items are less important. Sensitivity can be completely accounted for in the calibration of each microphone, for instance, so even having widely different sensitivities is not an issue. Frequency Response is a bit more important in that any response aberations will then be translated to the Spectrum and Frequency Transfer Function displays.

In EASERA, this can be completely compensated by using reference files for each microphone. This capability is not yet available in SysTune. This really becomes an issue of cost versus how close you feel you need to match the response. The real question is how closely matched might two $250 microphones be. I was not able to find any specifications for this from the Audix site.

Ron Sauro · Member

Eric..... sorry I have not been on the forum very much for numerous reasons..... We use 19 matched sets of M-30 Mics from Earthworks.... We have found that it helps us with our measurements of speakers but for room acoustics I am not sure it is absolutely necessary
Ron Sauro
NWAA Labs

Eric · Member

Hi Ron,
Thanks for the reply. I won't be using them to measure speakers, just rooms and spl. From what you and Bruce have told me, I'm not going to worry about getting a matched pair right now.
Thanks both of you for the info!