Re: Calibrating measurement mics.-Freq response
One of the problems with a calibrator is that all it does is give you a reference at 1 or 2 freq.
It does not show you the freq response of the mic or any way to check that.
I us multi mics in my alignment setup. I origionally used the origional Superlux 999 mics (before the quality dropped) and they held up real well over a couple of years.
I would always do my own ''calibration'' before each measurement session. I knew which one had the lowest output and would turn on a single loudspeaker and capture that trace. Then I would swap out mics in the same position and adjust the levels as needed so the matched the reference.
This also would give me a chance to keep tabs on the freq response.
Two of the mics started to ''drift'', so I got some real measurement mics. They are ''dead nuts on'' in response and level.
The claibrator assumes the response of the mic is totally flat. If it is not, then the measured SPL could be off.
I had a link (but have lost it) to a guy who measured something like50 of the Behringer mics. And overlaid them. There was quite a variance in level and response. If you don't know exactly where your mic is on the response curve-you could easily make the wrong decision.
Of course having a measured response curve of the particular mic (like you would get from rational) is a great start.
