# Could REQW calibrate a mic?



## Peter De Smidt (Dec 22, 2006)

Could REQW be modified to calibrate our mics? What I have in mind is the following: a measurement sweep could be made. Then a wideband filter could be activated on the BFD that covers the entire sub range, and another sweep run. At this point REQW could compare the predicted results of the filter to the actual results and make a calibration file based on the differences. Does this make any sense?


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## JohnM (Apr 11, 2006)

Unfortunately not in that way 

To calibrate you need some absolute reference, making measurements with and without filters won't help if you use the same mic for both, the change in the measurement due to the filter will be the same whatever mic you use, but both measurements would still be only as accurate as the actual mic response. The main routes are to either have a calibrated reference source that is coupled directly to the end of the mic, so that any deviation from flat is due to the mic, or to make a measurement with a mic that has ben calibrated against a reference source then compare that with a measurement of the mic to be calibrated, and use the difference to create the cal file. This could be made easier in REW by providing an option to show/save the difference between two measurements, which is on my list of features to add.


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