'Front' and external mic cal interference.

[Ian Eales]

The front mic used to be close enough relative to other meters and calibrated microphone on REW BEFORE I added the imm6 cal. 

When I added the cal file for the imm-6, the front mic cal is all wrong, both level and curve.

I have a microphone calibrator and the imm6 is spot on @ 94 & 114dB 1kHz. The imm6 frequency response measurement corresponds well enough to my main calibrated microphone and laptop using REW.

After adding the imm6 cal, the front mic is about 10dB low and humped with decreased LF & UM/HF

I'm assuming the phone & os came with a reasonable facsimile of a 'calibration' applied before AudioTool sees the data.

How to get AudioTool to either use a null front cal where every frequency is zero or use no cal file?

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AudioTool is a GREAT APP.

Using since about 2018... irrc

Thanks!

[Julian Bunn]

Hi Ian,

I'm not sure I fully understand what is going on here. But, you can certainly create a flat 0dB curve to use as calibration. This is described in the manual here:

https://sites.google.com/site/bofinit/audiotool#h.p_ID_923

where you would use "Calibrate" and just simply leave all the 1/3 octave values at 0dB and save the calibration. You can also defeat the 1/3 octave calibration and use the "single value" method with 0dB.

Julian