Using Yamaha receiver calibration microphone for speaker testing?

[camshaft]

Hey guys,
My Yamaha home theater receiver has that feature where it comes with a small microphone that you put on your coffee table and the receiver uses it to calibrate the speaker settings. I was going to do the diy panasonic microphone module attempt to make a speaker testing microphone, but then I wondered whether the yamaha mic would be accurate enough to produce any meaningfull results.

Thanks for any help!
Austin