These mics seem to be nothing special but they are made to work with the sound 'chirps' that contain certain frequencies. I have a Yamaha RX-V773 and the CX-A5000 and they use the same model mic. I think the YPAO versions are a bit different for each one. I should try using the mic from my 4520 on one of the Yamaha's and see what difference it ... More @Wikipedia
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