The microphone button controls the built-in microphones which are used for the active room compensation performed during setup.
If you press and hold the microphone icon, the microphones are muted, and the microphone icon will turn red.
You can disable the microphones permanently by toggling the microphone switch in the socket panel to the off position. The microphone icon on the top panel will turn off.
Please note that room calibration cannot be completed if the microphones are muted or disabled.
