Hi,

the coordinates in mic_geometry are relative to the _center_ of the bounding box of the mic array, this is quite clear in the comments in the code (see echo-cancel/webrtc.cc::parse_mic_geometry()), but the word "center" is not present in the wiki documentation, and the first time I read the parameter description it was not immediately clear to me how to specify the coordinates:

https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Modules/?updated#index45h3

Maybe the description can be changed like this:

...the first three numbers specify the coordinates of the first [-mic,-] {+mic relative to the "center" of the microphone array,+} and the last ...

Thanks,
   Antonio