Framework's Stereo Mics Raise Some Questions

I’m currently checking that all the hardware is working ok on my new 11th Gen (Ubuntu) and 12th Gen (Windows) laptops - but it seems I can’t easily check the individual built-in mics (“dual MEMS”). Both OSs are geared to testing a single (mono) mic; likewise the Windows Voice Recorder app only seems to offer mono record/playback.

My background is in broadcast engineering (BBC, Channel 4 UK) and in the past I’ve come across instances where someone has (allegedly) made a stereo source mono by taking just the left channel (rather than by adding left and right and reducing by 6 - or possibly 3 - dB). That’s the easy way to do it, of course - but it’s not the right way.

Before I install Audacity to investigate further, just wondered if anyone knows/has worked out how the Framework dual mics are treated when using the OS to test the built-in mic or with apps that are mono-only.


Could be possible to test by just tapping the mics, I’m by no means an audio person though!

Yes, I tried that but it was inconclusive. Likewise when I tried covering the bezel apertures with my thumb!

The microphone array is seen as 2 channels in Windows, so the behavior of mono apps would be up to the application. If you record in Audacity, you will get stereo audio, assuming everything is working

Edit: I might have a different audio codec than you do, since I have the original Realtek one

If the mic array is seen as two channels in Windows, I wonder why the mic test feature in Settings/System/Sound is only one channel? Likewise the built-in Voice Recorder app. Would be good to find out what the inputs to these really are - one mic only, or the sum of both?