HOWTO: Stop bluetooth headsets/devices from changing default audio input in Big Sur

This isn't really hackintosh specific but, Basically I now use a bluetooth speaker for my setup, but every damn time I fiddled with the audio settings or even just out of the blue, the default microphone input would switch from internal built-in back to my bluetooth speakers mic and would cause issues forcing it on HFP and giving me terrible audio quality.

This can also be used to force any input/output as default on macOS.

All you gotta do is:

1. open Audio MIDI Setup (you can spotlight search it)
2. press the + on the bottom left, select "Create Aggregate Device"
3. Now name it whatever ya want, and click a checkmark on the audio input (or output) you want as default. Right click your new aggregate device and click "use this device for sound input (or output)"
4. Done, now it should stay as that input even after a restart or reconnection of a bluetooth headset.

Audio MIDI Settings

*Sigh* you would think there would be a way to outright disable inputs/outputs altogether in macOS like in windows.