Cannot disable Builtin Mic

[AllenV]

I am streaming broadcasts originating from OBS via Zoom using OBS's "Virtual Camera".  

The problem I am having is that no matter what I do, and no matter what "Microphone" source I select within Zoom's Audio Settings, my MacBook Pro's builtin laptop microphone remains enabled.  This is causing HUGE problems with echo and feedback.  

Note: OBS is not the problem - I can shut down OBS, set Zoom's "Microphone input" to any other audio source, and Zoom will still be picking up audio from the builtin Microphone.

[AllenV]

I should note that this is a 2019 MacBook Pro, running the latest OS (MacOS Monterey v. 12.1)

[AllenV · Accepted solution]

Just discovered the problem: I have a Logitech StreamCam connected to the laptop.  Apparently, the "Logi Capture" companion app was the source of the problem.  It was the camera's microphone that was enabled regardless of system and zoom settings.  Disconnecting this camera solved the problem.