Capture audio on Mac OS by OBS
1. download blackhole 2ch version from https://existential.audio/blackhole / and install 2. open audio MIDI Setup.app and clikc left down + sign to add new Multi Output Device Select MacBook Pro both Speaker and BlackHole 2ch 3. move cursor to Multi Output Device and right click mouse to set it to be the default speaker 4. download OBS app from https://obsproject.com/download and install it 5. execute OBS App and and choose Audio Output Capture 6. Choose Device is BlackHole 2ch and click OK, and then Audio Mixer will have fluctuant channel bars as follow figures 7. Click Start Recording and the video file will be stored in ~/movie folder by default. refereces https://streamlabs.com/content-hub/post/capturing-desktop-audio-in-streamlabs-obs-for-mac