What a lifesaver. Seriously, thank you so much. My issue was that if I chose ishowu as the output in my mac settings sound would no longer come out of my headphones. Using the audio MIDI setup and making a multi-output device fixed that. So again, many thanks.
When I set the OBS inputs to my main output and ishowu, my audio quality degrades significantly and at one point went into slow motion, not sure what's going on... The Multi-output device also kept defaulting at 16khz but even after I uninstalled ishowu and deleted the M/O device, OBS kept degrading my audio quality. I only regained HD audio after removing the new obs input devices / closing obs