We are aware that there is a limitation with OBS on Mac which means all inputs on the interface (including loopback) are summed together. The method below details a workaround using third-party software so that computer audio can be separated from the physical inputs on your audio interface.

Setting up OBS to receive computer audio

Install BlackHole 2ch and select it as your Mac's audio output device.

Open OBS > Settings > Audio > Global Audio Devices and select BlackHole 2ch under Desktop Audio. Click Apply and then OK.

Setting up OBS to receive inputs from your audio interface

Click the + icon in the Sources section and select Audio Input Capture.

Name your Audio Input Capture and click OK.

Set the Device to your interface and click OK.

Monitoring your audio

Navigate to OBS' Advanced Audio Properties within the Audio Mixer section. Each source has an Audio Monitoring setting, set this as appropriate (i.e. Monitor and Output).