Hi Jeremy,
Thanks for the reply. YES, I have used Loopback and other apps to wire the output of Logic (and other audio apps) and create a virtual input source to FaceTime. The problem appears to be that FaceTime only listens for input on channel 1. This means I have to convert my stereo sound in Logic Pro to MONO (and that truly sucks).
Also, using Loopback, the sound, once a FaceTime call is engaged, degrades both in quality and in volume. So, it hasn't be a solution.
I think the solution has to be done by the FaceTime team: we need to be able to sum any input sources coming out of different apps on the system (wish we could this on iPad Pro as well as a Mac) and use that virtual, summed STEREO input source as the source input for FaceTime. Then coming back out of FaceTime (to hear the person or persons on the other end, if doing a multi-chat conference), we can route that output, IN STEREO, to any number of output sources on the system. We also need to keep the audio from being compressed and EQ'd for voice. The audio quality has to be intact coming out of Logic, as an example.
Further, we should be able to RECORD the entire session, as you can with ZOOM - that is, the video + audio FaceTime session.
In this day and age, and in particular given COVID and the future of online music, education and collaboration, I would think Apple would want provide these features to FaceTime. I hope they don't miss the boat on this one. FT has the best quality, but it's lacking in critical features at this juncture.