5.1 back speakers not working

Hey Todd, thanks for your reply!

I've gone through those steps extensively. I have also found a strange workaround, that I suspect still isn't actual 5.1:

If I choose 6 channels in the MIDI settings, I can get 5.1 from a quicktime test file that I myself created and rendered out through Davinci Resolve (not Dolby Digital encoded, just 6 discrete channels each going to their own speaker/LFE). It behaves just as expected when playing in Quicktime and VLC in macOS, but nothing else works - all the test files I have from Dolby produce no sound at all from the rear speakers.

My workaround was setting up 7.1 (8 channels) in MIDI and instead of choosing back left and back right for the rear speakers, I chose side left and side right. This set-up worked with all the test files, but I still felt like it wasn't quite there. I suspect that with these settings, all it does is set me up for 7.1 Atmos without rear speakers, so my 5.1 rear speakers only really behave as the side speakers from an Atmos set-up.

What also threw me off for a day or so was that there still was no sound from the back speakers inside of Davinci Resolve Studio with this 7.1 workaround, but when switching to Fairlight it worked. I suspect the editing tab in DR is just not capable of playing 5.1.

I'm thinking of trying a different sound card. I was looking at the Asus Xonar u7 and Creative Sound Blaster x4. But none of these come with software for Mac according to their support. Without a Mac software they're plug-n-play, which I suspect is no different (or not much different) than what I have right now for testing purposes (the Logilink USB sound box). I'm running 3 channel optical out of it. SPDIF out (toslink cable) gives me no sound at all as of now. Any advice on the possibility of achieving better results with a more decent 5.1 external sound card would be highly appreciated.

I'm writing all of this in case somebody else stumbles upon this thread going through the same thing. Hopefully I'll be successful in this journey and able to provide some helpful information to the community.

Best,

Chris

Oh, and to add to this - the 5.1 (6 channel) set-up in MIDI produces sound correctly in all speakers now. The levels aren't greyed out anymore either. This was not the case when I wrote this post. So something has happened between now and then. Not sure what, but again I've been trying everything. At some point I must have changed something that now somehow made the Midi set-up work properly. Either that, or it just needed about 5 re-boots to begin to function properly.