I have been searching for about an hour to try and figure out why my 2012 mac mini will not send 5.1 over HDMI. I have attached 2 screen shots of the Ausio MIDI setup but most boxes are grey out. My Mac Mini is connect to the TV and then TOS cable to the AVR. I have tested and I know my Roku sends 5.1 no problem the same connected way. Anyone got any ideas? Thanks for the info.