After a few years without surround, I've finally got the whole thing up and running. Surround from broadcast TV and DVD is fine, but from my Nvidia Shield Pro, connected directly to the TV, and then back to the 975 via ARC doesn't provide any surround. Best is 2-channel w/sub. Changing the surround setup within the Shield - three choices: auto, manual or none, gives the following. Auto is still 2-channel, manual is no audio!, and none is 2-channel. Could it be that ARC doesn't carry the surround info? A note on the configuration page for the Shield says auto won't work if the processor doesn't recognize the coding. Since it does for broadcast TV and DVD, I have to think that's not the problem.