There's Multichannel Stereo mode, but it does not work if the source is multichannel. Arguably, it shouldn't have to, but I'd say there are still those scenarios where multichannel stereo is preferred even for a 5.1 source.
On March 8, 2014 at 16:25, FreddyFreeloader said...
+1 on all of these comments, especially the lack of an All Channel Stereo mode altogether, let alone a discreet code for sound fields, always bothered me alot. The new ones may have it, in fact I think they do but for years they didnt and it always made an install look bad when you couldn't at least force the rears to play when the customer started whining.