In my living room, which is much longer than it is wide, I have an existing audio-only setup consisting of a pair of Fives and a Sub.  It sounds fantastic - the Fives are wall mounted on one of the short walls so they project sound across the full length of the room.

Now I want to add a TV with an Arc  to this room.  The only location that works for my living room is to put the TB+arc on one of the long walls, so the fives will be on the wall to the left of the viewer.

I will of course want to have my Sub as part of the home theater setup.  Based on extensive discussions in other threads,

I have already understood the fact that I can’t share the Sub with two different “rooms” - one home theatre room and one audio-only stereo room, which would be the obvious solution but it is what it is.  I’m certainly not going to buy another sub, so I need to come up with another approach.

If I configure the Arc as the center channel with the Fives as the rear surround channel, then will I be happy?  Will it be unacceptably weird to have the rear speakers be on the wall to the left of, instead of behind, the viewer?  I already know that it won’t be an ideal home theater experience but I have aesthetic constraints that are hard to explain in text.

My bigger concern is the audio-only music experience…  If I’m just playing music, is the Arc going to be silent?  Or will it behave like another speaker, and if so, how will I adjust the volume of the Arc relative to the Fives?