Since I've had my Axioms, I've not had any back wall or right side wall, the Qs8's are mounted on the ceiling, and they sound great. Yours is not wide open like mine. Looking at your room, it doesn't really make sense that putting them in the correct location would give you poor results, 2-3 ft above ear position and to the sides for 5.1. For me the sound travels right through you.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85