Have you tried mounting those speakers on the back wall? If you haven't, try it. You might like how it sounds, which would solve your problem.
FWIW: I know two people who have their main listening positions (MLPs) close to the back walls and use a similar type of speaker for surround duty (one uses Axiom QS4s, the other uses Paradigm ADP-390s). In both cases, the speakers are mounted roughly 6' up and, in both cases, the set-up sounds good / works well.
Last edited by eljaycanuck; 06-30-2016 at 01:41 PM.