Can't you move the sofa to align closer to you surround outlets, then move the display a bit forward. I read that even direct firing surrounds would yield better enveloping ambiance when postioned closer to about a foot behind your listening position and slightly higher than your ears. It's the rears in a 7.1 set-up that should be set further back, ideally at the back wall, while the surrounds are at the sides along your listening position. But you can try, you may just have to increase the volume of the dipole surrounds. Direct firing speakers located farther back sounds best with discretly recorded multichannel music though,but not as good with movies. Having said that, they're not really hard and fast rules, just recommendations, as you can always experiment with speaker placements that would sound best for you.