I don't have any rear surrounds. I could if I decided to stick with the Mod2 center channel and move the extras to the back for a 7.1 set up. By the way Mod 4 is 8 ohms. I was just looking for feedback on sound quality. I know you try to be consistent with yout left, right and center channel but that Onix center channel would have no where to go...much too big