My front speakers are Yamaha A1738 (6 Ohm impedance) and my surround speakers are Sony bookshelf speakers (8 Ohm). I just mounted my surround speakers (about 2 feet above ear level to the sides of the primary listening position...which also happens to be also against the back wall) and they are really 'loud', drowning out my front speakers when there is dialogue as well as a lot of surround activity. Correct me if I'm wrong, but I think this is due to the fact that I don't have a true center channel speaker (the receiver is distributing the center channel between the L and R speakers). Since my two fronts are 6 Ohm Yamahas, I figured this center channel speaker (Yamaha NS-AC40X) was probably my best bet: Yamaha NS-AC40X My receiver is a Sony STRDE-945. Comments?