Need help. I've listened to both the polk and jbl, but still undecided. I have a Onkyo SR700 in the box ready to go. I'm looking at the following choices: Polk R30 front, Csi20 center, R15 rear, PSW 350 sub JBL N38II front, NcenterII, N24II rear, PB10 sub or N38II front, NcenterII, N26II rear, PB10 sub My room size is roughly 12'x18'. Also, can these sub's be hooked up w/ a dual RCA cable w/a "Y" adapter?