I just upgraded to an Onkyo HT-510 6.1 receiver after years of living with my Sony two-channel set. I'm holding off on the rear speakers until I move because the room set-up makes wiring them difficult. I would, however, like to add a subwoofer and a center channel speaker to my set-up to get some advantage from my new HT setup. My old front speakers are AR TSW 210 bookshelves. I have really grown to like them and they sound good with the Onkyo. I realize that matching them with a new center channel speaker (and later with rear speakers) would likely compromise my system's sound but I'm somewhat loathe to give them up. Is there any way I can minimize the timbre-matching issues with a new center? Or do I just need to bite the bullet and get a matched set of front speakers (perhaps keeping the AR's as a B set for listening to music - my receiver usage is split about 50/50 between music and video)?