I have an old HT, approximately 1990 vintage, one of the original THX certified in my area. Snell's first THX certified speakers, matched fronts, center, 2 subs and dipole sides, Lexicon CP3-a processor THX & Prologic 1. It's time to upgrade the pre/pro. I have not kept up with the advances in technology. I don't want to change my speakers which are all built into the room. Do I need a THX certified PRE/PRO to match with my speakers? Will these speakers be OK with the newer 5.1 processing options? I'm especially trying to figure out the role of dipole sides in the new mellenium. Thanks for your opinions and time educating me!