As my first post, I would like to thank all of you for this forum. It has already improved my home theater and I've only been lurking for a month. Now for the newbie question: In a 7.1 set-up are there two main rears and 2 surround rears or are all 4 rear speakers treated equally? How about the fronts in 9.1 (a center and 4 fronts or a center, 2 fronts, and 2 surround fronts?).