I have a 6.1 system, but have always been intrigued by Logic 7. (I'm still hopeful for a < $1000 street receiver from HK that does L7 on 5.1 digital sources...) I guess the best way is to have 4 towers in back. But if I can only have 2 towers and 2 smaller speakers, which should be which? The surrounds are towers and the rears are OK to be smaller? And then for the smaller speakers, bookshelf direct radiators? How about small bipolars? (I have an old set of surround bipolars from Def Tech that my wife is currently using for her mains. BP-2's or something. I use BP-30s now for the surround towers.) Anyone know when the next gen of the HK 520 will be out? (Amazingly reviewed on audioreview.com. That's what put me up to this... ) Thanks!