I have the KSP-400 mains, KSP-300 surrounds, C6 center, 2-S6 for back 7.1 channel, KSW-300 sub. So we are running 5 subs here. A Denon AVR-5308 drives it all very nicely, very clean. A Samsung 58" 3-D TV, Apple TV Gen II, PS3 latest Gen, Samsung Blu-Ray/DVD player, FIOS Cable, Direct TV with NFL Package and Universal Remote which I program myself. Monster cable for all of it. TV mounted on the wall and all wires are hidden behind the walls. Very clean installation. I've wired everything myself.
Apple iPad which i stream music from my Rhapsody account.
The system is so loud, so clean it is amazing. The KSP-400's are amazing. Having the KSP-300's as Surrounds adds such a punch especially playing concert videos. The drums are incredible. I have the KSW-300 which is a 300 powered 15" sub behind the couch for added punch... I am not bi-amping or bi-wiring anything its just straight hookup.
Added the S6 speakers as back channels gives it a dimension that is so amazing. Those back speakers allow the Denon to play 6 channel matrix modes and boy what a difference. i can't imagine watching a scary movie. i don't think i would sleep for a month...
Well that is the system... i'll post some pics soon...