This is a bit nerdy, but here goes.... I have an all-dynaudio audience set-up (40 bookshelf rear, 72 floorstander l/r, 122c centre) and a REL 150e Mk2 sub. I drive this off a pioneer ax5i av amp. For DVD i pre-out this into a Krell 300i stereo amp into l/r. This allows me to use the l/r dyn 72s/krell/rega planet for better quality cd. Anyway, i was wondering what is optimum large/small/sub hi-lo/av amp crossover for all this. In particular, the dyns go down quite a long way: 40: 53 hz, 72: 48hz, 122c: 46 hz. My amp allows me to set crossover at 50 or 80hz, but not for individual speakers. At the moment, i have the l/r set to large, centre/rears set to small and the REL connected at hi (to come in below the l/r) and lo. The crossover is set at 80hz. I was wondering if this is getting the most out of my system. Should i also set the centre to large and crossover at 50hz? This is all very confusing. Anybody got any further advice?