[arande2]

I was wondering about the low crossover as well.

My mains extend to around 35hz and my surrounds extend to around 28hz (-6dB), but when I tried crossing my sub at 40hz, it didn't do much because it didn't have much low end output (UltraCube from Paradigm). I blew it very quickly because it had very limited output. With your design, however, it seems like a lower crossover would be fine. I'd probably stay closer to 50hz, though.

It really depends on how much amp power you have for your mains. At the time, I had only half as much power for them as I do now (Upgraded the receiver with store credit from sub).