Owl's_Warder's got you on the right track here. With a center like that, I'd try crossing it over at 120Hz -- the center channel takes a lot of the load in home theater work, so you don't want a hole there. I'm guessing that the "external crossover" input bypasses the sub's crossover. That would probably be preferable in this case. As for the surrounds, there will be a lot of modes where they won't get much -- find a good demo DVD (some that spring to mind are the Battle of Carthage scene in Gladiator, the pod race in Phantom Menace, or Fellowship of the Ring -- which is also a good test for your sub, as the mix is very bass heavy). Same applies to the sub -- raising the crossover will probably help, and you'll need some test material that includes some low end material (SVS has some ideas here ).

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