I helped a friend set up his surround system last night and I want to make sure I haven't missed something. He has the Infinity TSS750 speaker system, with satellites rated 120Hz at the low end. He has a Denon 1602 receiver, which does not have variable crossover and looks to be fixed at 80Hz. So there seems to be a frequency gap between 80 and 120. As far as I can tell there's no way to remedy this besides getting new speakers, right? Or a receiver with adjustable crossover?