I'm sure this is a newbie thing, but I've read and read and just can't come up with a solution. I have an AVR1710 HK receiver, Polk TSX550 Tower speakers and a Polk PSW505 powered sub. I want to get full range from my towers and only lows from the sub at the same time, not one or the other. I've tried putting the left and right at every crossover setting and get zero low range with the sub on. When running them as large and no sub they sound great. I read using the high level inputs and run from the amp to the sub, and then out to the speakers would give full range. This works, but it really doesn't sound very good. Am I missing something? I should mention that the sub is hooked up with LFE. Thanks for any input.