So, you're referring to the high pass filter from HSU? They seem to allow you to specify two different crossover settings. Any recommendations? I'm not so sure I need a sub but it's nice to know that if I do decide to get one and I'm unhappy with the the default sound from sub output on the receiver that I still have options.

M60's
VP150
QS8's
HSU STF-2
Onkyo TX-SR805
Audiobytes for the PC