A:Answer I think it should be a matter of preference Annonymous. The question you shld address is, do your towers to provide nice enough sounding bass reproduction for you? If so, I think 80Hz is a good balance. However, if you want to really enjoy the great sound of your new Klipsch sub (as I do) I would recommend setting a little higher. Others may disagree completely but, in the end it's "your" theater system and I think however it sounds best to YOU is ultimately what counts.