you would let Audyssey setup run and review what results it gives you. most likely the m80's and possibly the Vp150 will come back as large, set by the receiver manufacturer after Audyssey reports its results, you will go back in the receiver and change that to small. Then, most likely have to bump up the crossover for those speakers, 60-80hz for the m80's, and 80hz for the vp150. I think the LPF you talk about is something that manufacturers have added recently to receivers. The Dr's at Audyssey say they don't agree with having this, as it confuses people. I leave mine at 120hz I believe, which is what the good Dr. recommends, as some material extends beyond 80hz.
