I just left the VP180 at 40 hz as that is where the mains are set to. This way I was assured of the best seemless front soundstage I could hope for, at least that was my thought. Not sure how much of a difference a 60hz setting with the center would detract from the front sound, most likely not much.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70