Hi Hay: Sorry, I misunderstood what you were saying. None of these stores seem to carry the Polk. The professional stores (as opposed to the Big Box stores) will probably allow you to fiddle with the settings of what they have setup, but I've never tried that.
I am now starting to get the feeling that I have expectations of a sub that a sub can't supply. I think I expect the sub bass to be as clean as the M60's playing back the whole spectrum of music.
When I turn off my sub, I'm just listening to the M60's. They are a delight to listen to. When the subs are turned on again, all the music from the sub sounds poor, and pollutes the M60's. But then again, maybe crap is what the people want.