questions.... i have a b&w 10inch sub. but im not sure how to set up the av. i use 2 large front speaker [jbl hls 620] and im not sure how to set the speaker size. should it be on large or small speaker setting? what is the actuall difference between these 2 modes and how much of an effect does it really have, or in other words , does it make that much of a differnce? 2. how important is it to place the speakers on a carpet?