The question about multiple subs is going to depend almost entirely on your room (both size and configuration). My opinion is that the mid-level subs from SVS, Hsu, Axiom, Elemental Designs, etc. would be a good place to start. You might find that one EP350 is quite sufficient. One of the great things about doing business with Axiom is that if - after getting an EP350 - you decide within the 30 day trial period that you really just want the EP400 or EP500 instead, they will make it painless to upgrade.
