Get rid of the carpet and use tile or wood. The carpet will dampen the sub.
That couldn't be more wrong; in a theater you don't want reflections, you want the room to be acoustically "dead".
Well, it's one of the great debates, but generally you want something like carpet. Even carpet the walls and ceiling to kill reflections, but then you can muddy the sound. Like I said, people debate this stuff ad nauseam.
Speaking in "generalities", even having wood floors, people will tend to cover them with area rugs in home theaters. You'll even want to put things in the corners to get rid of them; bookcases, dvd towers, furniture, etc.
OP; can't wait to see the results!