I didn't want to start a new thread for this, so I'll ask here. What would be the best for a 18.5' x 13.5' x 7.5' room? A pair of doubles or triples? One corner of the room, the rear right, is slightly open to the rest of the house. The mains are set up along the short wall and I have total flexibility in sub placement. About how low will a pair of doubles or triples go in this room?