dimension of the room is 2.8 x 4.5 x 11 meter ( w x h x l ). i am considering pb12 plus or pb12 ultra. someone told me to just get the 2 woofer versions, but they are out of my price range. i live in a south east asia country, so it is HARD for me to sell this subwoofer if i decided to upgrade later...that is why i am thinking of saving my money and purchase a twin ultra sometime later. but, given the dimension of the room, i got a feeling a single plus subwoofer should be enough. i already have a pb10isd in my living room which is has two big openings ( verrry large room ) and it does one hell of a job for such a cheap product to rattle everything. i think the fish in a small pond outside really hate it when i watch a movie. which one is better...a single ultra or a twin plus? or perhaps a single plus will do? so, guys, please advise. thank you.