Hi! I'm planning to build an IB for my HT, in the house that I'm moving to (my fiancée is coming along aswell, but is not allowed to voice her opinion on the matter ). What I don't know is whether or not 2x15" subwoofers in an IB-setup will be enough. The IB will be placed upstairs, with its' outlet in the livingroom (downstairs) - I'll simply put a large closet to good use The livingroom dimensions are approx 8,5m x 3,2m, height 2,4m (equals approx 27,8ft x 10,5ft, height 7,8ft). Is there any likelyness that the IB will displace enough air for this room, or would I be tremendously better off if I choose to use, say 4 or 8 15":ers. I already have 2 of the woofers, but I will probably be able to buy some more if I wish to do so. I'm thankful for any input or ideas anyone might have /Mats Kellberg PS. I don't if it's of any importance, but the data for the woofers are as follows: Vas = 550 l, Qts = 0,54, Fs = 21 Hz.