Well Guys I have sold ALL my subs within the last month or so. So now I am subless Anyway I will of course have to build a new one! I plan on doing a dual Shiva sonosub like Mike K's. i.e. 48" long piece of 24" diameter tube with a 24" long 8" port. One driver on each end. My question arises when it comes to cancellations due to room interactions. I have heard Mike's on several occasions and like what I have heard! My only concern is my ceiling is only 8' not a vaulted ceiling like his. I wonder how this design will react in my room? I know there are formulas to figure out cancellations and bumps, but frankly I don't have the patience to figure them out. So, I ask you if you have a dual sono in a room like mine what can I expect? I'm not so concerned about bumps as I am about cancellations. Bumps can be tamed with the Behringer FBD. Any experience would be appreciated.. Oh yeah I do know it will have to do with positioning of the sub and the listening position. But I think there will at least be a constant peak or suckout at the listening height. I hope I made sense here.