Thorsten,

I've actually set systems up like this. Systems that work superbly. As according to all reports does Titians. It is easy to sit in you little room theorising, but a little experimentation would not go amiss.

Personally I prefer to EQ the bass in such setups rather than treat the room, it's far easier. But given the space and appropriate traps such as the Modex units it is possible to treat down to 40hz and careful selection of the listening position will work wonders. Of course with digital EQ all of these concerns become a thing of the past. And of course not boundary loading an EQ'ed subwoofer is a very bad idea indeed.