Yeah i haven't got the room for that size in the devastators - Available space is 800mm wide (31.5”), 560 high (22”) and ideally 400mm deep (16”). I can flex these measurements slightly although the 22” high runs from floor to directly under the TV so that is absolute maximum. That is the reason why i looked at the 15" in them. The space i have for the sub that would handle the lower frequencies is a bit bigger but would need disguising as a large side tableIt all depends on how much you're willing to spend and the space you want to take up etc. For example you could build a UM18 ported for the low end and add and MBM for midbass or just build some ported B&C21s (what I have) for around £1400 and have all the midbass and low end you will ever need! A pair of 21's in some devastors would be amazing!