My two pence worth, I'd avoid the sub route and buy monitors that can handle the bottom end by themselves, it's much more satisfying and easier to handle when the sound's all coming from the same place, even from a setup point of view in my opinion. I've got Event 20/20 bas actives, which have an 8 inch driver each and the bass response is smooth, deep and tight, I wouldnt need a sub, especially in the small room I'm using.