I'm thinking about going with the package that has the CBM-170 fronts and surounds, CMT-340 center, and the Hsu VTF-2 MK2v sub. The room is going to be around 21 by 15. My question is do I need to have the CMT-340's for the fronts or will the CBM-170's up front work just fine? How about the sub in this size room, will it work good?