My Shappires M3s without even pushing too hard can fill not only my loft area which is open below to the 15 x 20 family room. and the bass sounds better down there than up there due to the long throw the woofers see, from the front wall of the loft to the back wall which in this case is the family room below. We also sit outside on the patio off the family room and they sound great. So can they handle a larger room yes they can with no sweat and the bass will only be better than in a smaller room though due to the open baffle design, they work very well in smaller rooms.
The X series would do just fine also, I went with the M3s due to in the loft area how close I have to sit to the speaker, Clayton felt, in that case, the M3s would be better, if I sat further back than the X series he might have suggested.