The Deftech speakers are OK, at least the front stage ones. I have never been a big fan but not a hater either. Their subwoofer is pretty bad. I think you can do much better. I would be looking at some
Ascend CBM-170 with a
CMT-340 center and maybe some
SVS Elevation speakers for surrounds. For a subwoofer, I would be looking at a
Hsu VTF3 mk5, that will blow the Deftech sub out of the water so badly it is on a different planet of performance. Just an incomparably better subwoofer. Even the
VTF2 mk5 would annhilate the Deftech sub without even trying. The Denon receiver is fine, and the speaker system I outlined should stomp on the Deftech system pretty easily.