Both of those components you are refering to are likely on the bright and analytical side (Refering to the Yamaha from past experience). I would NOT mate them together personally, as they don't compliment each other well(speakers/receiver). I'd go with a warmer more forgiving sounding receiver in the Denon if you already own those Klipsch speakers. The old Synergy series speakers weren't as bright and hollow as the newer series, FYI. I know, I've owned and compared em both.
Also, the new Denon's have an INDISPENSIBLE Audyssey MultEQ system that's superb, and much better/more effective than the Yamie's.
Also, the new Denon's have an INDISPENSIBLE Audyssey MultEQ system that's superb, and much better/more effective than the Yamie's.