I won't dismiss the possibility that the synergy just doesn't work. I'm not really a JBL guy, never owned much of their stuff (the best from them I ever had was a pair of L7's, but MAN that titanium "sizzle" tweeter was just too much after a while.)
I would find it REALLY surprising that DCM's (at least their CX series which I have owned) would sound good with this Yamaha- just about any review concerning the CX-17 or CX-27 points out their surprisingly strong low end emphasis- I would think that would make them an even worse pairing with the Yamaha. I have never owned or heard the TimeFrames.
Here is my thread concerning the Soundwaves, some pretty good info in there, along with my comments concerning their pairing with the Sony ES receiver:
http://audiokarma.org/forums/index.php?threads/need-a-speaker-id-please.812366/