B&W speakers are just as good as what you put in them. The CDM9T is an excellent speaker, and will sound "good" with something like a 3802, but the amp section of the 3802 is not designed to power a speaker that presents a load that goes below 4 ohms. Powering them with a better receiver, or better yet, a separate amp will make the them sound fantastic. If you really want to power them with a receiver, I would not recommend that you go below something like the B&K 305 or the Denon 5803. Perhaps the Denon 4802, but at that point you are already losing out. I would even recommend something like the Outlaw 950/755 combo if you are in that price range.
I agree with what ManojM said, the CDM's need a little bit better amp, BUT they would still sound better than the 600 series, but not close to their potential.