Yet another post...
I have an AVR-2309CI. Everything is great except for bass levels. I know from my setup that I've done the Audyssey setup properly (using the Audyssey guide provided here on the forum). The issue is that with all Dolby TrueHD and DTS HD Master Audio tracks, the bass seems clipped. I've tested the 2-disc Avatar set switching from DVD to blu-ray and the DVD has bass more like what I'm expecting. I've tested my War of the Worlds DVD to make sure the problem doesn't exist with DVDs and it seems fine.
On Star Trek (2009) blu-ray, if I switch between the HD audio track and the non-HD audio French track, the explosions in the first attack at approx 2:30 are different in their bass levels. The French track is noticeably better where the HD track seems to be missing that lower extension altogether. There is SOME, but not the same.