I recently got a Pioneer Elite 84 receiver, pretty much specifically for hddvd and blu ray. I have the Toshiba A2 and a PS3. I already have gotten the firmware update, and turned the sub boost on. My question is, I had the MCACC on while watching Batman Begins, and the volume seemed really low, and the soundtrack lacked "punch". So I turned it off, and it sounded much better. I also watched Casino Royale with the MCACC on, and it sounded just fine to me. Is the difference attributable to the compression of the Dolby TruHD track vs. the PCM uncompressed, or is it because of the settings, or what? I would like to keep the MCACC on for all of it, but if I must switch it off, then so be it. I did use the mic to do the auto setup.

I recently got a Pioneer Elite 84 receiver, pretty much specifically for hddvd and blu ray. I have the Toshiba A2 and a PS3. I already have gotten the firmware update, and turned the sub boost on. My question is, I had the MCACC on while watching Batman Begins, and the volume seemed really low, and the soundtrack lacked "punch". So I turned it off, and it sounded much better. I also watched Casino Royale with the MCACC on, and it sounded just fine to me. Is the difference attributable to the compression of the Dolby TruHD track vs. the PCM uncompressed, or is it because of the settings, or what? I would like to keep the MCACC on for all of it, but if I must switch it off, then so be it. I did use the mic to do the auto setup.I'm not sure if I can help answer you specific question, but when "The Departed" was tested (The only title available with a PCM track for Blu-Ray and a TrueHD track for HD-DVD) it was determined that the TrueHD track is encoded 5-7db quieter. I have found this to be pretty consistent when comparing TrueHD to DD+ or DTS downconverted tracks as well.

Well, the other thing is, when I switched off the MCACC on BB, it sounded so much fuller than it did with it on.

I would recommend keeping MCACC on, sometimes it's easy to mistake full sound for louder. In general I've found most Warner titles to be recorded at lower db levels, just crank up the volume for the Warner HD DVDs

In my opinion, the MACC does more harm than good. Sound is much fuller and more satisying with it OFF than with it on. I don't put much faith in room correction software, at least at this end of the market. Correct the room first I say (of course, assuming you can!).