I thought the exact same thing that you did, and when I spoke with Chris from Audyssey, he told me the same thing you mentioned below. He said the Audyssey results are accurate and most people are just use to the bass being that hot.
It just didn't seem possible to me at the time, but recently I installed a measurement program (REW) and took measurements with and without the Audessey on (Direct mode). The measurements using the Direct mode, showed my bass was way up (+10db @ 25hz, +6 @ 60hz, +4 @ 80 hz).
I turned on the Flat setting, and re-ran the measurements, and the bass was brought in line to where it should be.
I then listened to some music know very well and did some A/B testing. The bass in the Direct mode was indded a bit strong, but it had zip to it. When I turned on the flat mode, I wouldn't say the bass was weak, but it lacked the zip.
To me, it sounded kinda like the difference between using 25wpc on your mains and 80wpc. Both will produce the right frequencies, but the 80wpc is more crisp.
I don't have a full solution, but I can say the Audyssey does seem to make the bass levels accurate.
I have also noted the the better speaker placement an room acoustices you have, the better Audyssey sounds. Maybe the more processing/correction Audyssey does, the more "punch" we lose in the sound?
Originally Posted by Ruin
While I realize that from many posts stating that the graphs are not able to show everything that is going on, a +6db showing at 63Hz would certainly indicate that it is boosting things in the regions, no matter what other things it is doing, and a -6db on the sub level is something that is readily visible, not magical, and is not part of the graph.
I still have never seen an adequate explanasion as to why SO many people get the bass pulled out from under them at the sub level using Audyssey. I seriously want someone in the know to offer an informed opinion as to this behavior. Is is technically correct and we all just like more "feel" so we run our subs hot, or is there an issue with Audyssey when you get into sub range.