After reading several recent posts on this thread, I decided to go back to the Cliff Notes, which begin the Guide, and add both more detail and more emphasis to a number of the points. For those of us who are relatively new to HT (which has been all of us at one time) there is a lot of information to take-in all at once, even in the very abbreviated Cliff Notes format.
Please read the Cliff Notes several times, and let the information sink-in gradually. Some of the concepts are more complicated than they appear to be, and understanding them is important. For instance, almost everyone is going to need to add some subwoofer boost for 5.1 movies, after running an Audyssey calibration. That is not a flaw in Audyssey's operation. It is an intentional design decision.
Audyssey is attempting to make all of the channels in an HT system play at exactly the same volume, at a fixed master volume level, which is called Dolby/THX Reference. After an Audyssey calibration, that volume level is 0.0 MV. But, very few of us actually listen at 0.0 MV. That is very loud for most people, even with room treatments. The average AVS volume level is probably somewhere around -15 or -20 MV. And, at that volume level, we don't hear bass frequencies nearly as well as those in our normal hearing range of about 500Hz to 5000Hz.
So, as volume levels drop below 0.0 MV, bass frequencies drop away faster than other frequencies, and we need more bass volume to hear the bass in equilibrium with other frequencies. DynamicEQ (DEQ) is intended to compensate for that, to some extent, and many people find it very helpful. That's strictly a YMMV issue! But, even with
DEQ engaged, the average subwoofer boost used on AVS seems to be about +3 to +6db. Without DEQ, the typical subwoofer boost would be much higher than that.
And then, there are the issues that Gary mentioned, such as the variances in recording levels, how much bass is embedded in the movie or music to start with, and the issues of personal preference, that we need to consider. How much bass we prefer to add, post-Audyssey, will inevitably vary by individual, and it may be both room-dependent and content-dependent. But, it is important to understand that it is absolutely normal (and typical) to add subwoofer boosts after an Audyssey calibration.
I appreciate the nice comments about the Guide, from my friends Gary and Ken, and I wish everyone a Happy Holiday Season!