Originally Posted by hifisponge
By default, Audyssey corrects to flat LF at the measurement position.
Which, for better or worse, is perceived as thin bass. Hence the preference in these tests for room gain at the lower frequencies.Presentation Slides
Looking at slides 23 and 24, only two room corrections seem to be correcting to flat in the low frequencies: RC5 and RC6. So I'm guessing one of them is Audyssey, probably RC5.
If you look at the corresponding Spectral Balance plot of RC5 on slide 25, you'll notice that the listeners thought it was dropping as the frequencies got lower, when that's NOT what was happening according to the measurements. Reality vs perception (human hearing).
No wonder thin bass was an early complaint about Audyssey. Next go-round should re-test with Audyssey's Dynamic EQ (though I don't know if that feature is available in their external box).
By comparison, look at the spectral balance for RC1 and RC2. Both are tilted noticably downward as the frequencies get higher, but both were perceived as pretty flat.
If I were a manufacturer of a room correction system, I would be paying attention to these tests, especially when it comes to what listeners prefer. Harman is footing the bill, but everyone gets the benefits of the resulting data.