FWIW, I think that it's a common misconception that Audyssey sets bass (meaning sub) levels too low. I believe it is actually doing just what it needs to be doing. There is a much more detailed discussion of this issue in the subwoofer guide, linked below, but this is a synopsis. First, Audyssey's task is to set all channels, including the .1 (LFE) channel to play at the same volume at the MLP. It does that by employing a 75db test tone. And, although there can be some variance in the accuracy of the Audyssey mics, they will typically be accurate with respect to the equivalent volume of all of the channels. So, all of the channels might be set a decibel higher or lower than 75db, but there wouldn't be a wide variance between the regular channels and the .1 channel.
Second, once all of the channels have been set equally with that 75db test tone, the AVR will automatically reconfigure the regular channels to play at an "average" volume level of 85db at 0.0 MV (Reference). The .1 channel will play 10db higher than that. Peak volumes at Reference will be 105db for the regular channels, and 115db for the .1 LFE channel. So far, so good. The problem is that most of us don't like to listen at Reference levels, and as we reduce our volume to more normal levels (-10 to -20 is pretty typical) the bass frequencies fall-off perceptually much more quickly than those in our more normal hearing range. (Again, there is a detailed explanation of this phenomenon in the guide and you can also research the Equal Loudness Contours for more information.)
DEQ was specifically designed to help address that perceived loss of bass, at below Reference volumes, but even with DEQ employed most people find the bass somewhat lacking, so it clearly is not a complete solution. Most people seem to need to add about +3 to +6db in addition to DEQ. For those of us who prefer not to use DEQ, even heavier sub boosts are required. But, DEQ is a separate software system which many people don't use. Perceptually low bass levels is not specifically an Audyssey issue. Audyssey's job is to set all of the channels in a system to play at the same volume, and with the same timing, as measured at the MLP.
Audyssey has to start with all of the channels playing at the same volume in order to create the Flat curve and the Reference curve. If the bass frequencies were playing relatively louder than the other frequencies, there would be no way to EQ the audio system to a flat frequency response. But, once Audyssey has done its job, it's up to the user to decide how loudly he wants to listen, and how much extra bass he likes. And, listening levels and bass preferences can vary dramatically, so with or without DEQ, there would be no one-size-fits-all solution to bass levels.
If we all listened at Reference volumes, in a properly calibrated system, we would be hearing the bass frequencies in movies just as the film mixers intended for us to hear them. (DEQ would be completely neutral at that point.) At that Reference level, the only additional sub boost that most of us might want would be for purposes of individual preference. And, I suspect that most of those boosts would be pretty modest. But, since most of us don't listen at Reference levels, there is a nearly universal requirement to add bass to a properly calibrated and EQed system, at below Reference listening levels, just to get back to the acoustic balance that film makers intended for us to hear.
Last edited by mthomas47; 07-29-2017 at 12:03 PM.