This gets complex really quickly, but hearing is both psychological (interpreted or interpolated) and physical.
Noise (sound you don't want to listen to) does more damage than the same sound when it is welcome.
Harsh, non-harmonic sound is more damaging.
Examples in music include cheap amplifiers or overdriven amps, as well as all inharmonic sound.
NVH has actually been coined to refer to this issue = noise/ vibration/ harshness.
NVH is more important than volume.
The theory is that we don't hear some frequencies as well at lower volumes, so this is why people turn up volume.
http://en.wikipedia.org/wiki/Equal-loudness_curve
Whether true or not, we have a craving for accurate sound.
Physics being what they are, most home speakers can't produce lower bass, and distort when producing what bass they do produce.
Worse, most music is filtered for lower bass.
Digital sound is also worst at the lower frequencies.
I found when I moved to my better speakers, that i was satisfied with the bass I didn't know I had been missing.
Perhaps more important, larger cone surface reduces distortion dramatically.
(I had actually asked about this issue in class years ago, as my high frequency horn drivers weigh nothing and bass speakers are heavy and heavily loaded, as well.
I was told that we don't hear bass dixtortion as easily as high frequency distortion or inaccuracy.
WRONG!!!)
To my shock, I actually prefer listening at even lower levels as long as the bass reproduction is adequate.
Lower volumes reduce distortion even further.
Less driver excursion = less distortion, harmonic and otherwise.
Trying to solve apartment issues for people with poorly built walls, I actually suggest upping their lower bass capability and turning down the total volume.
Granted, this may not be an easy solution, but physics are physics.
No matter what mono subwoofer bullshit companies try to sell these days, don't be fooled.
(And never use a mono subwoofer except for mono sound.)
Good sound requires good amplifiers and good speakers.
I can tell you how to save money, but there are no shortcuts to decent audio.
The speakers posted spec 15hz to 23Khz, and those are not fantasy figures like most specs.
To reach that level of accuracy, I recommend four 18" bass drivers or equivalent, say by using many smaller drivers.
Preferably double that.
And I believe in live rooms too, even for recording.
All speakers distort less at lower volumes.
All speakers are more accurate at lower levels.
HOWEVER,
big pa systems are well past these levels now and are capable of very low frequency bass.
Many of the sound systems on the playa are very capable of producing deep and accurate bass without blaring at annoying levels for long distances.
The bass would still penetrate in the area.
Yes, we have proprioceptors in many areas of the body, but there are dimishing returns with using audio as a stimulus.
Audio, especially in open air is a logarithmic curve to add volume.
Nexus or the people that have produced their sound go into great detail on their webhouse about concern for accuracy over noise, and the pointlessness of excessive volume.
Still too loud on the playa, but they have thought about these issues and seem to understand them.
I went to a regional that was so loud that I could either not go into the active area or wear earplugs, or suffer.
Conversation was impossible.
No one outside of a few dancers wanted those levels.
At the nexus point between the speakers, I could feel my insides resonating, obviously
very dangerous levels.
The dance area was maybe thirty feet, but everyone had their fun pissed on.
Much louder than burning man, on average.
It wasn't pleasant.
Why?
I like the people at the regional and have no plans to return.
