What decibel level do you listen at?

110 to 115 dB is too loud for anybody. You're going to damage your hearing with those levels, if you haven't already. Here's a table for reference:

Decibel Level (dB) Source
140 threshold of pain: gunshot, siren at 100 feet
135 jet take off, amplified music
120 chain saw, jack hammer, snowmobile
100 tractor, farm equipment, power saw
90 OSHA limit - hearing damage if excessive exposure to noise levels above 90 dB
85 inside acoustically insulated tractor cab
75 average radio, vacuum cleaner
60 normal conversation
45 rustling leaves, soft music
30 whisper
15 threshold of hearing
0 acute threshold of hearing - weakest sound

Here's an excellent loudness table.

Funny you'd pick Miles, I was listening to "Kind Of Blue" this afternoon at 72db and it was very enjoyable. Was that the best db level? At 70db-74db my system starts becoming dynamic enough to have energy/life.

As Almarg points out, if one listens mostly to classical or other types of acoustic music, the decibel level will be constantly changing, often over a very large range. Many audiophiles like to listen to their systems much louder than is actually necessary (I am not saying this is a bad thing, by the way - there are good reasons for as well as against). As I get older, I'm sure I will turn mine up more, but as a professional orchestral musician I am guaranteed to lose at least 20% of my hearing over the course of my career as it is, so I tend to try to avoid other really loud environments. Sometimes I will really crank up the volume on my system, but normally I try to listen at as low a volume as possible and still hear everything clearly. I have never used a decibel meter at home - I can tell you that I certainly don't listen at the decibel levels I constantly experience at work, which are definitely on the upper end of the range we are talking about. As Almarg said, this quite often reaches above that 105 mark - often more like 120 onstage depending on the piece. You don't always notice it, because we are used to it, and there is something about the physicality of helping to produce that volume that seems to mitigate the effect while you are doing it. The really bad ones are the pops shows where they amplify everything inside the hall completely unnecessarily, to the point where it is extremely loud even when wearing ear plugs. We usually beg them to turn the onstage monitors off or at least way down, but the so-called "sound men" never understand that they are actually making the ensemble problems much worse by cranking the volume up louder and louder. It just becomes noise after a certain point. If they would just turn everything way down, everyone could hear everyone else. Anyway, this is turning into a rant so I will shut up, just wanted to explain one very good reason why many musicians listen at lower levels than other audiophiles.