How loud is loud, What DB is actually loud?

http://trace.wisc.edu/docs/2004-About-dB/

Another source of info.

Also, in simple terms, tbe 85 dB rating is generally measured at 1 meter from the speaker with a 1 watt input at some frequency. A speaker will certainly play louder than it's rating; however, a speaker with an 85 dB rating is someone less efficient than many speakers so it won't play as loud as a speaker with, for example, a 91 dB rating.

I have a friend that listens to his musics very loud at times. In high school he put in ear plugs in his car to "feel" bass and actually got a nose bleed out of the deal. When we shared an apartment he had the system in his room cranked up so loud that a lady from the next building (about a 30 foot air gap) came over to complain. I requested that she wait while I got him since he wouldn't believe the complaint if he didn't hear it from her. In any case, we used a dB meter once to check the listening volume because he wanted to see how it compared to OSHA recommendations for hearing damage. I don't think he even exceeded 95 dB (probably not the loudest he ever turned it up) on the meter. We were both surprised as we expected a higher number. Concert volume is stupid in my opinion.