People always toss out driver burn-in (or break-in) as a given, but there was a guy on the newsgroups (rec.audio.?) that said he had done mucho testing on loudspeakers and that after being played, the speaker went back pretty much to the state it was in before being played, or at least alot closer than you would think. You would think that sooner or later, the coefficient of elasticity, etc. would be permanently changed. Dunno, just thought I would toss that out there.