Shure SE215 break in period?? - Page 2

i thought the SE215s were Dynamic drivers?
 

Before my Grado SR-225i's and these Shure headphones, I was of that thinking.  In this case, I was switching between my SR-225i's and the 315's.  The difference was so pronounced I'm certain that there wasn't a significant psycho-acoustic factor at play.  I was also fully ready to put these back in their box and ship them back, so it wasn't a self-fulfilling prophesy either (i.e. a case of "I wanted them to sound better, so they eventually did").

I went through a similar experience with my Grado SR-225i's which was more subtle.
 

It is generally accepted that balanced armature drivers (which Shure, Westone, Etymotic, etc IEMs use) do not need any break-in/burn-in.

Dynamic drivers (Sennheiser, RE0, lots others) DO need break-in/burn-in time for the speaker cone, however small, to get used to moving (think of a big speaker cone).

ALL IEMs need "brain" break-in/burn-in time -- that is, your brain getting used to a new sound signature and accepting it (or not) as "normal" sound. 

As long as people's suggestions for burning-in are kept within reasonable lengths of time, say 2 to 10 hrs, there's no harm done playing some pink noise moderately loud. It is when people start talking about 100-300 hrs as was/ is the case with the IE8s or over 500 hrs for the HD650s, where things just get absolutely ridiculous.

Most people seem to ignore the effects of psycho-acoustics (or brain burn-in) and the fact that we don't always hear things the same way even with gear we've had for a long time, much like the food we eat or beers/ wines/ juices we drink, which don't always seem to have the same taste. By this I mean that even today there are times when I find my ES3Xs (with over 1000 hrs on them) to be simply amazing, out of this world, and others when they sound just 'very good', ie I'm not always equally 'music hungry'. When I am 'music hungry' all my IEMs sound better, not necessarily great, but definitely better. There are other variables to take into account but won't go into them (again).