for those curious about burn-in factor and equalizinging these headphones (and some other concerns as well):
In my first review I found the bass too powerful, almost bloated for some music (i mentioned opeth having that alot). This goes away with burn-in, pretty quickly actually, and your ears get used to that factor too, and that problem only occurs really with my zen micro in the first place. The better the sq of your source, the better the bass. (ran out of dedicated amp the bass was just plain awesome).
Some of you will notice some sharpness and fatigue at first - former goes away quickly, latter result of the bass factor, which also goes away quickly.
They are not agressive about eq, but if you still find the bass slightly too powerful (my mp3 player has that problem of not having very good extension), you can easily roll down ~2 db on the lowest frequency and the sound should be perfectly fine at that point. I am enjoying a bit more bass so I left it on flat after a while. They also will reproduce slight detail boost if u pull the highs up 2 hz or so. The increase in detail mainly occurs in form of percussion cutting through better.
I have ran these by accident on volumes that would cause ear injury very very very quickly. They did not even distort. Nevertheless, stick to lower volumes and using big dedicated amps for these is silly. I used them out of total bithead and emu 1616 cardbus (no amp), and the sound quality points went to the emu, which is nowhere near as loud. These headphones DO NOT need an amp, but they do benefit ALOT from a good source. (mainly in the bass area, but all the other elements get a pleasant boost as well). Save your ears/batteries please guys.
Positioning for optimal sound quality:
They do not change much in sq when you move them around your canal, so please don't hurt yourself trying to put em in deep. (i am sure metal edges + ear canal are not meant to be together). When wearing them you will notice them slipping into a certain position - and form my experiments no matter how i try, the sq does not improve from moving them around. If you somehow block their little whole, they will become more grado-like, that's about it.
And my personal annoyance:
Try to keep your ears clean, the grills are ass to clean and I pulled one of em out by accident. Looked inside, found that the driver should be safe, but feel stupid now. Don't really want to send em off to Val's folks, I need these. The grill is attached on glue...(wtf?). If anyone wants me to take a shot on what we got inside there visible, drop me a message, but essentially the driver is hidden behind another, more coarse/thick grill that has bunch of large holes through it. That grill is located somewhere right above the grip on the phone. Not much to really see unless you got a microscope with lighting in it or something.