Ok...finally found time to actually comment...can't be done from a plane/taxi.
'' It should thus come of no surprise that the ER-4PT has some of the best instrument separation around. It never failed to render different instruments, no matter how busy or congested a track may be.'' - thatonenoob's Review
I have owned my pair of ER4pt for about 2 month now.
And I must say that i do
not really agree with the above statement. Yes, the ER4 is
quite clear and the treble extended without being sibilant.
Yet for me, seperation and placement is something they lack (to a certain extent). I find that the ER4 would be better off with a dualBA setup (dual for phase coherence sake), because this would probably improve the separation between instruments.
To the ER4s shines with simple and fast instruments (ErHu - Chinese fiddle), where the fast decay makes everything sound precise and on-the-point.
They have problems in passages where there is a lot going on (electric guitars + drums + singing...).In those moments I feel, the single driver could keep up with the pace, but can't handle all the different sections/instruments/layers at once. It results in a strange situation where the sound is fast, but also muddy at the same time.
In addition to that, i do not hear what people mean, when they talk about the ER4s'
microdetail
This being said, the ER4 is an iem which appeals to me personally, not too much due to its technical proficiency, but rather because its overall nature is uncoloured and well extended in the treble. It is a signature i very much like - yet to me they do not seem overly special. I won't be giving it away anytime soon.
....Let the hating begin...