There is another "HD 600". I'm wondering that it could be very useful for a lot of people here in GS. This is the Etymotic Research ER4.
It sounds at the same HD 600 level of quality. It is described like this at
ETY's web site:
... "The ER-4 MicroPro™ earphones are the next best thing to live music, with noise isolation far surpassing that of active-noise-reduction earphones. The ER-4's require NO batteries, and can be plugged into any audio source. Their 20-25 dB of external noise exclusion allows you to hear the full dynamic range of recordings without having to play them at unnaturally high and unsafe levels. The earphones come in three styles: ER-4S, ER-4B, ER-4P." ...
Best
Ari
Edit: They are not lying. I have one.