It was two years ago that I got my Etymotic Research ER-6 Isolator Earphones, and I've been using them almost constantly since. I got them because I wanted very high quality sound reproduction without bulky or very visually obvious headphones. My previous experience with earbuds had been pretty poor. I tried the cheap earbuds that come with various CD players, and have not been at all impressed by the sound reproduction. Now I'm not a total high-end audio snob, but with good speakers I can hear the difference between even a 320 kbs MP3 song and the original wave file, and I can tell 128 kbs MP3 blind any time. I listen to a wide range of music, including classical, and I find classical music in particular challenging enough for speakers and headphones to reproduce so that it is a good test for how well a pair of speakers or a pair of earphones sound.

When I got my Etymotic Research ER-6 headphones and first tried them, they come with both a more or less permanent plastic earpieces in three different sizes, as well as reusable foam earpieces. I personally could never get the plastic earpieces to feel right, so I just use the expanding foam earpieces instead. That has worked with really well for me, with the only downside that the foam wears out after six months or so. This isn't a huge problem because Etymotic Research makes replacement foam parts which you can get here on eBay for very little money.

These sound reproduction on the ER-6’s is uniformly excellent across a wide range of music styles. It reproduces the full spectrum of sound in a fairly neutral manner. That means that if you listen to bass-heavy music exclusively and want the bass grossly exaggerated, you might be disappointed. On the other hand complaints that sometimes read about the bass being completely absent is simply not the case. Weak bass can result if you don't have the earphones properly all the way into your ear, but if you get them seated right they sound excellent all the way from the top to the bottom of the sound spectrum.

I found that I can listen for even six to eight hours straight with minimal discomfort. Another unexpected benefit has been on airplanes, where the isolator aspect of the headphones serves to block out most of the ambient airplane noise. I've been grooving along to my favorite tunes when the stewardess comes by, and I pull out an earphone to ask for an orange juice and a loud rush of background noise greets me, reminding me of how well these earphones block out the airplane noise.

In all I highly recommend the Etymotic Research ER-6 headphones for anyone who doesn't mind having things in their ear and wants uniformly excellent sound reproduction. These earphones are well worth the price.