Etymotic Research ER-4S Consumer Headphones

I bought my pair back in 2001 on e-Bay. I think I paid about $125 when these were on sale new for $250 - $300. I of course ordered a new set of latex ear pieces before I tried them out. I picked this model based on reviews and recommendations from http://www.headwize.com and http://www.headphone.com (the Head Room amplifier site). My goal was high quality audio in a compact package.

These were originally a companion to my Headroom Supreme Headphone amplifier. A good headphone amp is recommended for these since they are very inefficient. On my Ipod, I need to have the volume close to 90% to get a decent sound level. That caveat aside, they can work alone and Entymotic has a version that's designed for portable players. If needed, MP3 users can boost the gain (Google MP3Gain software) on their tunes to compensate for the ER-4S.

I'm not a freak about audio perfection, so I tend to listen high bitrate MP3s (220 - 270 Kb/s) created with the LAME encoder. Better than a typical MP3, but still a lossy format. I tend to listen to rock, fusion, and jazz.

Likes
The sound isolation is fantastic, especially in noisy environments. I fly a lot and on a plane these are a godsend. Once I was coming back from Hong Kong surrounded by newly adopted kids. New to flying and their parents, they started a round-robin of howls. With the headphones on, I easily slept through the flight to sweet sounds of classical music. I also use these when taking the subway in New York. They work well enough even when trains roar into the stations.

The audio quality is very good and close to my Sennheiser HD 580s. The major weakness on the low-end frequencies, but that's not especially unique for most headphones. The major plus of the sound isolation is that you can hear more detail than most headphones provide in out-of-home use.

Dislikes
These headphones are a bit tricky to insert properly. There are instructions and you can get the hang of it fairly soon. One watch-out is that the latex rubber ear pieces can soften over time and come off in your ear. That happened to me a couple of times and I needed tweezers to get the earpiece out. The solution is to replace the rubber when it starts showing signs of easy slipping.

A more problematic downside is the well documented "microphone effect". Any rubbing against the wires is transmitted as noise into the ear canal. I've had to do tricks like wrapping the wire over my ear when I take my music for a walk. Forget about using these for running. New models have a woven wire which is supposed to help, but I have no experience with this improvement.

Conclusion
These headphones have really become a part of my life. I love them for the personal space they create for me and they have made portable music a joy.

One major consideration: I think with this design, your mileage may vary due to ear canal fit and comfort. You can get a custom molded earpiece if needed, and that would solve any fit-related problems.