Comparing Klipsch in-ear headphones

I've owned a set of Klipsch Custom-1 in-ear headphones for a couple months now, and I've been putting them to frequent use with my iPod. More recently, my friend DaveB got a set of the higher-end Custom-3s, and he was kind enough to let me borrow them so I could listen to the two models back to back, for comparison's sake.

The more expensive Custom-3s feature two separate "drivers" to produce sound, instead of just one for the Custom-1. I'm using the term "driver" loosely — the moving parts in these Klipsch headphones are actually called "armatures" and aren't shaped like traditional speaker drivers. With the Custom-3, one armature produces low frequencies, and the other produces highs; a crossover network sends the audio frequencies to the correct armature. I knew this difference on paper, but was curious to hear it for myself.

A quick note about the comfort factor
My Custom-1s are easily the most comfortable set of headphones I've ever owned, and the Custom-3s are identical in terms of fit. Both models feature an assortment of interchangeable ear gels. The gels have a slightly oval shape — Klipsch's research found this to be a better match for most people's ear canals than a perfectly round gel. Both pairs also have pliable built-in wire clips that go over your ears to hold the 'phones in place.

Listening comparisons
I used my iPod as the audio source, and just started grabbing random tracks. I encode most of my music as 192 Kbps (kilobits-per-second) AAC files. I feel like this setting gives me considerably better sound than the default 128 Kbps setting in iTunes. Despite the lossy compression of the source, I found that both sets of headphones brought out lots of sonic details.

On a cut from Bill Frisell's The Intercontinentals, the Custom-1s did a great job reproducing the vibrant tone of a Fender telecaster, along with lifelike acoustic strings and crisp hand percussion. Backing up the track and listening again with the Custom-3s, everything sounded a bit livelier and bass was noticeably fuller. The hand percussion wasn't just crisp anymore — it had the unmistakable low-end punch of a djembe.

On Beck's Sea Change album, string and synth arrangements felt big and lush with the Custom-3s. In contrast, the Custom-1s didn't sound as full, but Beck's soft, almost sleepy vocals seemed more prominent, and I found myself noticing more little details like the squeak of an acoustic guitar string.

The bottom line
To sum up the differences I heard: the Custom-3s had fuller bass and more high-frequency shimmer. Instruments had a more visceral, immediate attack across the board. It makes perfect sense, considering their additional cost. However, the Custom-1s presented lots of midrange detail, and on some cuts I found myself actually preferring the way they emphasized certain things, like the timbre of an acoustic instrument or a singer's voice.

Of course, sound is always a matter of personal taste. Have an opinion about these headphones you'd like to share? We'd love to hear it.