I've noticed something that's got me a bit confused, and I've been doing some experimentation and research. I'd like to see if anyone else can confirm what I'm seeing.

Occasionally I can hear distortion when I'm using certain pairs of headphones. And this isn't distortion caused by the playback amplification, it seems to be entirely in the speakers of the headphones themselves. And the odd thing is that it seems to happen equally at any volume, from whisper-quiet to very loud. Normally, you'd think that frequency-induced distortion of a speaker would decrease with reduced amplitude, but in this particular case it seems to happen even at very low volumes.

I noticed one particular song in my collection which clearly induces this distortion every single time for me. I have posted a 10-second snippet of the song, "Samurai" from The Pretenders' album Viva el Amor, at my web site here.

I'd like to know if anyone else gets distortion when this is played back on their equipment. The distortion clearly happens for me as Chrissy sings the word "champagne". It's not subtle, either, it manifests itself as a clear, plastic-y sounding crackle for almost the entire time she's singing the word.

Here's the odd part. This distortion doesn't show up at all whatsoever on any full-size speaker systems I own. Not on my Altec Lansinc computer speakers, not on my boom box, not on my car system played with the empeg player, etc. It only shows up on headphones, and only on certain pairs of headphones.

I have also ruled out playback amplification, because I can hear it if I plug the headphones straight into the RCA's of the empeg, but not through any full-size speakers driven by the same RCA's. The problem also manifests itself equally whether or not I'm playing the Empeg piped through my soundcard or whether I'm playing it from WinAmp, so it's not the empeg. And again, full-size speakers do not play any distortion, whereas the headphones do. Even a full-size set simultaneously plugged in with a Y-adapter to the same line the headphones are plugged into: Speakers don't distort, headphones do.

All headphones except for one, that is. I own exactly one pair of headphones (out of several) which don't manifest this problem. They are a very old pair (over 15 years old) of walkman-style headphones from a no-name company called "Gemini". They play the music perfectly with no distortion, just like a full-size set of speakers does.

Does anyone know why this is? Even my full-size, around-the-ear, $75.00 big headphones distort this piece of music. What is it about the frequency content of this particular song that makes headphones angry?

And why only headphones? Why don't some full-size speakers distort? If it were just a question of cone size, well, the big over-the-ear headphones have a larger cone than the Gemini headphones which don't distort.

If it was just a question of bass response, I'd understand, but this piece of music has less bass than many pieces of music I play which don't distort the headphones. And the in-ear Fontopia headphones I just got will reproduce incredibly low frequencies quite clearly in my tests (lower than most of my full-size speaker systems), yet they show the distortion on this song.

If it was just a question of volume, I'd understand, but the distortion seems to happen equally at any volume.

I have a guess about this, but I'm not sure if this guess is close to reality. Maybe some of the audio tech people on this BBS can tell me if I'm warm or not... Many (most?) headphones use thin plastic mebranes instead of actual speaker cones to do their job. Maybe there is a certain combination of normal frequencies in this song that, when combined, cause a resonant standing wave at a much lower frequency which this plastic membrane can't handle. Does that sound right?

Can anyone else confirm my findings?