I purchased my Sennheiser HD490s a year or so ago, and after a few months noticed the right earpiece would produce a rattling noise, especially with certain bass frequencies. I took it back and got it replaced with a completely new set of HD940s. Now, I've found the same thing seems to be happening. It almost sounds like something is resonanting in the right earpiece at a certain frequency, one that seems to be prevalent in several songs I listen to.

Has anyone experienced anything like this? I suspect it's an environment issue, perhaps dust or something gathering in the earpiece and vibrating, however both times it has been on the right earpiece (the one without a cord attached.)

Starting to think I should just take these back and get some 495s or something completely different.

Also, if anyone knows if the HD490s can be disassembled (to some extent) so I can examine where the problem may be, I'd be very grateful.

Thanks in advance for any assistance

I have no exprience with the HD490's, however I have had an isolated incident of the same problem with my HD600's. The only time it happened was when I was experimenting with the "foamless" mod, and the drivers were exposed. A bit of dust or hair or something landed in there, and caused some distortions during only extremely low bass frequencies. The solution? I just blew on the drivers to remove any debris, replaced the foam and never took 'em out again.

-dd3mon