Originally Posted by IAATM
It's my understanding that the chirping is the DAT tape "spinning" in the drive. In other words, it is the background noise the correlates with the RPM of the tape passing over the "head" or "pickup", to use an analogy from the old days of analog casette tapes.
It is a constant background signal, meaning that as you turn up the volume, this chirping does not get louder and the music actually drowns it out. If you turn the volume all the way down, the chirping becomes more apparent, because the music is not there to hide it anymore.
You're right. I don't have the problem with my Senheisers, but my Sure's are so efficient I have to turn the volume way down, hence the audible chirpping. To get rid of it, I have to turn the volume up way too high.
Moral of the story - get a less efficient headset.