Originally Posted by robm321
I have the HF3s which I think are the same but with a mic, and they do not hiss. I would have them replaced. Also, you may want to try a different source to make sure that isn't the culprit.
I had tried several sources, from iphone apps to sine gen on computer, all of them makes the same hissing sound at around 4500-5500hz, now that it is confirmed that the hissing sound is not normal, I would probably get them replaced when I have time. Thanks a lot
Originally Posted by nihontoman
try listening to a frequency swipe. if the sound suddenly becomes loder while in that range, than it's not the earphones but the resonanse with the ear canal. everyone has that going on so just turn down some decibels in that area and the "hiss" should go...
I had tried a frequency swipe(sine gen), its not that it is louder in that range, there is an obvious hissing sound in the background in that range but not in the other freqeuncy.