I was listening to my sennheiser amperior headphones all day, and I started to notice that there was a crackling sound sound. It happened at certain times in a song, but I don't think it was a part of the music though. It happens in my Bose AE2 headphones too but less so (and those are several years old. It happens when I listen to punk, death metal, and power metal. I've packaged up my sennheiser amperior headphones to return them because this seems like something wrong with the headphones, and I don't want to lose a return on this thing. I've kept them for this long though because I felt like they could be great for on the go. Perhaps all headphones in general make crackling noises?