I want to love these, because I'm really impressed with the underlying sound. However, I've got some serious background hiss/white noise regardless of source (and I've high end cans to compare them to, so I know it's not garbage-in-garbage-out). Seems to be consistent, regardless of volume, and only when audio is actually playing, not when they're inserted. I think that last bit rules out feedback from anything, so I'm left assuming the IEM's are the problem. Suggestions?