Clipping can be induced by adverse behavior of your player on particular track. It may have not been picked up by other equipment - which for whatever reason just is not sensitive enough in particular region. Clipping artifacts for example tend to be treble-based, which Shure E500 is not strong in.
He reports the clipping with "all" his iPods and iPhones. Assuming it is the source, that poses a problem for Westone, as those are likely sources people will use with their equipment. I still doubt the problem is with his iDevices.
|On the case of amplification - if your mp3 player is on max volume driving an amplifier, it may not have enough headroom. Some equipment accounts for that by softening, other equipment just goes into good old distortion. Yours may be the latter.|