Just traveled from KSA to Virginia and listened to them ( HP50)through airports and on the plane. At one point the earphone cups were hot I guess from me falling asleep with them but that was me having slept on the plane for 5 hours. Listening to them with the E12 DIY amp makes a big difference on sound signature. The amp made it for me on the HP50's . I also had with me a set of IEM's from Shure ( SE215) but the sound was small if that makes sense. so couldn't compare. Every once in while still like people have said here I would pick up the creaking sound of the design of the HP50's. I must not pay attention to that detail as much. I agree with Skyfall on his comment .. trust no one but only your ear . good way of putting it.