I just got these a couple of days ago. I'm very impressed by both the sound quality and the design/comfort. The case says that they use carbon fiber for both the speaker housing and the diaphragm. I was curious if this is a similar design to the so called carbon fiber nano-tubes I've been hearing you guys rave about. I also read that there is a new line of JVC that has been out that is based on this design-could that be the carbon nano tube phones? Anyway, more about these later. I can say that they are really nice headphones. Great sound, but they needed a bit of a burn in at first.