I've used these with my Ipod Nano (can't deal with ear-buds), and the sound quality is excellent for a foldable design. I have traveled with them and used them just recently on 14 hour flights to/from China. Very comfortable, even for my big head. They also worked very well with the in-flight entertainment system. The movies sounded very clear with plenty of good bottom end. The case is nice as it protects the phones well. Be patient figuring out how to fold properly to put them back into the case. The graphic instructions are printed on the case and are simple and accurate. ALso know that Sennheiser makes another foldable pair PX 200, I believe that are closed back - might be even better if they provide some isolation from outside noise.