These headphones are excellent. Well made, very good NC and fantastic sound when plugged into an iPhone or headphone amp.
.... When plugged into a Macbook Pro, with either of the cables, a huge amount of interference is present which makes them unusable. Is it the cable? the lack of shielding on the headphones themselves? or the Macbook Pro?
I tried another Macbook Pro, and 4 other headphones. Result? The other headphones don't have a problem and the Dr Dre headphones the other Macbook Pro had the same problem.
Conclusion? If you have a Macbook Pro, avoid these, or try them first. If you have an iPhone/iPod you will love them.
NOTE: Dr Dre Beats Tour have no issues on a Macbook Pro.