Regarding transportable, it should be noted that you can not fold the headphones.
At the sound, I find the excellent (the bass is quite pronounced, it does not bother me, but I warn). Insulation is good (but not exceptional).
The wire has a small remote control with a button (play-pause-answer the apper-hang) and a microphone.
Note also that the cable is Y: a wire in each ear. This cable is flat and does not even nodes that I wound up anyhow (that's cool), and the jack is bent (that's cool too, it is more resistant to tautness).
Personally that's exactly what I wanted, and for the price I'm not disappointed. Remains to see if the headphones take long!
EDIT: one month later, still ok, awesome helmet!
