I have this headphone (actually these headphones) for several days. I had the SONY for years that I found excellent, but since I have the MX-400, I top up my other kid (!).
These are the headphones to the sound trs enjoyable, good bass (yes, really!), Treble that will not twist the ears, they are really good trs even if that's not all is comparable a "real" headphones. Trs is useful with an MP3 player, although sr, but also to record while hearing well the instrument is played. Like up in the ears, has not only repisse into the microphone.
It parat the wire coil is 6m Diameter ... But commentkifon?

And for less than 15, eh ...

Note that the version has a volume Intgr MX500 (on cable).

J-Luc

http://www.sennheiser.fr/downloads/fiches/mxserie.pdf
Bandwidth: 18-22000 Hz
Impdance: 32 Ohms
Distortion: <1%
Sensitivity: 119 dB 1mW
Length of cable: 1 m
Contents: 1 headset MX4, a cable reel