Just had to comment on these headphones to stop other people making the same mistake. I've had perhaps 25 pairs of headphones in my life and without doubt these (for the money) are the most pathetic. Where do you want me to start?? Well lets start (and finish) with the phones ability to reproduce the sound of a drum. I found it more realistic to hit the side of a cola tin with a pencil. That is how bad the reproduction is. Another huge problem is with volume and general base. Its near non existent. These phones are incredibly quiet and as for noise cancelling, I can hear my thumb rub my fingers at full volume.
Now it may be I have a faulty product here (No particular reason to think so). I shall try and return them on the basis of pure laughter.
Quite honestly you would be much happier (and better off) sticking with the boxed ipod or walkman phones if this is your intention.
As for Sennheiser- well I find them expensive but generally ok. The MM 55i's are however nothing more than a joke.