Summary: Comparing to my 4 year old Klipsch Reference ONE headphones, I wanted a reasonably priced pair of headphones I can use at work. When comparing the sound output, the Sennheiser is clean but about 40% as efficient as the Klipsch.
Pros: Great value
Cons: low quality output volume needs to be set very high
Summary: Not a huge fan of these, really. I will be keeping them for my home studio (editing, etc) but I won't be using them for music. You could quite easily find a pair of in-ear earphones for £10 and get the exact same sound quality, except louder.
Summary: I purchased this on March 1, 2014 after seeking opinion from my colleagues....while the quality is between OK to mildly good...the sound quality is pretty ordinary. The sound even cracks while listening on high volume and the bass isn't deep enough.
Summary: I had trouble finding headphones that fit over my ears (I hate the ones that crush your ears against your head!) so happily purchased these given they met this requirement and Sennheiser appear to be a good brand.