Pros - Well built, style-conscious, detailed yet engaging sound
Cons - Typically poor isolation, needs amping to sound its best
Intro: After searching for reviews on these headphones, and reading on swbf2cheater's MX vs PK comparison, I decided to jump the gun. When I unboxed the packaging, I got 2 pairs of foams, a shirt clip, and the headphones themselves. Nothing too special there. I felt that the design could have been more cohesive, but that it would also appeal to a fair amount of consumers. The earbuds themselves, though largely made of plastic, were very sturdy and well-built, and would stand up to a good amount of abuse. They were comfortable too, and didn't weigh my ears down. As with most other earbuds, microphonics were nonexistent. Sound: I had high expectations with these, as swbf2cheater's comparison assured me they would be better than the PK1's (which I heard for a short period at a friend's place). Thankfully, they blew my mind when played right out of the box on my sixth generation iPod nano. The bass extended very well, had great control and impact, and was delivered without any bloat or bloom. It didn’t bleed at all into the mids, either. I was extremely impressed with the vocals on the MX880, as it sounded so much more engaging than my HF5, but they still retained great intelligibility. The mids were very clear and accurate, but didn’t dominate the entire spectrum. The highs are yet another asset of the MX880. They were not recessed, but neither were they strident or harsh. I didn’t notice any grain in the upper mids/treble. The MX880 had stellar clarity and imaging, but fortunately, weren’t sibilant with some of my lower-bitrate rips. The presentation is another strong point, as it has the airy and spacious feel that compliments Sennheiser’s higher-end headphones. Conclusion: A brilliant headphone throughout. I prefer this type of sound and presentation to the HF5 by a long way, it just sounds so much more lively. While it is a smidge less clear or accurate, the Sennheiser’s are a great headphone in its own right, and I really believe more people ought to try out this earbud. Comparison to SE425: Bass: MX880 > SE425: The bass on the Shures extend quite well, but the Sennheisers simply have better texture and clarity. Mids: MX880 = SE425: Both headphones have prominent mids which shine in certain genres of music. Highs: MX880 > SE425: The Senns simply have more sparkle and are more engaging to listen to, while the Shures sound cold and a bit unrefined in the highs. Soundstage/Balance: MX880 > SE425: I simply prefer the MX880’s more even approach to the Shure’s bass and mids dominance. Overall: Sennheiser wins this by a mile. It is three times cheaper, yet it manages to do a lot of things better than the dual-driver Shure.