The design of the Westone UM2 earphones is excellent overall, so we'll start with our one gripe: The earpieces are at least double the size (about 0.75 by 0.75 inch) of any other earbud we've used, so if your outer ear is small, expect them to stick out a bit. It's not uncomfortable, but it can look a bit silly. We're quite fond of the clear casing of the pieces, though, as it gives a neat look into the inner workings of the UM2s. Plus, the cord, which is thin and twisted, seems sturdy and offered no feedback from rubbing against our clothes. Also, at 48 inches, it proves the perfect length for our tastes, and it's black, a minor detail but a refreshing change from iPod white. Finally, the foam ear fittings, of which Westone provides two pairs of two different sizes, are comfortable and fit securely--we just wish there were more in the package, as they get worn and dirty quickly.
Along with the ear fittings, you'll find two other accessories in the Westone UM2's box: a cleaning pick and a semihard case. The latter is quite nice, and it includes a wrist loop and a special netted slot inside for the earpieces. Conspicuously absent are a quarter-inch adapter and a volume attenuator, two add-ons we've come to expect from earbuds in this price range.
The Westone UM2s feature two drivers in each earpiece--one each for low and high frequencies--along with a passive crossover, which passes the signal within the earpieces. This apparently keeps the bulk off the wire but, as we've seen, adds it to the earpieces. Although Westone doesn't advertise the UM2s as noise-isolation earphones, they do an excellent job keeping out ambient noise; in fact, closer study of the specs reveals that the 'buds are capable of providing up to 25dB of noise reduction. What all this--along with a sensitivity of 119dB per milliwatt and an impedance of 27ohms--adds up to is stellar audio performance.
Using a Creative Zen Micro Photo for reference, we tested the Westone UM2 earphones on a range of music, all of which sounded fantastic. The a cappella at the beginning of Eve's "Be Me" was crystal clear and defined, and when the bass dropped in, we were met with rich, tangible lows--close to what we've experienced with high-end, full-size headphones, though not quite as encompassing. Alice in Chains's mellow rock track, "Rotten Apple," sounded warm and inclusive. But it was a Keoki dance track, "Magic," that really stole the show. Every detail jumped out, and the Westone UM2s opened the sound and delivered the mix of highs and lows exactly the way you'd expect from a set of dual-driver 'buds: beautifully. Overall, when compared directly to Shure's E4cs, we didn't notice a difference.