Ultimate Ears, the audio arm of Logitech, makes in-ear monitors for a wide range of musicians, from Metallica to Sheryl Crow. The super.fi line is Ultimate Ears' consumer angle, and the super.fi 5 is one of eight noise-isolating models currently available. The big claim on Ultimate Ears' website is 26db of noise reduction in optimal conditions. On the New York City subway, these headphones did a terrific job of shutting out the sounds of a speeding train. They were similarly good filtering basic office noise. That said, the 5's largest earbud option was not big enough to fill my (apparently abnormally spacious) ear canal, so I had more moderate results on my proving grounds--my bike commute to work, where I pass traffic, construction sites, and a helipad. Random loud noises were less isolated than continuous sound. Having been recently spoiled by the clarity of the Etymotic hf2, I compared the super.fi 5s to them side by side. Ultimate Ears does a much better job with rock 'n roll--they're significantly louder than the hf2, and handle bass with much more oomph. But they're muddier than the Etymotics: more like satellite radio and less like a digitally remastered CD. They left me wondering whether the engineering in other Ultimate Ears models, like the super.fi 5pro or the top-line 700 model, would be more satisfying and pro-quality. Of course, purity isn't everything, and the super.fi 5s are decidedly peppier headphones. I find it hard to fall into a state of audiophile bliss with them, but I can have fun with them, and thanks to the good isolation I can do so without blowing out my ears. I can see why Kirk Hammett would approve. Ultimate Ears super.fi 5 headphones ship with a generous set of five silicone and foam cushion options. There's a cleaning tool--which is clever, although I'm not sure what to do with it--and a delightfully compact hard plastic case.