The Mobile Jamz ship with five pairs of silicone eartips to ensure a good fit in your ears: three sizes of the standard circular tips and two sizes of triple-flange tips. We had trouble dialing in a tight seal on all the included sizes, so Monster sent over a sample back of its SuperTips gel and foam inserts. These are slightly more conical than the standard tips and the foam versions expand for a perfect fit in the ear canal, which made it a lot easier to attain a seal. Your mileage may vary, but we liked the SuperTips much more than the standard pack that came with the Mobile Jamz. Unfortunately, the sample pack will set you back another $25, when they should really just come in the packaging with the headphones.
Once the eartips are inserted properly, you won't be disappointed with the fidelity of the Mobile Jamz. We're just as excited about these as we were about the Turbines, and they performed admirably across a variety of genres. The headphones exposed every instrument beautifully on the Miles Davis Quintet's kaleidoscopic ballad "Something I Dreamed Last Night" without blowing out the horn section, and the breadth of the soundstage is unmistakable, almost like the music is coming from an external source, not just inside your head.
Sound isolation is often a big selling point for shoppers; look no further if you're shopping for a set of in-ear buds to drown out ambient noise on the subway, on the bus, or in the office. The Mobile Jamz do a better job of blocking outside noise than the Klipsch S4i, a similar set of MP3 player-friendly earbuds for $100, and the Jamz's isolation is so deep that it's difficult to notice someone calling your name directly behind you--just a warning to use your eyes to pay attention to your surroundings while using these headphones.
Our final criticism is that you can hear the sound of anything rubbing against the headphone cord inside the headphones while listening to softer music, so, again, the Jamz aren't the ideal candidate for active listening at the gym or while jogging. If that's your main concern, check out this roundup of headphones better suited for exercise.