Optoma's NuForce earphone lineup offers solid options for the serious music lover on a reasonable budget. The $199 NuForce HEM2 is an in-canal pair with excellent audio performance geared toward those who want sound approaching flat response, but without sacrificing bass completely. The balance of the audio here is wonderful, though the earphones aren't completely flawless—super-high volumes can cause distortion. However, we won't fret about that too much, considering no one should really be listening to audio at the levels where distortion exists. At normal volumes, the HEM2 delivers a clean, balanced audio experience, and ships with a wide assortment of accessories that puts many competing earphone models to shame.

Design
The red earpieces for the HEM2 have a metallic, almost two-tone sheen. An abundance of eartip options ensures you'll find a comfortable, secure fit. Inside each earpiece, a single full-range balanced armature driver delivers the audio, for which Optoma estimates a frequency range of 20Hz-40kHz.

Not many earphones come with as many accessories as the HEM2. There's a heavy-duty hard shell carrying case, a smaller zip-up case that fits inside it, a molded holder for the two removable earpieces, two cables (one braided with no remote, one regular cable with an inline single-button remote and mic), six pairs of silicone eartips, two pairs of Comply foam eartips, a 0.25-inch stereo jack adapter, and a cleaning tool for the earpieces. 

Performance
On tracks with powerful sub-bass content, like The Knife's "Silent Shout," the HEM2 delivers excellent low frequency response at moderate-to-higher volumes. There's a great sense of body and depth without things ever sounding too boosted or losing definition. However, at top, unsafe listening levels, the HEM2 will distort on tracks with bass this powerful. This isn't a deal breaker since you'd be unwise to listen to tracks at volumes that high, but it is a bit unfortunate that the earphones distort at all—several pairs that cost far less can handle the deep bass here without issue. Regardless, the bass sounds fantastic at normal listening levels, so this is a minor gripe.

Bill Callahan's "Drover," a track with little in the way of deep bass content, gives us a better idea of the HEM2's overall sound signature. The drums on this track can often sound wildly unnatural on heavily bass-boosted earphones, but through the HEM2, the drums receive a very subtle, natural boosting that gives them some extra body and presence without ever sounding too thunderous. Callahan's baritone vocals are delivered with the ideal level of low-mid presence and high-mid treble edge. The guitar strums also receive a bright, crisp presence in the higher frequencies, and the entire mix has a lovely balance throughout—no one range stands out too much, and things are never too bass heavy nor too bright or sibilant.

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On Jay-Z and Kanye West's "No Church in the Wild," the kick drum loop gets a strong enough high-mid presence to allow its sharp attack to slice through the layers of the beat, while its sustain has a more modest low-mid thump to it. The result is something close to what I imagine the mix engineer was going for on this track—the loop sounds powerful without occupying the entire bass range, allowing the sub-bass synth hits that punctuate the beat to stand out. Through the HEM2, the sub-bass is powerful, but not overwhelmingly boosted. The vocals from all three performers on this track are clear and bright without ever sounding sibilant—they float over the mix cleanly.

When listening to orchestral tracks, like the opening scene in John Adams' The Gospel According to the Other Mary, the higher register strings, brass, and vocals own the spotlight, as usual—the sound here veers more toward the higher frequency end of the balance beam. The lower register instrumentation on this track doesn't quite get the subtle boosting we are sometimes hoping for in order for things to sound a bit fuller and vibrant, but in no way does the resulting sound feel thin or tinny. This is a clean, flat response-style sound signature that will appeal to audiophiles but probably leave big bass lovers wanting more low-end.

For $200, the Optoma NuForce HEM2 delivers a compelling audio experience and a boatload of accessories. In this price range, we're also fans of the Klipsch Reference X6i, the Master & Dynamic ME05, the Bowers & Wilkins C5 Series 2, and the RHA T20. Each of these pairs offers a slightly different balances of lows and highs compared with the HEM2, and one is bound to suit your taste.