The balanced armature vs. dynamic driver debate stretches back as far as Coke vs. Pepsi, Ford vs. Chevy, and Bad Boy vs. Death Row. Those who swear by balanced armatures cite the twitch-quick response and accurate sound reproduction as advantages, while driver fanatics deride the lack of bass and warmth. The new Ultimate Ears 600 noise-isolating headphones purport to employ armature technology similar to that of their Custom In-Ear Monitors. So let's see if UE's professional expertise has trickled down into their more affordable products.
As an inherent design quality, balanced armatures are generally weaker at frequency extremes, and the 600s are no exception. While the midrange (80-12000 Hz) is clear and balanced, notes either very low or very high are very quiet. The top end is no big deal, since little—if any—music goes beyond that threshold, but I know that many customers may be put off by the lack of heavy, thumping bass. "What is the point," you may ask, "of dropping nearly $100 on a set of headphones that won't rattle my skull when I listen to Usher's Hey Daddy at full blast?"
Well, if what you want is a 10" subwoofer surgically mounted in the back of your head, then no, there's no point in getting the 600s. But if you're looking for something a bit more detailed, a bit more nuanced, and a lot more sophisticated, read on, because Ultimate Ears has a product genuinely worthy of your consideration.
Musicians and sound engineers know that the most accurate reproduction of sound is not necessarily the one that sounds the best for daily listening. In order to properly hear a blend of vocals and instrumentation for purposes of mixing or editing, headphones need to deliver punchy and articulate sound. The 600s deliver on both counts, sounding rather bright and trading smooth, comforting warmth in favor of an all-exposing cool sound. As a musician, I'd be afraid of hearing a recording of myself through the 600s. They are absolutely merciless. No error or fault, no matter how minute, is hidden. If I were editing, however, that clarity and intelligibility would be an absolute dream.
The 600's home turf is classical music. No sub-$100, general-consumer headphones I have heard can match the 600s in delivering the multi-layered complexities and nuances of Tchaikovsky or Mozart. The third movement of Beethoven's Moonlight Sonata—characterized by blisteringly fast arpeggios—sounds excellent, the armatures' lightning-quick response delivers each note with precision and clarity. Staccato notes and silences do not intrude into each other's respective time, especially impressive when you consider how many individual lines are going on at the same time in an 80-piece orchestra. The 600's neutrality is a welcome feature in this genre, because it maintains balance between the instrumental sections. Rock also sounds excellent, especially the less-distorted, less-bass-reliant sounds of the '70s and '80s. The 600s reproduce vocals very well, giving a lifelike, human quality to recordings. Note, however, that lower-quality compressed music will actually sound worse on the 600s, as the flaws that would have otherwise been hidden by lesser headphones are just as clear as everything else.
Ultimate Ears states that the 600s offer 26dB of noise reduction, but from my experience that varies by frequency. I've noticed that midrange noise—people talking, shouting, etc—is drowned out very well, but the low rumble of a bus is hardly affected. Also, I wasn't a big fan of the cable itself: it transmitted a lot of movement noise, and it terminated in a straight connector rather than an angled one. I know it's a minor complaint, but straight connectors are much more prone to stress-induced fraying; I personally would have preferred if Ultimate Ears used a 90° connector like they do on the lower-end 500 and 350.
Included with the 600s are five different sizes of rubber ear tips as well as two sets of ComplyTM foam tips. The foam tips offer much better isolation and seal, and with them in the 600s sound better as well. Also, Ultimate Ears has included a hard carrying case, which stores the headphones and ear tips easily.
In my opinion, the 600s are great for listening to music from a critical perspective, as they expose every line and note, but on a day-to-day basis I'll stick with a set of warm, mellow dynamic drivers. They should be marketed, I think, more as a sort of introductory-level "My First IEM" than the top-of-the-line general-listening headphones that Ultimate Ears says they are. Customers who can really appreciate the crystal-clear instrumentation and the quickness of the armatures are probably looking at other IEMs, and the 600s provide a comparatively cheap alternative.
Impedance: 13 Ohms, 1kHz
Sensitivity: 115 dB SPL/mW, 1kHz
Speaker type: Single driver, proprietary, balanced, top-fire armature
Weight: 0.44 ounces (12.4 grams)
Noise isolation: 26 dB
Input connector: 1/8 inch (3.5 mm)