The name "Etymotic" means "true to the ear" and is pronounced "et-im-oh-tik." Mead Killion founded Etymotic Research in 1983 to design products that accurately assess hearing, improve the lives of those with hearing loss, and protect hearing. His first in-ear headphone designs--the ER-1, 2, 3--were used for diagnostic testing and precision auditory research. The company's first noise-isolating in-ear earphone, the ER-4, debuted in 1991. I remember hearing an early ER-4 and it was radically better than any other portable headphone at the time.
The original ER-4P, which was designed for use with portable cassette and CD players, came out in 1994, long before the iPod catapulted the headphone market into the stratosphere. It was priced at $330, making it a very expensive headphone for the time. The current ER-4 models go for a little less, the ER-4PT runs $299, but Etymotic also offers a broad range of less expensive headphones.
ER-4 headphones are still made in Etymotic's Elk Grove Village, Ill., factory, and the left and right drivers are hand-matched to within 1 dB of each other. The headphone comes with a two-year warranty, double the length of most high-end headphones. If an ER-4 is returned for service, factory technicians confirm the left and right channels still match within the original tolerances before the unit is returned to its owner. Also noteworthy: each ER-4PT is shipped with a "channel-matching compliance graph," signed by the Etymotic engineer who precision matched and custom tuned the balanced-armature drivers.
The ER-4PT is very similar to the ER-4P, but the new model comes with extra mobile adapters, a large plastic storage case, a small travel pouch, and accessories for travelers. The braided cable and earpieces look slightly different than my old ER-4P. I have unusually shaped ear canals and don't always have the easiest time getting a good, air-tight fit with many in-ear headphones, but Etymotic's Triple Flange ear tips work like a charm. True, they must be deeply inserted into my ear canals, but they never accidentally fall out.
I started this review by comparing the ER-4PT with($149) in-ear headphones. They share a family resemblance sonically, but the ER-4PT has a more refined sound. It's not only richer in balance, but the soundstage has more depth and space. The HF5 pushes the instruments and vocalists closer in, so you miss the sense of musicians playing in a room or concert hall. For the price, the HF5 is still very good, but the differences between the two headphones are the sorts of things that audiophiles appreciate.
The ER-4PT is no bass champ, so it has significantly less low-end brawn than Monster's Turbine Pro Gold ($299) in-ear headphones. The Turbine Pro Gold adds weight and punch to the bass, but it softens detail compared with what I heard from the ER-4PT, which definitely sounds more accurate. Then again, if you really like bass, go for the Turbine; if you prefer maximum clarity, get the ER-4PT.
The ER-4PT's key strength is its neutrality; it's a very high-resolution device. Play well-recorded music and you will hear more of the subtle stuff--the breath of a singer, the brush of the guitarist's fingers against the strings, the rattle of a snare drum--than you will with other headphones. The ER-4PT's excellent noise isolation plays a role here; you'll hear more-quiet details in the music when they're not masked by external noise.
To finish up I compared the ER-4PT with my 10-year-old ER-4P. I expected the two to be very close, but the older headphone was slightly more "relaxed" and more laid-back in its tonal balance. Which brings up the matter of headphone life expectancy. If Etymotics are treated with care, they should last 10 years. I used the ER-4P as my daily headphone for many of the last 10 years, and never had a problem with it. How many $50 headphones will you buy over the next 10 years?