Kamikaze Ground Crew's setting of Shakespeare's "O Mistress Mine," from their Postcards from the Highwire (AIFF, ripped from the band's Busmeat CD), is a solid delight. Tuba, mandolin, and clarinet carry the melody, while Gina Leishman's relaxed voice convinces you that her offer to "Come and kiss me, sweet and twenty" is sincere. The hf2 captured her husky, 1930s-jazz–tinged voice without stinting on the tuba's bass or the mandolin's space. Sigh. Sweet Will sure could write a hit.

Get it in your head
To paraphrase Clint Eastwood: At some point you've got to be asking yourself, in the hf2, did Etymotic design a more affordable version of the ER-4?

Listening to Bley's Mondsee Variation 1, I was surprised that my ER-4S (recently refurbished by Etymotic to current standards) sounded a tad less bright than the hf2s, while also extracting the slightest bit more microdynamic detail. For example, the ER-4S brought to my attention some rustling noises during that initial chord's fade to silence. I checked—I could hear it through the hf2, but it was deeper in the acoustic. Is that a good thing? While I want to hear everything on my recordings, I don't generally choose gear by listening for noises.

With "Cussi No' la Cridia," the hf2 was again slightly brighter—and had an ever-so-slightly lighter tonal balance than the ER-4S. The latter got the tuba righter, not to mention the blend of the bass, which was integrated better into the total mix.

The differences were similar with "I'll Fly Away." Randolph's and Dickinson's guitars had a bit more bite through the hf2 (Cody Dickinson's cymbals, too), which I enjoyed. The slight bass boost through the ER-4S gave the track more drive, however. Score it a tie on points, despite the differences being audible. I heard deeper into the soundstage of "O Mistress Mine" with the ER-4S, although Leishman was slightly farther out front with the hf2. Again, the differences were audible but slight, more matters of preference than of "accuracy," I suspect.

My suspicion is that the ER-4S has perhaps 2dB more bass boost than the hf2, while the hf2 drops off at a slower angle above 10kHz. Which was better? Obviously, I was surprised in the head-to-head comparison by how well the ER-4S came off 15 years on. Everything I liked about them then I still respect and respond to. The reverse is also true: I found the ER-4S's stiff, microphonic cable a major pain in the tucchus, and greatly preferred the hf2 for daily use, working out, even walking around. I also really appreciated its click-to-pause control, and, if far more incidentally, its microphone.

'Cause two heads are better than one
Is comparing the hf2/hf5 to the more expensive ER-4S fair? I think so because the 4S was Killion's design target. However, I also compared the hf2 with the $1100 Ultimate Ears UE-10 Pro (which has custom molded hard earpieces) and the $500 Shure SE530, which joined the ER4S as one of my references after I reviewed it in December 2007.

Because of the UE-10 Pro's molded earpiece, it does achieve a very tight fit, but it also feels bigger and heavier—which is weird in a component that weighs 2oz at most. The '10 had deeper bass than the hf2, but was similar to the Etymotic in top-end extension. Despite the added low frequencies, the UE-10 did not sound darker than the hf2s—nor did the hf2 sound bright.

With the Shure, it was more of a toss-up, not least because of the difficulties in matching levels. With levels matched to the extent I could, the differences were not profound. However, while the hf2 had bass impact equivalent to the three-armature Shure, it had a lighter timbre in the high midrange and upper frequencies. I didn't find that extra presence a liability; instead, I thought that it enhanced the hf2s' soundstaging—if that term can be used with headphones. What I heard in "Cuissi No' la Cridia," for example, was more ambience and greater separation of the individual instrumental voices.

The Etymotics, it turns out, can hang with a pretty tough crowd.

Heads up!
Of course, the hf2 and hf5 have another arrow in their quivers: They're stone values at $179 and $149, respectively. I have in-ear headphones whose ear-mold castings alone cost more.

Combine that price advantage with the level of performance shared by these two models, and the issue of value becomes very persuasive. I have heard no other in-ear headphones that remotely approach the cost of the hf2 or hf5 while offering better performance—the hf2 in particular is the headphone to beat, and the one I'm going to reach for every day. And I know what I'm getting all my close friends for their birthdays. Way to go, Etymotic.