July 2011

Etymotic Research hf5I do most of my headphone listening at home using a dedicated headphone amplifier and full-sized cans, but when I’m listening on the go or at work I prefer in-ear monitors (IEMs) -- a type of earphone that is inserted into the ear canal. Not only do their small sizes make IEMs more convenient than regular headphones, but I appreciate the level of isolation that most of them provide. I also like the fact that IEMs can be adequately driven directly from the output of an iPod or other portable device. 

When, 20 years ago, Etymotic Research released their first high-fidelity in-ear transducer for music reproduction, they virtually created a new product category, and that design, the ER-4, is still their top model. The subject of this review, the hf5 ($149 USD), is an attempt to provide most of the performance of the more expensive ER-4 at a price that appeals to a larger number of consumers. The savings are realized by manufacturing the earphones as a complete unit in China rather than hand-matching each driver at Etymotic’s headquarters, in Illinois. 

Although they cost less than the ER-4s, the hf5s come with a full complement of accessories, including a carrying pouch, replacement filters, a filter-changing tool, and a selection of eartips. Choosing the appropriate tips to use is a matter of both comfort and sound quality. The three-flange silicone tips provide the best isolation and bass response, but must be inserted deep into the ear canal. Once I had them properly inserted, I found them extremely comfortable, but some people just don’t like sticking things that deeply into their ears. The foam tips, particularly the rounded ones, were also very comfortable, sounded nearly as good, and didn’t have to be inserted as far. Either way, I could use the hf5s for hours with no discomfort, and almost forget I was wearing them at all. 

The hf5s’ 4’-long cord is terminated in a 1/8” straight stereo plug that’s appropriate for use with essentially all portable devices that can ride on a belt clip or in a convenient pocket. The cable is soft enough to not be microphonic, and a clip that can be attached to the collar further helps in eliminating rubbing, and prevents stress being put on the ears should the cord happen to catch on something. 

I divided my listening time between using the hf5s with my usual headphone setup -- a Grace Design m902 headphone amplifier with a variety of high-quality sources -- and listening to it being fed directly from the headphone output of my fifth-generation Apple iPod containing exclusively lossless files. As expected, either device could adequately drive the hf5s even at very high volume levels. Due to the sensitive nature of IEMs and the fact that their diaphragms are within millimeters of the eardrum, a low level of hiss was always apparent with the iPod, and, at a lower level, even with the Grace. In neither case did I find the hiss distracting, and in no way should this be considered a criticism of the hf5s. 

Etymotic Research hf5Sound 

I’ve heard enough loudspeakers, and then been able to compare what I heard with measurements taken of them, to be able to recognize when a speaker exhibits flat frequency response. I’ve also heard enough headphones, and compared that experience with their measurements, to know that a headphone that sounds flat probably doesn’t measure that way. So when I talk about the hf5s’ frequency response, I’m talking about how they sounded, not how they may or may not measure. The hf5s did not sound flat; rather, their output has been carefully tailored to provide a certain listening experience. 

The very lowest bass was completely nonexistent, even when a proper ear-canal seal had been achieved. Of course, I haven’t heard truly low bass from any earphone -- or most full-size headphones, for that matter -- so I wasn’t really expecting any. The midbass was still a little low in level. The lower midrange was quite well in line with the midbass, but the level started to rise in the upper midrange and into the presence region. Things seemed to fall off in the upper treble, and the top half octave or so was completely absent. One of the things that told me that this frequency contour is by design, not by accident, is that within those ranges, everything seemed very smooth. 

How did all of that translate into the sound of music? Bass instruments were a little light and lacked impact, but bass lines were rhythmically clean and easy to follow. Male voices, especially baritones and basses, tended to sound a bit thinner than is strictly accurate, but not excessively so. Female voices, on the other hand, were very well balanced, with an exceptional level of purity. Instrumental timbres were more believable than through many other earphones, but lacked the full texture that can be heard through designs with better high-frequency extension. The advantage of the hf5s’ shelved-down top octave was that overly bright recordings (of which there are many) and bright-sounding portable players (similarly numerous) did not induce listening fatigue. That’s particularly important when there’s nothing between driver and eardrum to absorb any of that energy. For a pleasurable listening experience with the widest variety of recordings and equipment, a somewhat rolled-off top octave is a good design decision. 

Lest you think that the reduction in top-octave energy made the hf5s sound dull, that character is primarily determined by frequencies lower down. The hf5s were actually a little on the bright side of neutral. The word bright has negative connotations in audio reviewing, but I don’t mean it in that sense. The hf5s did not sound harsh, aggressive, or annoying. Their somewhat bright overall tonal balance brought voices and instruments in the vocal range forward in the mix, and concentrated my attention on the melodic line. It also made lyrics remarkably intelligible. (Perhaps that harks back to Etymotic’s extensive experience in the development of hearing aids.) Such a balance does, however, serve some types of music better than others. Unsurprisingly, vocal-centric pop and rock recordings greatly benefited -- the sounds of guitars, too, are centered in the vocal range -- but large-scale orchestral music fared less well. It’s not that I couldn’t have an enjoyable experience listening to classical music through the hf5s, but the balance of the orchestra was shifted relative to how it’s heard in the concert hall or through other equipment. 

Etymotic’s website states that the isolation offered by their earphones is the best in the industry, at up to 42dB, though I have no way of verifying that claim. With the three-flange silicone eartips, the level of isolation was astounding, but no more so than with other earphones that use the same type of tips. Whether or not it’s better than that of the hf5s’ competitors, such a high degree of isolation has a number of benefits. Without having to compete with outside noise, volume levels can be kept low, which is better for your hearing over the long term. That’s important in the loud listening environments in which people often listen to portable sound systems. It’s also good in the workplace, so that your coworkers don’t distract you from your music -- I mean, your productive work activities. When considering the noisiest environments, the combination of excellent isolation with the hf5s’ prominent upper midrange should let you follow the music without having to listen at a dangerously high volume. The exclusion of outside sounds also means that small details in the recordings become very apparent. If you like to hear the rustle of a turned page or the smallest intake of a singer’s breath, then the hf5s will not disappoint. 


I haven’t heard Etymotic’s ER-4, and it’s been too long since I heard the ER-6 for me to make a valid comparison of the hf5 with that model, but I do own Shure’s E3c ($179 when available). The E3c is now a few generations old, and shouldn’t be taken as being representative of Shure’s current offerings, but it did sell pretty well when available, and still provides a relevant point of reference. 

The E3c earphones came with an extensive collection of eartips, among them three-flange silicone tips similar to those included with the hf5s. I found them to provide the same level of comfort and isolation. The sound of these earphones, on the other hand, could hardly be more different. The Shures have a much richer midbass than did the hf5s, and their response is flatter up into the upper midrange. After that, the response of the Shures seems to fall off a cliff -- I don’t hear much of anything above 6kHz or so. The overall sonic signature of the E3c earphones is reminiscent of that of an old console radio: They’re never fatiguing, but they’re far from accurate. Voices and instruments sound as if they’re coming from farther away than with the hf5s. For some types of music -- large orchestral works -- that may be a better perspective, but it obscures many details. That faraway perspective and consequent suppression of detail tempt one to turn up the volume, which can be damaging to the hearing over the long term if one isn’t careful. While some listeners may conceivably prefer the sound of the Shures, the Etymotics are unquestionably the higher-fidelity design. 


The Etymotic Research hf5 is a cannily voiced design from a company with a thorough technical understanding of human hearing. These earphones are not strictly accurate, but they provide a thoroughly enjoyable listening experience with a high degree of detail. Their frequency balance, combined with their excellent isolation, make the hf5s ideal for listening to portable devices in noisy environments. In such environments, and with the limitations of portable players, it’s hard to justify the need for going beyond this already high level of performance. At only $149, the Etymotic hf5s offer a solid value. 

. . . S. Andrea Sundaram

Associated Equipment 

  • Headphone amplifier -- Grace Design m902
  • Headphones -- Ultrasone Pro 2900, Shure E3c
  • Digital sources -- Ayre Acoustics C-5xeMP CD player, Apple iPod (fifth generation)
  • Computer -- Laptop running Windows Vista and Realtek HD Audio ALC 272, with coaxial digital output running foobar2000
  • Analog source -- Michell Tecnodec with HR power supply, modified Rega RB-300 tonearm, Shure V15X cartridge, Trigon Audio Vanguard II phono stage with Volcano PS power supply
  • Interconnects -- DH Labs Revelation, QED Silver Spiral, JPS Superconductor
  • Power conditioner -- Equi=Tech Son of Q

Etymotic Research hf5 Earphones
Price: $149 USD.
Warranty: Two years parts and labor. 

Etymotic Research, Inc.
61 Martin Lane
Elk Grove Village, IL 60007
Phone: (847) 228-0006
Fax: (847) 228-6836 

E-mail: customer-service@etymotic.com
Website: www.etymotic.com