25 Years of Making a Good Thing Better: The Etymotic ER4sr and ER4XR

It must have been around 1992 while manning the phone in the early years at HeadRoom that I got an excited call:

"Dude, I just got off an airplane with this guy who had these cool insert headphones. He's a location sound recordist for movies and uses them for their isolation and good sound. I gave them a try...I need a pair badly! Do you know where I can get some Etymotic ER4 earphones?"

It was the first I'd heard of such a thing...or most anybody for that matter. With Etymotic's 1991 release of the ER4S and ER4B, the world received its first commercially available universal fit in-ear monitor. The history of the product goes even farther back to the ER-1, ER-2, and ER-3; the first insert earphones for research and audiology.


The first ER series in-ear monitors for research and audiology had drivers in a separate unit with the sound traveling up narrow tubes to the earpiece.

Etymotic is, and always has been, primarily a hearing health equipment producer making a variety of devices used in research, audiology, and personal hearing safety. The fact that they make excellent IEMs for consumers seems to me more a byproduct of their expertise in the field rather than a strategic goal. They make reference level transducers for the human ear...why not put a 3.5mm plug on it and let people plug it into their player? And boy did that work!

As I recall, when HeadRoom was the only on-line retailer for their products we were selling boatloads of ER4S IEMs and it took all of us by surprise. I'd guess it was nearly 25% of our revenue one of those years.

With the rapid consumption of a first of a kind product, we also heard lots and lots of feedback. "How do I put them in my ears?" "I don't hear any bass." "I've got a good seal but they're still too bright." "Hey, I just pulled them out of my ears and now I've got a tip stuck in my left ear!" "My stem broke." And I kid you not: "My Pomeranian ate a bag of those yellow foam tips from my husband's IEMs and Pookie is in surgery now. WHY THE HELL DID'T YOU PUT A DANGER WARNING ON THE BAG FOR DOGS!" (Um...can your dog read?)

Over the years Etymotic has evolved the ER4 in numerous ways. A variety of tips have evolved and Etymotic is generous in providing users with a numerous options for a personalized fit. Housing material and integrity has been improved for better durability. The tuning has change over the years, generally with a warming trend through the models. (More on this later.) As a result, Etymotic now has an entire line of IEMs that descend directly from the original ER4 to serve the needs of a variety of consumers from kids to smartphone users, and for those on a budget to audio pros and audiophiles.


Etymotic ER4SR and ER4XR ($349)
These new Etymotic IEMs show ample evidence of their 30 year evolution. The value proposition is extraordinary here; these new IEMs pack in a lot of performance at this price.

These are single balanced armature receiver IEMs with a deep insertion fit. The body and stem are now anodized aluminum for improved durability. Tips fit over the stem very securely. Filters are fitted into the end of the stem, and spare filters and removal tool are supplied.

The cable is just shy of five feet overall with 14" of Y-split. The main cable has a very nice feel to it, quite dead feeling and lays flat nicely without tangling. The Y-cords are thin twisted pairs and lay down around the ears easily. The adjustment slider moves smoothly on the cables and is appropriately secure once set. The Y-split is accomplished with a vary nice anodized aluminum cylinder. The cable is terminated at the player end with a rubber molded near-90 degree angle 3.5mm TRS plug. Plug body is narrow near the connector allowing it to fit through smartphone cases. Ear piece cable ends are terminated in an angled MMCX connector with rotational position detent. A shirt clip is provided.

I find this an excellent cable that easily takes a proper position and feels comfortable when worn up and around the ears. My only comment is that it would be nice if Etymotic offered a version of the cable with a remote/mic on it for headset use.

Accessorization for these is simply outstanding. The IEMs come with a fairly large, hard-sided, clamshell case. Also included is: an assortment of tips; 3.5mm to 1/4" adapter; filter removal tool and replacement filters; and a shirt clip.

My only comment here is that the case is fairly large and likely too bulky for every day use. It would have been nice if they included one with purchase, but Etymotic does make a small zipper pouch for $4 that would be handy for every day carry of the IEMs alone.

Comfort has always been an issue with Etymotic's deep-insertion IEMs. It's not their fault really, it's the nature of the beast. Deep-insertion IEMs seal the entire front half of the ear canal, ideally to the bony section of the ear canal. There, the skin of the ear canal grows directly on bone. Sealing the IEM there does a couple of good things:

When an IEM seals at the entry of the ear canal, it creates a volume of trapped air between the entrance and ear drum. Because the first half of the ear canal is fleshy it can vibrate with mechanical input—like with foot-falls or chewing on something crunchy. As the ear canal vibrates it slightly changes shape, and with changing shape its volume changes slightly, which causes the ear drum to move in and out to compensate for the changes in air pressure with volume change. This is called the occlusion effect, and it is why you hear your voice louder when you plug up your ears.

With a deep insertion earphone having a tip that seals at the bony section, you don't have as much change in ear canal shape with vibration resulting in a significant decrease to the occlusion effect. With an Etymotic earphone properly inserted you get less noise from your heart beat, breathing, foot-fall, or your own singing along...if you're into that sort of thing.

It also improves isolation from outside noise. Related to the occlusion effect above, when you plug the outside entrance of your ear canal outside sound will still vibrate the flesh around the ear. This vibration will be coupled to the ear drum through the occlusion effect. With a deep-insertion earphone sealed at the bony section, isolation from outside noise is essentially at it's maximum possible. There does remain some sound that gets to the ear through bone conduction, but there's nothing you can do about that short of clamping your skull in a vice.

Bottom line: With Etymotic deep insertion IEMs you get the lowest noise floor and highest isolation possible.

The down side is sticking something that far into your ear can be quite uncomfortable. Fortunately, Etymotic has over the course of the last 20 years developed numerous tips; spend some time trying them all out and you'll almost certainly find one that's reasonably comfortable. The best solution, however, is to get some Custom Fit Earmolds, which provide a significantly more comfortable fit than generic tips.

User Notes
Couple quick random but worthy notes:

  • The earpiece dimensions have not changed and custom tips made for any of the previous ER4 series will fit the ER4SR and ER4XR.
  • If you own a pair of ER4B, ER4PT or ER4S IEMs, you can upgrade to one of the new models. Price is $225 or $275 depending on whether your pair is within the 2-year warranty period and whether you have proof of purchase. Details here.

Alrightythen, let's turn the page and talk about sound quality.

Etymotic Research, Inc.
61 Martin Lane
Elk Grove Village, IL 60007

Inks's picture

Definitely portrayed the flaws well. Still missing some bass and plenty of soundstage. I also wish it was more sensitive for portable players. i also think etymotic has to move on to dynamic drivers to improve the distortion and increase bandwidth.

On a random side note, any chance you can get your hands on the Powerbeats 3? Boy do these sound amazing which totally threw me off guard considering the PB2 were bad. So far it's my reference for imaging and soundstage on a iem and tonal balance is good, bass is cleaner than my JVC FX850s

ednaz's picture

My first IEMs were Etys, purchased from HeadRoom. I'd seen someone wearing them on a flight to Hong Kong while I was sporting my enormous (and awful sounding) Sony NRs of the long ago era. We talked a bit, he told me to go to HeadRoom, and that began a long relationship with several sets of Etys.

After a year, I got the custom tips made. (My ear canal is tall and narrow, and with stock tips, I have to choose between comfort and poor isolation, or great isolation and a wearing time of about an hour.) When I got the custom tips, what hit me even more than the comfort was the sound improvement. I recommend custom tips for them to anyone. So far, everyone who's gone to custom tips has come to the same conclusion, that they make a good IEM a REALLY good IEM. The tips from ACS go in a bit farther than the stock tips do. Despite having a few nice CIEMs, there are days when what I want is the Ety sound, and they are my go-to IEMs for using loud yard equipment, the custom silicone tips are every bit as isolating as the stock tips.

Their dynamic driver IEMs never really appealed to me, and the tips are a different size that's not compatible with my ER4 tips.

So... are the tips on these like the ER4 of the past? That would be great. I have a few sets of tips - one full concha, two the smaller type, and at the moment one set's not in use. Might be something I put on my birthday gift list...

tony's picture

That, right there, is just about the best thing anyone could say about anything. ( one hears soooooooo much sizzle now-a-days )

I went around my house looking for things that I could recommend using your phrase, I found a few easy ones, like our standard issue Maytag Laundry machines but Maytag is sort of a known given. My vast array of work tools has a standout: the little Festool CSX drill gun system ( about $300 ) is superb, far more useful than any of the Cordless guns I've owned or purchased ( during my 4 years as purchasing agent for GM ). I still own 5 Drill guns and a variable speed drill press. The little Festool is the best and most used tool I own ( I could use a 2nd. CSX and am considering buying another ).

My wife would say that her KIA Soul is a "really nice piece of gear" ( she could have any GM product ) she loves her Soul!

"Really nice piece of gear" is now my 5 Star, A+ Rating.

Thank you for the perspective.

I agree, the Etys are really nice pieces of gear ( I travel with two sets ).

Tony in Michigan

ps. I would't have known about Etys if it wasn't for IF!

Akmax57's picture

I bought a pair of the Etymotics in the mid-ninties. I think it was from Headroom. They sounded great and lasted about 15 years before one of the cables broke and I lost a channel. I remember reading they were the result of audiologists working with the hard of hearing. Only two things I didn't like - they were really not very comfortable, and the microphonics were horrible. No cable noise as long as I didn't move, but if the cable moved against my shirt, it was very noticeable. I'd have worn them a lot more if not for those two things. Still, great to see they are among the best sounding out there for what you pay.

Augustus's picture

Hey Tyll, when will we see the iSine review?

ashutoshp's picture

I own a pair of the HF5s and love them to bits. I plan to purchase the ER4s but was unsure about getting custom-fit ear molds because I worry about safety while walking, specifically, in terms of awareness of my surroundings. Is that something worth considering? Thanks.

GNagus's picture

Is it an average of the isolation at certain frequencies? Part of the reason i ask is the isolation plot for these headphones which arrives at -39dB doesn't seem so different than the plot for the Bose QC 35 at -28dB

Dan Wiggins's picture

NRR is calculated as the average attenuation at octave spacings from 125 Hz to 8 kHz, minus 2 times the standard deviation at those frequencies for a sample size of at least 10 pieces.

Basically: sum of (atten@freq - 2 * Sd @ freq)

Note that a loose tolerance (high Sd) will hurt your NRR, and that having strong attenuation at 8 kHz counts as much for attenuation at 1 kHz, even though your noise sensitivity at 1 kHz is 10+ dB stronger than at 8 kHz (meaning you can hear things that are 10 dB quieter at 1 kHz when compared to the same thing at 8 kHz).

NRR is pretty bogus as a number; you could actually build an earplug that AMPLIFIES the 1 and 2 kHz bands and still have a > 30 NRR rating. Much better to go with EN 352 and simply list the average attenuation at each of the frequency bands (125/250/500/1K/2K/4K/8K). I'm not that concerned with great isolation at 125 Hz, but at 1 kHz I'd like a solid 30+ dB of attenuation, please!

pbarach's picture

I bought a pair of Etymotics years ago from HeadRoom. None of the supplied tips were comfortable for more than 10 minutes (narrow ear canals!), and the microphonic noise from the cable made it intolerable to use these on the move. So I returned them and exchanged them for Yuin earbuds, which are perfectly adequate for walking, and I later bought some Bose Quiet Comfort phones for use on airplanes.

monetschemist's picture

I love my ER4s except that I just can't keep them in for more than about an hour or maybe two at the outside. My ears get really itchy... I think the gray (large) silicone tips are a smidgen too big and the clear (medium) ones are way too small to seal, which could be the problem. But yes, they sound great!

Mark Cherrington's picture

I've been using ER4Ps the past few years, and absolutely love them. I recognize that some people prefer more bass, but I've never felt the slightest issue there. To me, these phones sound like music, including the low frequencies. When I listen to other headphones, even very expensive, highly regarded ones, they sound overloaded with bass, and it obscures the nuances of the music. The Etymotics let every whisker of sound come through with perfect clarity, and for me that's the most important thing.

SashaRomero's picture

Dr. Mead Killion's Etymotic organization and headphone.com share an upbeat history about-facing right around 25 years. Starting with the primary audiophile in-ear earphone ever discharged,But now a day a lot more products are available in market online in cheap rate good quality like product available at https://www.linkedin.com/pulse/top-8-best-laser-christmas-lights-star-sh.... Well about the first Etymotic ER-4 show in 1991, the bleeding edge nerds here at headphone.com were among the first to perceive and offer Etymotic Research items to armies of music fans frantically looking for better solid from early cell phones like the great iPod, compact CD players and, yes, the Sony WalkMan tape machine, the top earphone wellspring of loco roller disco artists all over the place. Concocted clamor segregating, in-ear headphones. The ER Micro Pro arrangement headphones were the principal headphones popularized utilizing adjusted armature innovation and are perceived as the world pioneer accordingly precision, to which every single other headphone are thought about. After over 20 years, these reference-quality headphones are still the decision of genuine sound specialists, audiophiles and performers.

halcyon's picture

I'm an ex ER4P/ER4S user. Bought and used two pairs. The sound is an acquired taste, but it does what it does really well.

But to release in 2016 a set of IEMs for _mobile use_ with no option for an inline microphone?

Etymotic, get with the program!

Almost everybody hooks up their IEMs at least part of the time to their mobile phone. They don't want to take off deep inserting IEMs to talk or to talk to the phone. They just want to use and enjoy them.

And Etymotic has inline mics in their cheaper line.

What gives`?

So, I don't buy ER-4XR although I'd like to, because they don't have an inline mic.

2manyheadphones4me's picture

The difference in ear-tip length between the small frost and the large clear ones seem to make a difference in extension above 10kHz.
Measured with Dayton iMM-6 with PVC tube (1 inch, 8mm diameter).

large triple flange: http://imgur.com/a/LCFDg

small triple flange: http://imgur.com/a/yOKSn

Tyll, did you notice this while reviewing? If you haven't tested it, can you measure both the ear tips?

Fractal's picture

Hey Tyll, I really think you will like these earphones. I know you arent a big fan of Bose's none ANC headphones, but man, give these a shot. They might shock you :)