ER4XR Earphones

ER4XR Extended Response $419.93


  • Highlights
  • Features
  • Specifications
  • Available options
  • What’s in the Box?
  • Reviews
  • Replacement parts

ER4XR is Etymotic’s in-ear monitor for those who demand nothing less than the highest reproduction accuracy in the midrange and treble frequencies, but prefer a tastefully added bass presence.

The ER4XR right and left channels are matched within an industry-leading 1dB across frequencies from 100 Hz to 10 kHz.

The ER4XR is a must-have for audiophiles and consumers, looking for very accurate in-ear monitors with a taste of added bass, for a more “fun” sound signature.


ER4XR is the highest-performing single driver in-ear monitor. The IEM shells are made of anodized aluminum, CNC machined with extremely tight tolerances. Using a single Balanced Armature (BA) driver allows for extremely accurate IEM without the added complexity of crossovers, and helps keep the aluminum body small and slim. The included high-quality user-replaceable cable is reinforced and twisted, to improve longevity and durability.

Etymotic IEMs are world renowned for their class-leading passive isolation, providing 35-42 dB attenuation (depending on ear tips used and the depth of insertion). For comparison, most custom IEMs provide approx. 25-28dB attenuation and foam ear plugs attenuate up to 32 dB.

Which ER4 is right for you?

Both ER4 models, the ER4SR and ER4XR, use the same Balanced Armature (BA) drivers. The only difference is the tuning of the lower (bass) frequencies. The ER4SR, being the “reference” model, is tuned to be as precise and flat as possible. The ER4XR, being the “fun” model, is tuned with added bass. As you can see from the frequency response graphs below, ER4XR adds 1-2dB to the mid-bass frequencies (below 200Hz) and 3-4dB to the lower-bass and sub-bass (below 100Hz). The rest of the frequencies are practically identical.

ER4SR is ideal for sound engineers and mixing technicians who must have a precise and accurate sound reproduction across all frequencies. ER4SR is the IEM of choice for audiophiles and consumers who like to listen to their music exactly the way it was recorded.

ER4XR, with its tastefully added bass, is favored by audiophiles and consumers who prefer a little extra bass presence when enjoying their music. This model is not bass-heavy by any means.

Frequency response graphs and Etymotic’s target

Etymotic’s target frequency response graph represents a “perceptibly flat” frequency response. Our goal is to have a flat frequency response curve when the music notes hit your eardrums. To achieve that, we need to account for the resonance inside the average ear canal, since IEMs bypass the outer ear structure. The result is the need for higher SPL in the 2-5k region (lower treble) for compensating said resonance. That is the reason for the “hump” in that region.

The target curve that Etymotic is using for tuning our IEMs differs slightly from the Harmon preference curve. It was developed in-house more than 20 years ago, leveraging on our human hearing expertise and acoustics research.

Accurate Earphone Reproduction

When tuning in-ear monitors to accurately reproduce a recording of a live performance, our goal is for the sound hitting the eardrums to be identical to that at the original performance. To achieve this, the acoustic properties of the ear must be factored in. The acoustic resonance and horn effects of the ear change a flat audio signal entering the open ear into sound with a (2700 Hz) high-frequency boost, which is the same response heard at the eardrum in a typical ear. That is the reason for the “hump” in the frequency response graph below, which assures the eardrums perceive a perfectly flat frequency response for all frequencies.


Frequency Response

20 Hz – 16 kHz


Single high-performance balanced armature per channel

Noise Isolation

· 35 dB using silicone ear tips

· 42 dB using foam ear tips


45 Ohms @ 1 kHz


98 dB @ 1 kHz, 1 mW

Maximum Output (SPL)

122 dB


Detachable reinforced, twisted 5 ft with MMCX connectors


2 Years

User Replaceable ACCU-Filters


Custom-Fit Option





Extended Response


Extended Response with Etymotion Bluetooth Cable

· In-Ear Monitors

· Detachable 5 ft. cable with 3.5mm gold-plated stereo plug

· Assortment of eartips:

o 4 Dual Flange Silicone Pairs: S, M, L, XL.

o 2 Triple Flange Pairs: Standard and Large.

o 2 Foam Pairs: Standard.

· Replacement Filters to protect the BA drivers from ear wax

· Filter removal tool

· Shirt clip

· Zippered storage case

· Channel-Matching Compliance certificate

C.B. 12/12/2021

Just superb.

I started with Etys around 2000, and quickly got a pair of ER4P's, that are still going strong, with one free repair from Etymotic when the plastic cracked. About a year ago, I decided to upgrade to the ER4XR, and wow I'm glad I did. 30 years of engineering experience really shows. Unsurpassed noise isolation, extremely compact, fabulous sound, just enough extra push on the bass to give a fuller sound. I have recently paired the ER4XR's with a THX Onyx DAC/AMP and a Lavricable silver cable, and the sound is just incredible; likely more than I can justify with my old ears, and certainly as good as I'll ever need. Combined with lossless streaming services, I can't really imagine better sound.

Nick Shortland, Ireland 11/22/2021

Perfectly balanced accurate sound

This was my 3rd set of ER4s. First set was eaten by my dog in 2011. 2nd set was in constant use until 2020 at which point one side wore out. Rather than get them repaired I treated myself to the latest ER4XR set with a generous Etymotic upgrade deal. I am pleased with the overall balanced sound which is perfect, but the extended bass is just what they needed. Not too much bass to disturb the balanced sound, but enough to bring modern music alive. These are still my reference headphones and I would strongly recommend getting custom molds made to ensure that you have a perfect fit. An extra 100 well worth spending.

Mark Kim 07/29/2021

The Relentless Homework of Perfection for 3 decades

Keep in mind that these earphones aren't bass heavy and were strictly meant to provide a flat but full-bodied frequency response that's close to the Harmon preference curve and what each music artists wanted. While the Triple Flange Eartips can be uncomfortable to some, the foam eartips are worth using and when combined with Comply Eartips (or preferably with the Etymotic Custom-Fit Option), the earphones become very comfortable in airline flights. It all boils down to how your ears can get used to the triple flange sleeves and the foam ear sleeves, but in this review, I used the Etymotic Custom Fit Option, which is the best option for people with complex ear canals like myself. Etymotic ER4XR has no artificial highs or lows, only producing frequencies in which the artist intended. While $300 USD may be a little bit steep, it's still worth considering.

Foam Pairs: Standard

Triple Flange Silicone Pairs: Standard and Large

Dual Flange Silicone Pairs: S, M, L, XL

Request a Quote for
ER4XR Earphones

To contact us, please complete the form below and click on "Request Quote".

Required fields are marked with a *

  •  Please check if you would like your name added to our mailing list.