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Etymotic ER4XR IEM Review

Rate this IEM:

  • 1. Poor (headless panther)

    Votes: 39 24.8%
  • 2. Not terrible (postman panther)

    Votes: 71 45.2%
  • 3. Fine (happy panther)

    Votes: 32 20.4%
  • 4. Great (golfing panther)

    Votes: 15 9.6%

  • Total voters


Staff Member
CFO (Chief Fun Officer)
Feb 13, 2016
Seattle Area
This is a review, listening tests, equalization and detailed measurements of the Etymotic ER4XR IEM. It is on kind loan from a member and costs US $300.

Etymotic ER4XR IEM Review.jpg

Perhaps there is no more famous IEM manufacturer than IEM. I think I got my original Etymotics some 30 years ago. The E4XR has slightly higher bass response than the E4SR which I purchased a few years ago.

Different set of tips are provided. For measurements, I used their conical silicone tips which provided a challenge in getting accurate measurements. For listening, I had to use the foam one as the silicon tips have never fit my ear canal.

If you are not familiar with my IEM/Headphone measurements, I suggest you watch this tutorial:

Etymotic ER4XR Measurements
Let's start with our standard frequency response measurements:
Etymotic ER4XR IEM Frequency Response Measurements.png

As expected, we have flat bass response. Compliance then gets good with some extra lower treble response. For EQ development we have the difference between our measurement and target:
Etymotic ER4XR IEM relative Frequency Response Measurements.png

I was disappointed to see rather high distortion in mid frequencies:
Etymotic ER4XR IEM relative THD Distortion Response Measurements.png

We see a large jump at 114 dBSPL with the graph changing shape, indicating limiting. Seeing how we need to boost bass, that concerns me some.

Another surprise was low sensitivity:
most sensitive IEM measurement review.png

I expect it to need fair bit of power despite rather low impedance:
Etymotic ER4XR IEM Impedance Response Measurements.png

Group delay was uneventful:
Etymotic ER4XR IEM THD Group Delay Response Measurements.png

Etymotic ER4XR Listening Tests and Equalization
First impression was that the sound was "fine." From experience I know that without a comparison reference, these impressions can be faulty so I developed a set of filters one by one:
Etymotic ER4XR IEM Equalization.png

I first dialed in the bass shelving filter. That added warmth to even female vocals where you don't think you need much bass. I then put in a pair of filters to create the flat top EQ we need for that area. This took away some sharpness that was there without it. Filling the hole at 6.1 kHz is tricky as the two channels don't match so I used a conservative value. With all the filters in place, AB testing shows very nice transformation with EQ, with sound being more full bodied and at the same time, with very nice resolution in higher frequencies. My reference tracks sounded fantastic now. Turning off EQ didn't make the experience terrible but for my preference, EQ made a large, positive difference.

I had to have my RME ADI-2 Pro level where I usually have headphones at some -20 dB. Playing sub-bass heavy track as you see in the above display, causes static indicating that I had hit the limit of performance even though the overall volume was not especially high. Turning volume down most eliminated the static but the notes were clearly distorted.

Spatial qualities with EQ were very good for an IEM.

This is a type of iconic IEM you want to have tested. While some of the performance characteristics such as flattish bass was as expected, the high distortion was not. Nor was the slight treble exaggeration. This is an expensive IEM at $300 with an out of box performance that doesn't satisfy in this day and age. With EQ though it does sound excellent.

I can't recommend the Etymotic ER4XR IEM as is. If you have it, I highly suggest equalizing as it nicely improves performance.
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/


  • Etymotic ER4XR.zip
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Here are some thoughts about the EQ.
Please report your findings, positive or negative!

Notes about the EQ design:
  • The average L/R is used to calculate the score.
  • The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
  • A Genetic Algorithm is used to optimize the EQ.
  • The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve (and other constrains) with a fixed complexity.
    This will avoid weird results if one only optimizes for the Score, start your journey here or there.
    There is a presentation by S. Olive here.
    It will probably flatten the Error regression doing so, the tonal balance should be therefore more neutral.
  • The EQs are starting point and may require tuning (certainly at LF and maybe at HF).
  • The range around and above 10kHz is usually not EQed unless smooth enough to do so.
  • I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
  • With some HP/amp combo, the boosts and preamp gain (loss of Dynamic range) need to be carefully considered to avoid issues with, amongst other things, too low a Max SPL or damaging your device. You have beed warned.
  • Not all units of the same product are made equal. The EQ is based on the measurements of a single unit. YMMV with regard to the very unit you are trying this EQ on.
  • I sometimes use variations of the Harman curve for some reasons. See rational here and here
  • NOTE: the score then calculated is not comparable to the scores derived from the default Harman target curve if not otherwise noted.

OK L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 55.8%
Score Amirm: 88.4%
Score with EQ: 97.0%

Etymotic ER4XR Harman Full EQ

Preamp: -8.20 dB

Filter 1: ON PK Fc 25.8 Hz Gain 8.18 dB Q 0.32
Filter 2: ON PK Fc 266.2 Hz Gain -1.79 dB Q 1.86
Filter 3: ON PK Fc 1431.6 Hz Gain -2.15 dB Q 2.26
Filter 4: ON PK Fc 2151.6 Hz Gain -2.37 dB Q 1.88
Filter 5: ON PK Fc 6540.3 Hz Gain 4.35 dB Q 2.64

Etymotic ER4XR Harman Full EQ.png

The following EQ it targeting Knowles reference curve.
The scores are NOT comparable.

Score no EQ: 56.0%
Score with EQ: 97.1%

Etymotic ER4XR Knowles EQ

Preamp: -11.7 dB

Filter 1: ON PK Fc 29.05 Hz Gain 8.14 dB Q 0.38
Filter 2: ON PK Fc 276.96 Hz Gain -1.71 dB Q 2.17
Filter 3: ON PK Fc 1392.93 Hz Gain -2.12 dB Q 2.55
Filter 4: ON PK Fc 2158.33 Hz Gain -2.47 dB Q 1.7
Filter 5: ON PK Fc 6386.67 Hz Gain 3.94 dB Q 2.8
Filter 6: ON PK Fc 13553.74 Hz Gain 11.69 dB Q 1.8

Etymotic ER4XR Knowles EQ.png


  • Etymotic ER4XR Knowles EQ.txt
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  • Etymotic ER4XR Harman Full EQ.txt
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Last edited:
After the last 2 years I have developed an allergy to all IEMs that cost more than 50/100€. But still great that there are such good products.
What is going on at 250Hz and 18kHz+ on group delay graph? I suspect its flaw of balanced armature drivers. I think the cheaper dynamic driver ER2SE/XR would not only have lower distortion, it would have cleaner group delay, especially in treble.
Thanks Amir!

The point of getting those over 20$ 7Hz Salnotes Zero IEM though...

Would never buy any IEMs like these simply because of ergonomics and fit:rolleyes:
Thanks Amir!

The point of getting those over 20$ 7Hz Salnotes Zero IEM though...
The point is fun: unique experience of getting mad every time when something touch the cable or cable touches something:D
Very interesting and wonderful to have these tested! These had been my favourite prior to the latest generation -- I preferred them over JH13s etc. But with 7Hz Zero 2 on the market, the only obvious advantage for these could be for applications where you need the barrel shape and deep insertion

Back a few years, I would have bought one .. because I didn't know and .. the only references we had were the name, reputation... and price :facepalm: ... yep!
Now, armed with Science and rigorous reviews such as these, (thanks a million @amirm), we are repeatedly shown that several <$50.oo IEM are, gasp!, superior to this one in all areas that matters. Actually, the regulars know that $50.oo seems to be the threshold of diminishing return for IEMs.

One can't seat on one's laurels long in technology. I hope the brand survives, there is a changing of the guard.

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I never thought I could see another Etymotic IEM review by Amir. Thanks!

Distortion may not be so important since the listening test after EQ was good.
Thanks for this review.

Quite disappointing.
Especially the distortion + consequence (volume limitation) raises a No-Go flag for me.
Looking at this review makes me conclude that IEM's have developed a lot over the years! This IEM was launched in year 2016 according to Google.
For me, the ER4XR are one of the best tuned IEMs on the market. They are closest to what I hear with studio monitors. Plus, the trebles are great, very smooth, without any sharpness. Not many headphones have such good treble quality.
Equalizing them to Harman's curve? No, thanks :)
I have had them since they first came out decades ago. I used them mainly for travel, esp plane and train travel, because they isolate outside noise well. I never enjoyed the sound much, but they were all-but alone in the market. And the microphonics from the cable being touched or moved are awful. Why won’t they fix this?

I have the model under review. I almost never use them. They are not pleasing, just sometimes practical.

Oh, and don’t work out with them. Sweat easily gets onto the contacts where the body meets the cable.

All hail Truthear!
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