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Etymotic ER4SR Review


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  • Super-accurate sound
  • Great mid-tone
  • Excellent isolation with foam tips


  • Foam tips make sound harsh
  • Invasive fit

Key Specifications

  • Review Price: £329.99
  • Removable MMCX connector cable
  • 20Hz - 16kHz
  • Balanced armature micro-driver
  • Triple-flanged tips
  • Foam tips

What are the Etymotic ER4SR and ER4XR?

The Etymotic ER4SR and ER4XR are high-end earphones, sitting right at the top of Etymotic’s range of in-ears. Both models share the same design and price, but offer a slightly different sound.

These headphones aim for accuracy more obsessively than most, even among rival £300 units, and offer the finest mid-range tone you’ll hear at the price. Their odd fit will not sit well with everyone, though.

Related: Best Headphones 2017
Etymotic ER4SR 5Etymotic ER4SR earphones on a white background.

Etymotic ER4SR and ER4XR – Design and Comfort

The Etymotic ER4SR and ER4XR are the latest in a long-running series of tube-like earphones. With most in-ears, it’s only the tips that dock in your ears; the Etymotic, however, can be pushed in much further than most in-ear monitors (IEMs). As such, some might not like the feel; it’s invasive.

However, it’s also perhaps necessary. The sound produced by these earphones isn’t of the bold kind, where it remains unaffected by lots of ambient noise, so the deep-dive design is matched with equally hardcore tips.

Etymotic ER4SR 7Etymotic ER4SR in-ear monitor held in a person's palm

Accompanying the in-ears are triple-flanged silicone tips and custom foam ones too. In particular, the foam tips are super-effective, with isolation that’s on a par with using a decent pair of earplugs. You’d never guess that earphones this slight would be capable of such effective isolation. No doubt this is helped by the lack of ports to “let in” the outside world.

Isolation is valued over pure comfort, though. On the first few wears of the ER4SR and ER4XRs, I found the foam tips a little scratchy and the long triple-flanged tips tickled my inner ear in a slightly disconcerting way. However, following a few days’ use, this was no longer an issue. Besides, these niggles were present in the ER4PT and its predecessors.

New this time round is the Etymotic ER4SR and ER4XR’s metal shells and removable cables. The barrels of each earpiece detach, with an MMCX connector joining the cable to the part that holds the drivers.

There’s always a worry that this type of connector will become loose over time, but Etymotic says it has tested the design to ensure that normal lateral pressures won’t have any such effect. Plus, the in-ears come with a two-year guarantee to provide some peace of mind.

Etymotic ER4SR 3Etymotic ER4SR earphones with accessories and carrying case.

This new design makes replacing the cable easy – although, since it’s a typical high-quality kevlar-reinforced lead, most of you shouldn’t have any problems. Like a lot of earphones for audio enthusiasts, there’s no phone remote.

The one part of these in-ears that you will have to replace after a while is the filter in each earpiece. These simply keep any ear gunk away from the drivers, sitting over the tiny aperture of each tube. Additional filters and a filter-replacing tool come in the box. As does a 6.3mm adapter, a little carry case and a shirt clip.

Etymotic ER4SR and ER4XR – Sound Quality

The Etymotic ER4SR and ER4XR are uncompromising when it comes to sound. These are true high-end earphones, using balanced armature micro-drivers that steer clear of the easy wins of super-revealing bright treble or pounding bass.

Their mid-range shines, with detail and intricacy that – with any luck – will reveal to those who are new to expensive earphones where all that money goes. Although the Etymotic ER4SR and ER4XR aren’t truly huge-sounding earphones, the extent to which they hold up to ultra-close listening makes this a non-issue. The texture of vocals is just so well realised here.

Etymotic ER4SREtymotic ER4XR and ER4SR earphone boxes side by side.

Mid-range quality is the main reason to buy these earphones, but here there’s a clear difference in character between the two models. To explain: the “SR” of the ER4SR stands for studio reference, and the “XR” of the ER4XR Extended Response.

The XR pair is fuller and bassier; the SR ultra-restrained. This makes the ER4XR’s mids a little smoother; more plump. You don’t lose out on detail, but the sense of definition is a little relaxed. The sound is easier on the ear, but isn’t necessarily better as such.

Note that, with both earphones, but the ER4SRs in particular, sound is hugely affected by the kind of tip that’s used. While the foam tips provide unbeatable isolation, they also cause the upper-mids to sound quite harsh. I preferred the ER4SR earphones with the silicone tips.

Etymotic ER4SR 9Etymotic ER4SR earphones packaging and carrying case.

The other main difference in sound between the ER4SR and ER4XR is in the tone of the bass. Like the mids, the bass is stripped back in the ER4SRs; there’s decent tone, it’s incredibly fast and nimble, but there isn’t a lot of it.

Until you ears bed into its style, and you appreciate the depth of the bass – it isn’t weak, just sparing – it sounds a little light. The Etymotic ER4XR have an extra few decibels of bass, losing just a hint of the ER4SR’s restraint, but making the sound more fun for casual listening.

These two pairs of earphones have different drivers, so the sound difference isn’t only the results of the XR having a tweaked internal structure.

The treble in both models is similar. These aren’t particularly bright headphones, the higher frequencies slotting Lego-like into the mid-range without trying to pull focus away from them.

In the past, some have called Etymotic’s earphones “clinical”. I don’t get that from either pair of earphones – but particularly the ER4XRs. They simply adhere to some basic, traditional principles of sound quality, and a recognition that once you reach a certain level in headphones, the most telling element of any pair is the mid-range.

Etymotic ER4SR 11Etymotic ER4SR earphones on a white background.

Should I buy the Etymotic ER4SR or ER4XR?

These aren’t party earphones, with their style rewarding concentrated listening; not so much the music listening en route to work.

In terms of sound quality, the Etymotic ER4SR and ER4XR are worth the asking price, mainly thanks to the quality of the mids. The Jays q-Jays offer more revealing treble and the Shure SE535 greater power; which you opt for will depend on your priorities.

There are some elements that might put off those who like the sound profile, though. The Etymotic ER4SR and ER4XR fit is invasive, and the extent to which the foam tips can spoil the sound is quite surprising.


Great earphones for those who value accuracy of sound.

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