(Video Review) ER4XR Extended Response Earphone

(Video Review) ER4XR Extended Response Earphone

  • High performance balanced armature drivers are precision matched to within 1 dB
  • Specially designed for uncompromising accuracy in the mid to high frequencies with a bit of extra presence in the lower end
  • Sleek, anodized, laser etched aluminum body and braided, reinforced detachable 5 ft cables with custom MMCX connectors
  • 35-42 dB of noise isolation with a max output of 122 dB


From the manufacturer

Etymotic Research, Inc. is an engineering-driven research, development and manufacturing company. The name 'Etymotic' (pronounced 'et-im-oh-tik') means 'true to the ear'. Innovation, education and hearing conservation are central to Etymotic's mission.

ER4XR Extended Response

The World's Most Accurate Earphones Just Got Better!

Over 30 years ago, Etymotic invented noise-isolating, in-ear earphones. Etymotic's original design, developed for auditory research and hearing testing, used balanced-armature receivers and established these speakers as the gold standard for high-definition, in-ear earphones.

  • Detachable 5 foot cable
  • High performance balanced-armature drivers
  • Sleek driver bodies with anodized finish
  • Braided cables for reduced microphonic effect

Why Etymotic?

Etymotic designs products to measure, improve and protect hearing, and enhance the listening experience of music lovers everywhere. Audio engineers, musicians and audiologists at Etymotic have generated over 100 patents issued and pending.

Why ER4XR Extended Response?

ER4XR is the earphone for music lovers and hi-fi enthusiasts who want uncompromising accuracy in the mid-range and high frequencies, but appreciate a bit of extra presence in the lower end.

The ER4XR incorporates the stringent channel matching standard used in the ER4SR and is built with precision machined, anodized and laser-etched aluminum bodies, and features user-replaceable detachable cables.

The ER4XR is ideal for anyone looking for exceptional sound quality with just the right amount of low-end enhancement.


  • Frequency response 20Hz-16kHz
  • Channel matched to within 1dB from 100Hz-10kHz
  • 35-42 dB noise isolation
  • Impedance 45 ohms
  • Sensitivity: 98 dB SPL at 1kHz, 0.1V drive level
  • 122 dB maximum output
  • Assembled and precision matched in the United States

User Detachable Cables

To detach the cables, pull the cable connector away from the earphone body. Pull straight out-Do Not Twist.

To attach the cables, align the key tab on the cable connector with the notch in the body of the earphone. Press together until it snaps in place.

Changing the Filters

Etymotic earphones have special filters that smooth the frequency response and prevent earwax from entering the earphones. The filters are located at the end of the earphone and are visible when the eartip is removed. When a filter becomes clogged it should be replaced. Filters should be changed when output decreases or sound quality declines.

In The Box

ER4XR Extended Response earphones.

Assorted eartips and 1/4" stereo phone adapter.

Filter removal tool and replacement filters.

Shirt Clip and Carrying Case.

Performance Certificate.

© 2021 Booms Beat, All rights reserved. Do not reproduce without permission.
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