Etymotic Research
Etymotic ER4SR
Best in-ear monitor for audiophiles seeking studio-grade accuracy and noise isolation.
The Etymotic ER4SR is a high-performance, single-driver in-ear monitor designed for exceptional audio accuracy. Crafted from CNC-machined anodized aluminum, these earphones feature a user-replaceable, reinforced twisted cable for enhanced durability. Renowned for their class-leading passive noise isolation, they achieve an attenuation of 35-42 dB, making them ideal for sound engineers, audiophiles, and consumers seeking the most precise in-ear monitors available. The ER4SR offers a flat frequency response, ensuring music is heard exactly as it was recorded, with a focus on clarity and detail across all frequencies.
$339.96
Owner Satisfaction
4.5
/ 5
Category Rank
791
/ 6142
#791 in Headphones
Price vs Category Average
-42%
Below average
Frequency Response
2016
/ Hz – kHz
Who it's for
- Audio professionals and purists demanding neutral, honest sound reproduction
- Commuters and travelers needing total silence in noisy environments
- Long-term owners prioritizing rugged construction and replaceable components
Who should skip it
- Listeners with sensitive ears who dislike deep-insertion earphone designs
- Audiophiles seeking an expansive, airy, and out-of-head soundstage
- Casual users who prefer a quick, hassle-free fit
Performance breakdown
Audio Accuracy
Reference-grade flat response delivers music exactly as the artist intended.
Noise Isolation
Class-leading attenuation effectively silences the chaos of the outside world.
Build Durability
CNC-machined aluminum housing provides a rugged, professional-grade foundation.
Comfort and Fit
Deep insertion design offers unmatched stability but requires an adjustment period.
Serviceability
User-replaceable cables and filters ensure a significantly longer product lifespan.
Driver Precision
Single balanced armature delivers exceptional clarity without phase-related crossover distortion.
Key Specs
Frequency Response
20 Hz – 16 kHz
Transducers
High-performance single balanced armature per channel
Noise Isolation
35 dB using silicone eartips, 42 dB using foam eartips
Impedance
45 Ohms @ 1kHz
Sensitivity
98 dB @ 1kHz, 1mW
Maximum Output (SPL)
122 dB
Cable
Detachable 5ft reinforced, twisted with 3.5mm gold-plated stereo plug
Replaceable ACCU Filters
Yes
Features
- Exceptional passive noise isolation (35-42 dB)
- High-performance single balanced armature driver
- CNC-machined anodized aluminum housing
- User-replaceable reinforced twisted cable with MMCX connectors
- Includes a variety of eartips for a secure fit
- Includes filter removal tool and replacement filters
- Comes with a zippered storage case
What customers say
Customers consistently praise the Etymotic ER4SR for its exceptional sound accuracy and detailed audio reproduction, often describing it as a true reference monitor. The clarity and neutral presentation are standout features, making it a favorite for critical listening. Users also appreciate the robust build quality and durable design, which contribute to a sense of long term reliability. While the deep insertion fit can require adjustment for some, the resulting passive noise isolation and immersive listening experience are highly valued, reinforcing its reputation for delivering premium audio performance.
Know before you buy
The 'SR' stands for Studio Reference. These earphones are specifically tuned for a flat, neutral frequency response, making them ideal for professional monitoring and critical listening where accuracy is the priority.
The ER4SR provides exceptional passive isolation, blocking between 35 and 42 dB of external noise depending on the eartips used. Unlike active noise cancellation, this is a physical seal that works without batteries and is particularly effective at blocking out high-frequency sounds.
Because they are designed to sit deep in the ear canal to achieve their signature isolation, the fit can feel intrusive at first. The package includes a variety of eartips, so experimenting with different sizes and materials is essential to finding a comfortable, secure seal.
Yes, the ER4SR features a user-replaceable, reinforced twisted cable that connects via standard MMCX connectors. This allows you to easily swap the cable if it wears out or if you prefer to use a third-party balanced cable.
The filters protect the balanced armature drivers from earwax and debris, which can degrade sound quality over time. They are user-replaceable, and the kit includes a specialized tool to make the process simple and quick.
With an impedance of 45 Ohms and a sensitivity of 98 dB, the ER4SR can be driven by most smartphones and laptops. However, using a high-quality DAC or amplifier can help ensure you are getting the cleanest signal and full dynamic range from the drivers.
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$340