The ER3SE (Studio Edition) is Etymotic's high-sensitivity in-ear monitor, ideal for portable use. The ER3SE's high sensitivity and low impedance mean it can be driven by any portable audio player or directly from a phone or laptop. The ER3SE offers professional-quality sound reproduction at an affordable price.

Etymotic acoustic research focuses on noise-isolating, in-ear headphones. The ER4 MicroPro series headphones were the first to be released with balanced armature technology, recognized globally for their precise sound accuracy, serving as a reference for all other headphones. More than 20 years later, these reference-quality headphones remain the most chosen tools by serious sound engineers, audiophiles, and musicians.

The ER3SE is the highest sensitivity, single-driver in-ear monitor. The IEM housings are made from anodized aluminum, with CNC machining and extremely tight tolerances. Using a single Balanced Armature (BA) driver enables an extremely accurate IEM without the complexities of crossovers and helps maintain the size and slimness of the aluminum body. The package includes a user-replaceable cable. Etymotic IEMs are world-renowned for their class-leading passive isolation, providing 35-42 dB attenuation (depending on the ear tips used and insertion depth). In comparison, most custom IEMs provide about 25-28 dB attenuation, while foam ear tips can provide up to 32 dB. The ER3SE is ideal for sound engineers, audiophiles, and budget-conscious consumers looking for in-ear monitors that provide easy manageability and accurate sound reproduction.

Both ER3 models, the ER3SE and the ER3XR, use the same high-sensitivity, low-impedance, balanced armature (BA) drivers. This means there is no need for an amplifier to properly drive the ER3 IEMs. The only difference between the two models is the tuning of the lower (bass) frequencies. The "Studio Edition" ER3SE is tuned for flat frequency response. The "eXtended Response" ER3XR is tuned for high-energy, emphasized bass, increasing the mid-bass by 1-2 dB and the lower by 3-4 dB. Other frequencies are virtually identical to the ER3SE.
The ER3SE is a great choice for budget-conscious audio creators and musicians who require precise and neutral sound reproduction. The ER3SE is also the IEM choice for professional consumers who prefer to listen to their music exactly as it was recorded.
The ER3XR is favored by those who enjoy extra bass and full-bodied sound while listening to music. The extra bass is tastefully delivered without making the ER3XR bass-heavy in the earphones.

The Etymotic target frequency response graph represents a "perceptually flat" frequency response. Our goal is to achieve a flat frequency response curve when the sound notes reach the eardrum. To achieve this, we must consider the average resonance within the ear canal, as IEMs bypass the outer ear structure. As a result, a higher SPL is needed in the 2-5k range (lower treble) to compensate for this resonance. This is the reason for the "bump" in this range.

When tuning in-ear monitors to accurately reproduce a live performance recording, our goal is for the sound reaching the eardrum to match the original performance sound. Achieving this requires consideration of the ear's acoustic properties. The acoustic resonance and horn effects of the ear transform the flat sound signal entering the open ear (2700 Hz) into a high-frequency amplified sound, which is the same response heard at the eardrum in a typical ear. This is the reason for the "hump" seen on the frequency response graph, ensuring that the eardrum perceives a perfectly flat frequency response at all frequencies.