Etymotic Research ER4 Earphones

The SR (Studio Reference) model is tuned for a completely flat, neutral frequency response, making it ideal for critical listening and studio work. The XR (Extended Response) model offers the same precision but adds a slight bass boost, providing a warmer, more engaging sound profile for casual listening.

With an impedance of 45 Ohms, these earphones can be driven by most smartphones, tablets, and laptops without an external amplifier. However, using a high-quality DAC or amplifier can help you extract the maximum detail and clarity from the balanced armature drivers.

Unlike active noise cancellation, which uses electronics to mask sound, these earphones use a deep-insertion design to physically block external noise. This provides up to 42 dB of isolation, which is significantly more effective at blocking high-frequency sounds like speech than most active systems.

The deep-insertion fit is a signature of Etymotic and can feel intrusive at first if you are used to standard earbuds. Most users find that once they select the correct ear tip size and get used to the fit, they are comfortable enough for hours of wear.

Yes, the ER4 series features a detachable, reinforced cable with standard MMCX connectors. This allows you to easily replace the cable if it wears out or upgrade to a different cable type without needing to replace the entire earphone unit.

The small filters located at the nozzle of the earphone prevent earwax and debris from entering and damaging the sensitive balanced armature drivers. They should be replaced periodically—typically every few months—to maintain sound quality and protect your investment.