Etymotic Research ER4SR Reference Earphones Sennheiser When tuning in-ear monitors to

When tuning in-ear monitors to accurately reproduce a recording of a live performance

Crystal Clear Audio: Two Decades in the Making

great sound

Our patented algorithm perfectly compensates for the internal delay generated by a noise cancellation loop

High-quality

Etymotic Research ER4SR Reference Earphones Sennheiser When tuning in-ear monitors toOverview ER4SR is the highest performing single driver in ear monitor. The IEM shells are made of anodized aluminum, CNC machined with extremely tight tolerances. Using a single Balanced Armature (BA) driver allows for extremely accurate IEM without the added complexity of crossovers, and helps keep the aluminum body small and slim. The included high quality user replaceable cable is reinforced and twisted, to improve longevity and durability.