Etymotic ER4 SR/XR Noise-Isolating Earphones noise-isolating providing 35-42 dB attenuation (depending

providing 35-42 dB attenuation (depending on eartips used and the depth of insertion)

Premium earpads and ventilated suspension headband

The full-range speaker driver is a concentration of innovations that lies behind this incredible listening experience

They are lovingly crafted with only the finest components and manufacturing techniques

FULL METAL CNC SCULPTED CHASSIS

Etymotic ER4 SR/XR Noise-Isolating Earphones noise-isolating providing 35-42 dB attenuation (dependingWhich ER4 is right for you? Both ER4 models, the ER4SR and ER4XR, use the same Balanced Armature (BA) drivers. The only difference is the tuning of the lower (bass) frequencies. The ER4SR, being the reference model, is tuned to be as precise and flat as possible. The ER4XR, being the fun model, is tuned with added bass. As you can see from the frequency response graphs below, ER4XR adds 1 2dB to the mid bass frequencies (below 200Hz) and 3 4dB to the