Etymotic ER4 SR/XR Noise-Isolating Earphones Model:ER4SR Studio Reference Rarer than hen's teeth and

Rarer than hen's teeth and soft as a baby's bottom

As with Hugo 2

Be there in 30 seconds

and AAC codec compatibility

with exception of line-level mode

Etymotic ER4 SR/XR Noise-Isolating Earphones Model:ER4SR Studio Reference Rarer than hen's teeth andWhich 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