Etymotic ER2 SE/XR Noise-Isolating Earphones Model:ER2XR Extended Response Designed for incredibly comfortable listening

Designed for incredibly comfortable listening

Output impedance: 0

Battery capacity: 1050 mAh

The iPower X uses Active Noise Cancellation2  to cancel all incoming EMI or RFI noise

she wept tears of gold

Etymotic ER2 SE/XR Noise-Isolating Earphones Model:ER2XR Extended Response Designed for incredibly comfortable listeningWhich ER2 is right for you? Both ER2 models, the ER2SE and ER2XR, use the same low impedance dynamic drivers. That means they are easy to drive, and no amplifier is required. The only difference between the 2 models is the tuning of the lower (bass) frequencies. The Studio Edition ER2SE is tuned to have a flat frequency response. The eXtended Response ER2XR is tuned to have an emphasized bass, adding 1 2dB to the mid bass and 3 4dB to the sub bass.