MODEL- ER-4B               VENDOR- ETYMOTIC RESEARCH
    
FEATURES- ER 4B (Binaural) microPro Noise Isolating Earphones
       ER-4B (Binaural) earphones are for the binaural recording 
        enthusiast. The ER-4B is an ideal earphone for use with material 
        that has not been equalized for loudspeaker playback. It was 
        developed from the ER-1 earphone that is referenced to a flat 
        diffuse field and used primarily for speech reception research, 
        where the goal is to produce the same frequency response at the 
        eardrum as would be produced in the live situation. 
    Includes ER-4 MicroPro earphones, 5 ft. cord with 3.5 mm stereo phone 
      plug, 1/4" stereo phone adapter plug, Six 3-flange eartips, 10 foam 
      eartips, Filter changing tool, 4 replacement filters, Shirt clip,
      Pouch and Storage box.
* Response Accuracy 
   ER-4 MicroPro Earphones are designed to match the acoustic response of 
   the open ear. Music is naturally bright, but not harsh. The lack of 
   coloration results in smooth treble, full bass, clear and natural piano, 
   percussion and orchestral music. 
* Noise Reduction 
   ER-4 MicroPro Earphones provide the highest isolation of any earphone: 
   35~42 dB (two to three times that of active noise-canceling earphones). 
   ER~4 MicroPro earphones reduce sound naturally, without the added 
   weight, bulk, or external power supply required for active noise-
   canceling. 
    - 3-flange eartips: 35 dB external noise isolation (NRR = 22dB)
    - Black foam eartips: 42 dB external noise isolation (NRR = 32dB) 
     
  -- SPECIFICATIONs ----------------------------------
FREQUENCY RESPONSE- 50 ~ 10 kHz +/- 2 dB
                    20 ~ 16 kHz +/- 4 dB
TRANSDUCER TYPE   - balanced armature
1 kHz SENSITIVITY - 108 dB SPL for a .79v input
IMPEDANCE         - 100 Ohms nominal
MAXIMUM OUTPUT    - 122 dB SPL
CONTINUOUS INPUT  - Maximum 3.0 Vrms
WEIGHT            - less than 1 oz. 
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