[. . . ] [. . . ] SPL Distortion Contact Pressure dynamic, closed circum-aural 20-16. 000 Hz mono: 130 Ohm passive / 180 Ohm active stereo: 260 Ohm passive / 360 Ohm active 98 dB SPL at 1kHz, 1V 90dB SPL at 1 kHz, 1 mW 115 dB SPL at 1 kHz < 1% at 98 dB SPL approx. 5 - 7 N Microphone Type Transducer Principle Frequency range Output voltage Terminating impedance Supply voltage BKE S1-P pre-polarized condenser microphone, noise-compensating 100 Hz - 10 kHz 20 - 80 mV/Pa adjustable, 35 mV/Pa (factory pre-set) 150 - 2. 200 Ohm 8 - 16 VDC General Data Operating temperature Storage temperature Weight w/o cable cable length Power supply - aircraft Power supply - batteries Operating time +5 °F. . . (1. 9 m) 12 - 35 VDC (150 mA / 12 VDC) 2 x AA batteries Application NoiseGardTM digital NoiseGardTM digital w/Bluetooth Type Alkaline / rechargeable batteries Lithium batteries Alkaline / rechargeable batteries Lithium batteries Operating time approx. 25 h Bluetooth data Bluetooth standard Supported profiles Range Made in Germany 2. 1 + DER A2DP, AVRCP, HSP, HFP 32 ft. [. . . ] [. . . ]