Bose Aviation Headset Series II Owner's guide - Page 21

Technical Information Sound pressure levels (SPL) are relative to 20 micro Pascal. Earphones Damage could occur to avionics equipment if it was manufactured for use only with 600Ω (ohm) headsets. If in doubt, consult the avionics equipment manufacturer. Impedance In mono mode: 480Ω (on) and 190Ω (off) at 1kHz. In stereo mode: left, 500Ω (on), 190Ω (off); right, 2000Ω (on), 190Ω (off). Frequency response 20Hz - 15kHz Sensitivity 90dB SPL measured at 1mW, 1kHz, full volume on flat plate coupler Microphone Bias Required: 8 to 16VDC through 220Ω to 2200Ω Sensitivity: Depends upon bias and radio AC input impedance. Typical output is 300mV at 114dB SPL. To assure proper modulation of your radio, it is recommended that you have your avionics technician adjust its input to match the output of your headset's microphone. Active noise reduction Active Noise Reduction Bandwidth: 30Hz - 700Hz Noise floor 28dBA SPL (typical) Maximum ambient noise level Approximately 118dB SPL at full cancellation Voltage 7-32VDC Current 60mA typical, 120mA maximum operating Fuse/breaker recommended 1/2 amp fast blow (AGC 1/2 fuse) 21