Sennheiser HME 25-KA-2 Headphones User Manual


 
6
Technical data
Headphone
Transducer principle dynamic, closed
Coupling to the ear supraaural
Transmission range 30-16.000 Hz
Rated impedance 600 (2 x 1.200 parallel)
Frequency characteristic 97 dB ± 3 dB at 1 kHz, 1 mW
THD < 1 %
Load rating 200 mW
Microphone incl. preamplifier
Transducer Back electret-condenser capsule
noise compensated
Transmission range 300-5.000 Hz
Max. sound pressure level 120 dB
Output voltage 400 mV ± 3 at 114 dB
(as per RTCA/DO-214)
Load impedance 150
Supply voltage typ. 16 V DC,
(8-16 V DC; approx. 8-25 mA
as per RTCA/DO-214)
General data
Weight without cable approx. 170 g
Connecting cable single-sided, length: 1.8 m
Connection plug 3-pole 1/4" (6.35 mm) jack plug,
wired mono, for headphone
PJ-068, 5.25 mm for microphone
Adjusting the microphone gain
According to JTSO approval C58a, the microphone output voltage is factory-
preset to 400 mV. If the microphone output voltage is too high or too low for
your intercom system, it can be re-adjusted on the microphone. To do so, use a
Mic Gain Adjustment
small slotted screwdriver and
turn the ‘Mic Gain Adjustment’
screw (see illustration on the
left) until you have reached the
desired setting.