Sennheiser RS 140 Instructions For Use Manual page 7

headphones automatically turn off. By pressing the TUNE button,
the headphones can be turned on again.
Self-learning automatic level control with memory
function
The transmitter is equipped with an automatic level control which
ensures that the headphones always receive an optimum signal. The
level is continuously adjusted during operation and remains stored
as long as the transmitter is connected to the mains.
Under-modulation (audio signal too low)
With under-modulation, the yellow LED "INPUT LEVEL" flashes
slowly. If this happens, gradually increase the volume of the sound
source. If the audio signal remains too weak, an optimum trans-
mission is not possible. It could be that the transmitter is
deactivated after some time.
Over-modulation (audio signal too high)
With over-modulation, the yellow LED "INPUT LEVEL" flashes rapidly.
If this happens, gradually reduce the volume of the sound source.
Dynamic compression system (Fig. 8)
The RS 140 system is equipped with a switchable dynamic
compression system. This system reproduces soft passages louder
and decreases loud sounds. To activate the dynamic compression
system, move the slide switch "COMPRESSION" on the transmitter to
the right. The yellow LED "COMPRESSION" lights up. If the LED
flashes slowly, gradually increase the volume of the sound source
(see "Under-modulation").
Automatic noise reduction
In addition, the transmitter features a "Noise Gate" function, which
reduces hissing noise when no audio signal is transmitted (e.g.
during pauses).
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