Sennheiser RS 130 Instruction Manual page 7

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.
Enhancement of the 3D and the bass portion of the
stereo signal (Fig. 8)
The RS 130 system is equipped with the so-called sound retrieval
system (SRS), which significantly enhances the three-dimensional
and the bass portion of the stereo signal. To activate the sound
retrieval system, move the slide switch "SURROUND" on the
transmitter to the right. The yellow LED "SURROUND" lights up.
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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