Sennheiser SYSTEM 2015 Instructions For Use Manual page 47

HDX noise reduction system
Transmitter
You can hear the difference:
This product is equipped with HDX, the Sennheiser noise reduction system that reduces RF interference. It
increases the signal-to-noise ratio in wireless audio transmission.
which compresses the audio signal in the transmitter in a 2:1 ratio (related to dB) to lift it above the inher-
ent noise floor of the RF link. A 110 dB dynamic range signal is thus transmitted with an effective dynamic
range of only 55 dB, which is above the 60 dB noise floor of the RF link. In the receiver the signal is expanded
in an identical and opposite way in a 1:2 ratio to restore the original signal, at the same time reducing the
RF noise to below the noise floor of the receiver.
HDX has been specially developed for high quality RF microphone systems.
Note:
Only transmitters and receivers that are equipped with
HDX equipment was mixed with HDX, the dynamic range would be drastically reduced and the trans-
mission would sound blunt and flat.
RF link
Inherent
noise
of the
RF link
HDX
HDX is permanently active and cannot be switched off.
Receiver
HDX is a wideband compander system
can work correctly with each other. If non
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