Sennheiser EK 500 G2 - Manual (Page 28)

28
Additional information
HDX noise reduction
Progress you can hear:
The evolution wireless G2 series is equipped with HDX , the
Sennheiser noise reduction system that reduces RF
interference. It increases the signal-to-noise ratio in
wireless audio transmission to more than 110 dB.
HDX is a wideband compander system which compresses
the audio signal in the transmitter in a 2:1 ratio (related to
dB) to lift it above the inherent 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
radiomicrophone systems.
Note:
Only transmitters and receivers that are equipped with
HDX can work correctly with each other. If non HDX
equipment was mixed with HDX , the dynamic range
would be drastically reduced and the transmission
would sound blunt and flat.
HDX is permanently active
and cannot be switched off.
Wireless transmission systems
With the ew 500 G2 series, Sennheiser puts an end to cable
tangles and enables complete freedom of movement. The
systems operate exclusively in the UHF band. UHF
transmission is extremely reliable and is far less prone to
interference than the overcrowded VHF band – harmonics
from mains units, fluorescent tubes, refrigerators,
computers, etc. are virtually eliminated. Also indoor
propagation of UHF radio waves is better than VHF so that
the RF power can be k ept low – this is also an advantage
RF link
Transmitter Receiver
Inherent noise
of the RF link