Sennheiser W300 IEM - Manual (Page 38)

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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. 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 300 IEM G2 system, 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 kept low – this is also an advantage when using multi-channel
systems. Finally, UHF frequency ranges are being approved all over the world
for radiomicrophone usage – in some countries licence-free.
Correct adjustment of transmitter sensitivity is vital. Too high and you get
overmodulation and distortion, too low and you get undermodulation and a
noisy signal. Please set the sensitivity correctly for the microphone/usage
and check it before every performance to ensure best operation.
RF link
Transmitter Receiver
Inherent noise
of the RF link
ew300_350_IEM_INT.book Seite 36 Freitag, 7. März 2008 8:55 08