Sennheiser EM 3732 - Manual (Page 86)

38
Additional information
Additional information
HiDyn plus™ (HDP) noise reduction
The EM 3731/3732 receivers are equipped with HDP , 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.
HDP 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.
HDP has been specially developed for high quality radiomicrophone
systems.
The EM3731/3732 receivers feature a AES3 digital audio output for digital
mixing consoles. In the receiver the audio signal is digitalized as early as
possible so that the noise reduction (compander) can be realized digitally.
Note:
Only transmitters and receivers that are equipped with HDP can work
correctly with each other. If non HDP equipment was mixed with HDP ,
the dynamic range would be drastically reduced and the transmission
would sound blunt and flat.
HDP is permanently active and cannot be
switched off.
Squelch
Depending on the strength of the received RF signal, the receiver’s audio
output is opened or muted. Via the “
Squelch ” menu, the squelch threshold
can be adjusted in 15 steps from 0 to 30 μV.
RF link
Transmitter Receiver
Inherent
of the RF link
noise
EM3732_516551_0108_Sp6.book Seite 38 Dienstag, 18. Dezember 2007 11:55 11