VINCENT SV-122 Manuel D'utilisation page 64

ted. All Dolby Surround software offered up to now
contains decoders for Prologic II. As opposed to
Prologic the full HiFi frequency range is covered for
all channels and there are two surround channels.
Dolby Digital 5.1 (AC-3)
Dolby Digital 5.1 (firstly named AC-3) is a digital
audio multi channel format developed in 1992 for
the movie sound recording and playback in the
Dolby Laboratories. It contains up to six independent
channels (two front channels, one center channel,
two surround channels and one low-frequency chan-
nel (LFE)). The first mentioned five channels can
transfer the full audible frequency range (20 to
20,000 Hz), the LFE channel only the low bass fre-
quency range (20 bis 120 Hz). All separate digital
signals are interleaved into one digital data stream
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64
GLOSSARY
that can be transferred via ONE digital cable.
Compression techniques are used to reduce the
huge data rate necessary for this high quality signal
data transfer by the factor of eight. The effective
data rates are 384 and 448 kbit/s. Since 1997
Dolby Digital 5.1 is the standard DVD audio format.
DSP
stands for „Digital Signal Processor". This is a
small microcomputer (IC, chip) designed for the
processing of digital signals (audio or video). It
can, for example, be used to add reverberation or
echo to an audio signal. One of the most important
factors in the perception of sound is reverberation,
that ist the way how the sound is reflected continu-
ously by different objects and walls (similar to
echoes) in the room.