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EN
Additional Information
Glossary
Digital Cinema Sound
General name for surround sound developed by Sony
using digital signal processing technology to allow you to
enjoy powerful theater-like sounds in the comfort of your
own home. In contrast to the former sound field
reproduction based on spaces for performing music,
Digital Cinema Sound was developed solely for movie
enjoyment.
Dolby Surround
Encoding and decoding system of Dolby Surround sound
for consumer use. Dolby Surround decodes the extra
channels on the Dolby Surround-encoded sound tracks of
movie videos or other software and produces sound
effects and echoes that make the action seem to envelop
you.
Dolby Pro Logic Surround
Decoding system of Dolby Surround sound that decodes
sound encoded in two channels into four channels. This
reproduces sound movement and position more naturally
than the former Dolby Surround system. To take
advantage of Dolby Pro Logic Surround, you should have
one pair of front speakers, one center speaker, and one
pair of rear speakers. The rear speaker output is
monaural.
Dolby Digital (AC-3)
Movie sound format developed for theaters by further
expanding Dolby Pro Logic. Dolby Digital (AC-3)
provides stereo rear output, an increased frequency
bandwidth, and an independent sub woofer for the bass
frequencies. (The sub woofer output activates only when
heavy bass effects are necessary, so it is counted as 0.1ch
and the mode is called 5.1ch.) The 5.1 channels are
encoded separately beforehand, offering excellent channel
separation. Further, all sound is processed using digital
signals so there is little deterioration. The “AC-3”
indicates that this is the third Audio Coding method
developed by Dolby Laboratories.
Comparison of Dolby Digital (AC-3) and Dolby
Pro Logic
Item
Dolby Digital
Dolby Pro Logic
(Dolby AC-3)
Process
Digital discrete
Analog matrix
Encoded channels
5.1ch
2ch
Decoded channels
5.1ch
4ch
Rear sound
Stereo
Monaural
Rear bandwidth
3 Hz to 20 kHz
100 Hz to 7 kHz
Independent
Yes
No
sub woofer
Dolby Digital
Dolby Pro Logic
L
C
R
S.W
LS
RS
(Stereo)
L
C
R
S
S
(Monaural)
