About Surround Sound - Polk Audio I-Sonic 2 Instruction Manual

ABOUT SURROUND SOUND

The DS-2 system offers four modes of operation: Stereo, Dolby Pro
Logic, 2 channel Dolby Digital and Dolby Digital 5.1 surround. You
might wonder, "what is 2 channel Dolby Digital? Isn't Dolby Digital
always 5.1 surround?" The answer is no. Dolby Digital is a digital audio
compression system that provides very high fidelity sound quality in
either 2 or 6 channels. (The six channels are Left and Right front,
Center, Left and Right rear and a Low Frequency Effects channel, or
5.1). The vast majority of Dolby Digital program materials are 5.1
multi-channel recordings. Most DVDs have both 2 channel and 5.1
channel Dolby Digital soundtracks. In most cases the default soundtrack
is the 2 channel Dolby Digital soundtrack and you must manually select
the 5.1 channel soundtrack via the DVD's menu (see your DVD player's
manual for instructions). But some DVDs only have a 2 channel Dolby
Digital soundtrack permitting only Dolby Pro Logic surround sound.
When you see this
on the display:
D D D DIGITAL D
2/0
D D D DIGITAL D PRO LOGIC
2/1
D D D D DIGITAL
3/2.1
STEREO
PRO LOGIC
STEREO
PRO LOGIC
The DS-2 is manufactured under license from Dolby Laboratories Licensing Corporation. "Dolby," "AC-3," and the double-D symbol are trademarks of Dolby Laboratories Licensing Corporation.
That means you are
listening to:
Stereo
Pro Logic Surround
Dolby Digital 5.1 Surround
Stereo
Pro Logic Surround
Stereo
Pro Logic Surround
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You can use the Pro Logic mode with stereo sources such as radio, CD,
and tape to get very good surround sound, even though those sources
are not Dolby Surround encoded. Dolby Surround encoding is
compatible with stereo playback, so conventional stereo programs
sound similar to surround encoded program when played with the Pro
Logic surround mode engaged. You may want to leave the DS-2 in the
surround mode all the time.
The chart below shows which modes are possible with which inputs, and
how to tell which mode you are in by looking at the front panel display.
And your program
material is:
2 channel Dolby Digital
2 channel Dolby Digital
5.1 channel Dolby Digital
2 channel Dolby Surround
(Pro Logic) encoded
2 channel Dolby Surround
(Pro Logic) encoded
2 channel stereo
2 channel stereo
That can be delivered by
these sources:
DVD, DSS satellite TV (only with
special Dolby Digital equipped
satellite receivers), Digital TV
broadcasts (future)
DVD, DSS satellite TV (only with
special Dolby Digital equipped
satellite receivers), Digital TV
broadcasts (future)
Most DVDs, some 12" laserdiscs,
Digital TV broadcasts (future)
Most Hi-Fi video tapes, some TV
broadcasts
Most Hi-Fi video tapes, some TV
broadcasts
FM radio stations, CDs, LP records,
most TV broadcasts
FM radio stations, CDs, LP records,
most TV broadcasts
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