Yamaha DSP-A990 Operation Manual page 7

Dolby Pro Logic Surround
The Dolby Pro Logic Surround Decoder program lets you
experience the dramatic realism and impact of Dolby Surround movie
theater sound in your own home. Dolby Pro Logic gets its name from
its professional-grade steering logic circuitry, which provides greater
effective channel separation for a much higher degree of realism than
the "passive" Dolby Surround circuits found in today's typical home
audio/video equipment. Dolby Pro Logic Surround provides a true
center channel, so that there are four independent channels, unlike
passive Dolby Surround, which has in effect only three channels: left,
right, and rear. This center channel allows listeners seated in even
less-than-ideal positions to hear the dialog originating from the action
on the screen while experiencing good stereo imaging.
This Dolby Pro Logic Surround Decoder employs a digital signal
processing system. This system improves the stability of sound at
each channel and crosstalk between channels, so that positioning of
sounds around the room is more accurate compared with
conventional analog signal processing systems.
In addition, this unit features a built-in automatic input balance
control. This always assures you the best performance without
manual adjustment.
Manufactured under license from Dolby Laboratories Licensing
Corporation. Additionally licensed under Canadian patent number
1,037,877. "Dolby", "Pro Logic", and the double-D symbol are
trademarks of Dolby Laboratories Licensing Corporation.
Dolby Pro Logic Surround
Additionally you can enjoy sound environment created by the
combination of Dolby Pro Logic and YAMAHA DSP. Precise sound
movement and orientation by the Dolby Pro Logic technology is
added to sound fields which are precisely recreated on the
basis of actual acoustic environments by the DSP technology,
so it is suitable for any Audio/Video source with video image.
This combination is used on sound field programs No. 8 through
No. 11, and "Enhanced DOLBY PRO LOGIC" of No. 12.
CINEMA DSP
7ch
The YAMAHA "CINEMA DSP" logo indicates these programs are
created by the combination of Dolby Pro Logic and YAMAHA DSP
technology.
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DSP
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