Sony STR-DE975 Operating Instructions Manual page 30

You can take advantage of surround sound simply by
selecting one of the receiver's pre-programmed sound
modes. They bring the exciting and powerful sound of
movie theaters and concert halls into your home. You can
also customize the sound modes to obtain the sound you
desire by changing the various surround parameters.
The receiver contains a variety of different sound modes.
The cinema sound modes are designed for use when
playing back movie software (DVD, LD, etc.) encoded
with multi channel surround sound or Dolby Pro Logic.
In addition to decoding the surround sound, some of
these modes also provide sound effects commonly found
in movie theaters.
The virtual sound modes contain compelling applications
of the Sony Digital Cinema Sound digital signal
processing technology. They shift the sound away from
the actual speaker locations to simulate the presence of
several "virtual" speakers.
The music (etc.) sound modes are designed for use with
standard audio sources and TV broadcasts. They add
reverberation to the source signal to make you feel as if
you were in a concert hall or stadium (etc.). Use these
sound modes with two-channel sources like CD and
stereo broadcasts of sports programs or musical concerts.
For more information about the sound modes, see pages
32 - 33.
A.F.D.
The "Auto Format Decoding" sound mode presents the
sound exactly as it was encoded, without adding any
reverberation (etc.).
DCS (Digital Cinema Sound)
The sound fields with DCS marks use DCS technology
When these sound fields are selected, "Digital Cinema
Sound" indicator in the display lights up.
DCS is the concept name of the surround technology for
home theater developed by Sony. DCS uses the DSP
(Digital Signal Processor) technology to reproduce the
sound characteristics of an actual cinema cutting studio in
Hollywood.
To fully enjoy surround sound, you must register the
number and location of your speakers. See "Multi-
Channel Surround setup" starting on page 19 to set the
speaker parameters before enjoying surround sound.