Additional Information
Optimum surround sound for different
sources
There are currently various types of multi-channel signals (signals
or formats with more than two channels).
2 Types of multi-channel signals
Dolby Digital, Dolby Pro Logic, DTS, high definition 3-1 signals
(Japan MUSE Hi-Vision audio), DVD-Audio, Super Audio CD,
MPEG multi-channel audio, etc.
"Source" here does not refer to the type of signal (format) but
the recorded content. Sources can be divided into two major
categories.
2 Types of sources
• Movie audio:
Signals created to be played in movie theaters. In general
sound is recorded to be played in movie theaters equipped with
multiple surround speakers, regardless of the format (Dolby
Digital, DTS, etc.).
Movie theater sound field
FL
SW
C
FR
SL
SR
SL
SB
Multiple surround speakers
(For 6.1-channel system)
In this case it is important to achieve the same sense of
expansion as in a movie theater with the surround channels.
To do so, in some cases the number of surround speakers is
increased (to four or eight) or speakers with bipolar or dipolar
properties are used.
SL : Surround L channel
SR : Surround R channel
SB : Surround back channel (1 speaker or 2 speakers)
• Other types of audio:
These signals are designed to recreate a 360° sound field using
three to five speakers.
In this case the speakers should surround the listener from all
sides to create a uniform sound field from 360°. Ideally the
surround speakers should function as "point" sound sources in
the same way as the front speakers.
These two types of sources thus have different properties, and
different speaker settings, particularly for the surround speakers,
are required in order to achieve the ideal sound.
Listening room
sound field
FL
SW
C
FR
SR
SB
FL
SW
C
FR
SL
SR
48
ENGLISH
Additional Information
Surround back speakers
A 6.1-channel system is a conventional 5.1-channel system to
which the "surround back" (SB) channel has been added. This
makes it easy to achieve sound positioned directly behind the
listener, something that was previously difficult with sources
designed for conventional multi surround speakers. In addition,
the acoustic image extending between the sides and the rear is
narrowed, thus greatly improving the expression of the surround
signals for sounds moving from the sides to the back and from
the front to the point directly behind the listening position.
Change of positioning and acoustic image
with 5.1-channel systems
FL
SW
C
FR
SL ch
SR ch
Movement of acoustic image from SR to SL
Change of positioning and acoustic image
with 6.1-channel systems
FL
C
FR
SW
SL ch
SB ch
Movement of acoustic image from SR to SB to SL
ENGLISH
SR ch