Denon AVR-770SD Operating Instructions Manual Download Page 36

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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).

Types of multi-channel signal

Dolby Digital, Dolby Pro Logic, DTS, high definition 3-1 signals (Japan MUSE Hi-Vision audio), DVD-Audio,
SACD (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.

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.).

Multiple surround speakers

(For 6.1-channel system)

Movie theater sound field

Listening room sound field

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 spkr or 2 spkrs)

•

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.

ENGLISH

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.

SR ch

SL ch

SR ch

SB ch

Change of positioning and acoustic image

with 5.1-channel systems

Movement of acoustic image from SR to SL

Change of positioning and acoustic image

with 6.1-channel systems

Movement of acoustic image from SR to SB to SL

With this set, speaker(s) for 1 or 2 channels are required to achieve a 6.1-channel system (DTS-ES, etc.). Adding
these speakers, however, increases the surround effect not only with sources recorded in 6.1 channels but also
with conventional 2- to 5.1-channel sources. All the Denon original surround modes (see page 28) are compatible
with 7.1-channel playback, so you can enjoy 6.1-channel sound with any signal source.

Number of surround back speakers

Though the surround back channel only consists of 1 channel of playback signals for 6.1-channel sources
(DTS-ES, etc.), we recommend using two speakers. When using speakers with dipolar characteristics in
particular, it is essential to use two speakers.
Using two speakers results in a smoother blend with the sound of the surround channels and better sound
positioning of the surround back channel when listening from a position other than the center.

Placement of the surround left and right channels when using surround back speakers

Using surround back speakers greatly improves the positioning of the sound at the rear. Because of this, the
surround left and right channels play an important role in achieving a smooth transition of the acoustic image
from the front to the back. As shown on the diagram above, in a movie theater the surround signals are also
produced from diagonally in front of the listeners, creating an acoustic image as if the sound were floating in
space.
To achieve these effects, we recommend placing the speakers for the surround left and right channels slightly
more towards the front than with conventional surround systems. Doing so sometimes increases the
surround effect when playing conventional 5.1-channel sources in the 6.1 surround or DTS-ES Matrix 6.1
mode. Check the surround effects of the various modes before selecting the surround mode.