Denon AVR-1905 Operating Instructions Manual page 36

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.
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
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. Furthermore, all the DENON original surround modes (see page 28)
are compatible with 7.1-channel playback, so you can enjoy 7.1-channel sound with any signal source.
2 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.
2 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.
36
Change of positioning and acoustic image
with 6.1-channel systems
FL SW C FR
SL ch SR ch
SB ch
Movement of acoustic image from SR to SB to SL
Speaker setting examples
Here we describe a number of speaker settings for different purposes. Use these examples as guides to set up
your system according to the type of speakers used and the main usage purpose.
1. DTS-ES compatible system (using surround back speakers)
(1) Basic setting for primarily watching movies
This is recommended when mainly playing movies and using regular single way or 2-way speakers for the
surround speakers.
• Set the front speakers with their front
Front speakers
Center speaker
surfaces as flush with the TV or monitor
screen as possible. Set the center speaker
between the front left and right speakers and
Monitor
Subwoofer
no further from the listening position than the
60°
front speakers.
Surround
• Consult the owner's manual for your
speakers
subwoofer for advice on placing the
subwoofer within the listening room.
• If the surround speakers are direct-radiating (monopolar) then place them
60°
slightly behind and at an angle to the listening position and parallel to the walls
at a position 60 to 90 cm above ear level at the prime listening position.
Surround back speakers
• When using two surround back speakers, place them at the back facing the
As seen from above
front at a narrower distance than the front left and right speakers. When using
one surround back speaker, place it at the rear center facing the front at a
slightly higher position (0 to 20 cm) than the surround speakers.
• We recommend installing the surround back speaker(s) at a slightly downward
facing angle. This effectively prevents the surround back channel signals from
reflecting off the monitor or screen at the front center, resulting in interference
and making the sense of movement from the front to the back less sharp.
(2) Setting for primarily watching movies using diffusion type speakers for the surround speakers
For the greatest sense of surround sound envelopment, diffuse radiation speakers such as bipolar types,
or dipolar types, provide a wider dispersion than is possible to obtain from a direct radiating speaker
(monopolar). Place these speakers at either side of the prime listening position, mounted above ear level.
• Set the front speakers, center speaker and
Path of the surround sound
from the speakers to the
subwoofer in the same positions as in
listening position
example (1).
• It is best to place the surround speakers
directly at the side or slightly to the front of
the viewing position, and 60 to 90 cm above
the ears.
Surround
speakers
• Same as surround back speaker installation
method (1).
Using dipolar speakers for the surround back speakers as well is more effective.
• The signals from the surround channels reflect off the walls as shown on the
60°
diagram at the left, creating an enveloping and realistic surround sound
Surround back speakers
presentation.
As seen from above
Surround back
Surround
speaker
speaker
Point slightly
Front speaker
downwards
60 to
90 cm
As seen from the side
Surround back
Surround
speaker
speaker
Point slightly
Front speaker
downwards
60 to
90 cm
As seen from the side