ENGLISH
Surround back speakers
The THX Surround EX format adds new "Surround Back" (SB) channels to the conventional 5.1-channel system.
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
Speaker(s) for one or two channels are required in order to achieve a THX Surround EX system with the AVC-
A1SR. Adding these, however, allows you to achieve stronger surround effects not only with sources recorded
in THX Surround EX, but also with conventional 2- to 5.1-channel sources. The WIDE SCREEN mode is a mode
for achieving surround sound with up to 7.1 channels using surround back speakers, for sources recorded in
conventional Dolby Surround as well as Dolby Digital 5.1-channel and DTS Surround 5.1-channel sources.
Furthermore, all the Denon original surround modes (see page 32) 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
With THX Surround EX, the surround back channel consists of one channel of playback signals, but we
recommend using two speakers. When using dipolar speakers 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 THX Surround EX mode. Check the
surround effects of the various modes before selecting the surround mode.
36
Change of positioning and acoustic image
with THX Surround EX system
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. For THX Surround EX systems (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.
Front speakers
• Set the front speakers with their front
Center speaker
surfaces as flush with the TV or monitor
screen as possible. Set the center
speaker between the front left and right
Monitor
speakers and no further from the listening
Subwoofer
position than the front speakers.
45°
• Consult the owner's manual for your
Surround
subwoofer for advice on placing the
speakers
subwoofer within the listening room.
• If the surround speakers are direct-radiating (monopolar) then place them
slightly behind and at an angle to the listening position and parallel to the
walls at a position 60 to 90 centimeters (2 to 3 feet) above ear level at the
prime listening position.
Surround back speakers
• When using two surround back speakers, set them at the back facing front
As seen from above
and with both speakers at the same distance from the listening point. 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.
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.
• Connect the surround speakers to the surround speaker A jacks on the AVC-
A1SR and set all settings on the setup menu to "A". (This is the factory
default setting. For details, see page 9.)
(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 (THX) 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.
Path of the surround sound from the
speakers to the listening position
• Set the front speakers, center speaker
and subwoofer in the same positions as
in 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
Surround
above the ears.
speakers
• Same
as
installation method (1).
• Connect the surround speakers to the surround speaker A jacks on the AVC-
A1SR and set all settings on the setup menu to "A". (This is the factory
default setting. For details, see page 9.)
• The signals from the surround channels reflect off the walls as shown on the
Surround back speakers
diagram at the left, creating an enveloping and realistic surround sound
As seen from above
presentation.
For multi-channel music sources however, the use of bipolar or dipolar
speakers mounted at the sides of the listening position may not be
satisfactory in order to create a coherent 360 degree surround sound field.
Connect another pair of direct radiating speakers as described in example (3)
and place them at the rear corners of the room facing towards the prime
listening position.
Surround back
Surround speaker
speaker
Front speaker
60 to 90 cm
As seen from the side
This effectively prevents the surround back
Surround back
Surround speaker
speaker
Front speaker
60 to 90 cm
surround
back
speaker
As seen from the side
Point slightly
downwards
Point slightly
downwards