Denon AVC-A11XV Operating Instructions Manual page 71

Additional Information
2 THX Music Mode
For the replay of 5.1 multi-channel music the THX
Music Mode should be selected. In this mode new
THX processing is applied to the surround channels of
all 5.1 encoded music sources such as DTS and Dolby
Digital to provide a wide stable rear soundstage.
2 THX Games Mode
For the replay of stereo and multi-channel game audio
the THX Games Mode should be selected. In this
mode THX ASA processing is applied to the surround
channels of all 5.1 and 2.0 encoded game sources
such as analog, PCM, DTS and Dolby Digital. This
accurately places all game audio surround
information, providing a full 360 degree playback
environment. THX Games Mode is unique as it gives
you a smooth transition of audio in all points of the
surround field.
2 Advanced Speaker Array™ (ASA)
ASA is a proprietary THX technology which processes
the sound fed to 2 side and 2 back surround speakers
to provide the optimal surround sound experience.
When you set up your home theater system using all
eight speaker outputs (Left, Center, Right, Surround
Right, Surround Back Right, Surround Back Left,
Surround Left and Subwoofer) placing the two
Surround Back speakers close together facing the
front of the room as shown in the diagram will provide
the largest sweet spot. If for practical reasons you
have to place the Surround Back speakers apart, you
will need to go THX Audio Set-up screen and choose
the setting that most closely corresponds to the
speaker spacing, which will re-optimize the surround
sound-field.
ASA is used in three new modes; THX Ultra2 Cinema,
THX MusicMode and THX Games Mode.
2 Boundary Gain Compensation
If your chosen listening room layout (for practical or
aesthetic reasons) results in the most of the listeners
being close to the rear wall, the resulting bass level
can be sufficiently reinforced by the boundary that the
overall sound quality becomes "boomy". THX Ultra2
receivers and controllers contain the BGC (Boundary
Gain Compensation) feature to provide an improved
bass balance. BGC can be selected by choosing "THX
Ultra2 Subwoofer–Yes" from the "Boundary Gain
Compensation" section of the THX Audio setup
menu.
"THX", "Home THX", "Re-Equalization", "Timbre
Matching", "Adaptive Decorrelation", "Advanced
Speaker Array" and "THX Ultra" are trademarks of
THX Ltd.
[6] THX Surround EX
In 1999, a new surround system was launched
simultaneously with the release of the movie "Star
Wars Episode I". "Dolby Digital Surround EX" is a
new movie sound track that greatly enhances the
sense of spatial expression and the positioning of the
surround channel sound. The result is 360 degrees of
movement and moving sound effects that seem to
pass right over the listener's head.
This system was developed jointly by THX and Dolby
Laboratories, fusing THX's idea of improving spatial
expression and achieving a uniform 360 degree sound
positioning with Dolby Laboratories' matrix encoding
technology. Emphasis was placed on compatibility
with the existing system Dolby Digital 5.1-channel,
and the new "surround back (SB) channel" was
added to achieve improvements over
conventional 5.1-channel system in terms of the
positioning of the sound at the rear, the acoustic
image of sound moving from the two sides to the
back as well as sound moving from the front to the
center rear with the multi surround speaker systems
used in movie theaters, thereby enabling various
types of surround sound.
The surround back channel signal is a matrix-encoded
signal inserted into both the Dolby Digital SL
(surround left) and SR (surround right) channels. Upon
playback, the signals are decoded by a high precision
digital matrix decoder within the Dolby Digital decoder
into the SL, SR and SB channels and output as 6.1
channels of signals. With the AVC-A11XV, the signals
further undergo Home THX Cinema processing to
achieve a THX Surround EX system.
Even without the proper environment for playing the
SB channel, Dolby Digital Surround EX signals are
100% compatible with existing 5.1-channel playback
systems, so they can be played as such. In this case,
the SB channel signal is produced as a monaural
signal from both the SL and SR channels, so none of
the signal components are missing. The effects
specific to THX Surround EX (the sense of spatial
expression and the positioning of the sound),
however, are the same as with conventional 5.1-
channel surround systems.
THX and Ultra 2 are trademarks or registered
trademarks of THX Ltd. Surround EX is a jointly
developed technology of THX and Dolby
Laboratories, Inc. and is a trademark of Dolby
Laboratories, Inc. Used under authorization. All
rights reserved.
Audyssey MultEQ XT
There are several factors that can degrade the sound
from even the best loudspeakers in a listening room.
One of the most important is the interaction of sound
from the loudspeakers with large surfaces such as
walls, the floor, and the ceiling in the room. Even with
careful loudspeaker placement and acoustical
treatments, there are significant problems that are
caused by room acoustics. These include reflections
from nearby surfaces and standing waves that are
created between large parallel surfaces in the room.
In a home theater the situation is further complicated
because there are several listening locations. The
effects of room acoustics on the sound arriving at
each person's ears are very different and the result is
the
a listening experience that is degraded in a different
way for every person in the room. It is not uncommon
to have variations in two adjacent seats that are as
large as 10 dB, particularly in the frequency range
below 250 Hz.
The solution to this problem is to apply room
correction after precisely measuring how each
loudspeaker interacts with the room. Because the
room causes variations in the frequency response of
the loudspeakers that are so large from seat to seat,
it is important to measure each loudspeaker at several
locations in the listening room. This should be done
even if there is only one listener. Measurement at a
single location is not representative of the acoustical
problems in the room and will, in most cases, degrade
overall performance.
Audyssey MultEQ XT is the only technology that can
achieve room correction for multiple listeners in a
large listening area. It does so by combining the data
collected at several points in the room from each
loudspeaker and then applying correction that
minimizes the acoustical effects of the room and is
matched to the frequency resolution of human
perception (known as psychoacoustics). Furthermore,
MultEQ XT correction is applied both in frequency and
time domains and so there are no artifacts (such as
smearing of sound or modal ringing) that are
sometimes associated with traditional methods of
room equalization.
In addition to correcting frequency response problems
over a wide listening area, Audyssey MultEQ XT
provides a completely automated sound system set-
up process. It identifies how many loudspeakers are
connected to the amplifiers and whether they are full-
range, satellites, or subwoofers. If there is a least one
subwoofer connected, Audyssey
determines the optimum crossover frequency
between each satellite and the subwoofer(s). It
automatically checks the polarity of each loudspeaker
and alerts the user if there are any that may be wired
out-of-phase relative to the others. It measures the
distance to each loudspeaker from the main listening
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Additional Information
position and adjusts the delays so that sound from
each loudspeaker arrives at the same time. Finally,
Audyssey MultEQ XT determines the playback level
of each loudspeaker and adjusts the volume trims so
that all levels are equal.
The two diagrams below illustrate two examples of
microphone placement for two types of seating
arrangements. There are six measuring positions
shown in each case. Increasing the number of
measuring points will provide a better sampling of the
listening area and produce better results. The dotted
line represents the area in which the room correction
provided by Audyssey MultEQ XT is optimal. The
microphone must be placed at ear height at each
location.
Audyssey MultEQ XT is a trademark of Audyssey
Laboratories. It is licensed under US and National
Patent Applications 20030235318 and 10/700,220.
Additional U.S. and Foreign Patents pending. MultEQ
and the Audyssey MultEQ logo are trademarks of
MultEQ XT
Audyssey Laboratories, Inc.. All rights reserved.
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