Denon POA-A1HDCI Stereo Amplifier User Manual


 
Adaptive Decorrelation™
In a movie theater, a large number of surround speakers help create an
enveloping surround sound experience, while in a home theater there
are usually only two speakers. This can make the surround speakers
sound like headphones that lack spaciousness and envelopment. The
surround sounds will also collapse into the closest speaker as you
move away from the middle seating position. Adaptive Decorrelation
slightly changes one surround channel’s time and phase relationship
with respect to the other surround channel. This expands the listening
position and creates—with only two speakers—the same spacious
surround experience as in a movie theater.
THX Ultra2™
Before any home theater component can be THX Ultra2 certified,
it must incorporate all the features above and also pass a rigorous
series of quality and performance tests. Only then can a product
feature the THX Ultra2 logo, which is your guarantee that the Home
Theater products you purchase will give you superb performance for
many years to come. THX Ultra2 requirements cover every aspect
of the product including power amplifier performance, pre-amplifier
performance and operation, as well as hundreds of other parameters
in both the digital and analog domain.
In addition to improvements to the power amplifier with respect
to previous THX Ultra standards, three surround modes have been
added: the THX Ultra2 Cinema mode, THX Music Mode and THX
Games Mode.
THX Ultra2 Cinema
THX Ultra2 Cinema mode plays 5.1 movies using all 8 speakers giving
you the best possible movie watching experience. In this mode, new
THX processing blends the side surround speakers and back surround
speakers providing the optimal mix of ambient and directional surround
sounds.
DTS-ES (Matrix and 6.1 Discrete) and Dolby Digital Surround EX
encoded soundtracks will be automatically detected in Ultra2 Cinema
mode if the appropriate flag has been encoded.
Some Dolby Digital Surround EX soundtracks are missing the digital
flag that allows automatic switching. If you know that the movie that
you are watching is encoded in Surround EX, you can manually select
the THX Surround EX playback mode, otherwise THX Ultra2 Cinema
mode will apply processing to provide optimum replay.
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.
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.
ASA (Advanced Speaker Array)
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 Music
Mode and THX Games Mode.
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 and Re-EQ, THX Timbre Matching, THX Adaptive Decorrelation,
and THX Advanced Speaker Array are trademarks of THX Ltd. THX
may be registered in some jurisdictions. All rights reserved.
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 the 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 AVP-A1HDCI, 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.
Timbre Matching™
The human ear changes our perception of a sound depending on the
direction from which the sound is coming. In a movie theater, there
is an array of surround speakers so that the surround information is
all around you. In a home theater, only two speakers located to the
side of your head are used. The Timbre Matching feature filters the
information going to the surround speakers so that they more closely
match the tonal characteristics of the sound coming from the front
speakers. This ensures seamless panning between the front and
surround speakers.
THX™ Surround EX™
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