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THX Certified
THX is a Lucasfilm Ltd. program created to achieve maximum
accuracy in the reproduction of movie sound. Movie
soundtracks are recorded on a large "dubbing stage" using
professional equipment. For a soundtrack to be reproduced
accurately at home, special technologies are required. That's
because your "video room" is much smaller than a movie
theater and is acoustically live. What's more, your home theater
system uses speakers that are quite different from those found in
theaters — and there are only six of them. Finally, when you're
at home you sit much closer to the speakers than when you're
in a theater. These differences meant you missed the power,
thrill, and emotion of a good movie when you watched it at
home. Pioneer and Lucasfilm have teamed up to bring the full
glory of realistic cinema sound to the comfort and convenience
of your home.
Pioneer Elite THX/DTS/Dolby Digital A/V receivers offer:
THX Re-Equalization
™
:
A movie theater is large and
acoustically dead, so specialized speakers are used, and typically
placed far from viewers. Since a soundtrack is recorded for
reproduction in such an environment, it sounds overly brilliant
when played at home. THX Re-Equalization compensates for
this acoustic difference by achieving smoother high-frequency
response.
THX Adaptive Decorrelation
™
:
When surround
speakers play back a mono sound, it often seems to come from
one side rather than enveloping you from all sides as in a
theater. THX Adaptive Decorrelation helps to correct for this
inaccuracy by restoring spaciousness on surround signals.
THX Timbre Matching
™
:
Surround sound should
envelop the viewer smoothly and seamlessly. Nothing is more
distracting than when sounds jump from one speaker to
another. By improving the front/surround matching, THX
Timbre Matching ensures smooth movement of surround
sound.
THX Bass Peak Level Management
™
:
Some Dolby
Digital soundtracks produce bass peaks that are undesirable in a
home theater environment. THX Bass Peak Level Management
allows you to control maximum peak levels and properly adjust
them to your home theater system.
THX Loudspeaker Position Time Alignment
™
:
This
feature lets you equalize differences in the distances between
individual loudspeakers and your listening position. Equalizing
these distances ensures both precise synchronization of the
outputs from all speakers and seamless continuity of the
soundfield.
THX Surround EX
THX Surround EX — Dolby Digital Surround EX is a joint
development of Dolby Laboratories and the THX division of
Lucasfilm Ltd. In a movie theater, film soundtracks encoded
with Dolby Digital Surround EX technology are able to
reproduce an extra channel — Surround Back — which has
been added during the mixing of the program. Because
currently available Dolby Digital has 5.1 channels — front left,
front center, front right, surround right, surround left and
subwoofer channels — Dolby Digital Surround EX offers 7.1
channels.
Encoded on special DVD movie releases, the Surround
Back channel places sounds behind the listener. This additional
channel allows more detailed imaging behind the listener and
brings more depth, spacious ambience and sound localization
than ever before. When released on the home consumer market,
movies that were created using the Dolby Digital Surround EX
technology bear a Dolby Digital Surround EX logo on the
packaging. The Pioneer Elite A/V receivers — all with the THX
Surround EX logo — can faithfully reproduce this technology in
the home in the THX Surround EX mode.
THX Select2
The VSX-84TXSi, VSX-82TXS, VSX-81TXV,
and VSX-80TXV all feature THX Select2
certification. This latest THX certification means
that a wide array of listening modes are offered to
enhance your entertainment. Each mode includes Pioneer-
proprietary Advanced Speaker Array (ASA) technology for
optimizing playback of multi-channel sound.
THX Cinema:
This mode plays 5.1-channel movies using all
eight speakers. ASA technology processes audio signals sent to
the surround and surround back speakers in a way that
optimally blends the ambient and directional sound.
THX MusicMode:
This mode is especially suited for multi-
channel music. ASA technology is applied to the surround
channels of 5.1-channel encoded music sources, creating a
wider yet stable acoustic ambience.
THX Games Mode:
A full 360-degree, 3-dimensional acoustic
ambience is created from stereo or multi-channel game audio,
including analog sources and those in PCM, DTS, and Dolby
Digital formats. In addition to placing sound accurately, this
mode allows smooth point-to-point transition of audio, to
further enhance its realism.
*The THX logo is a trademark of THX Ltd., which may be registered in some jurisdic-
tions. All rights reserved.
With the aid of a microphone, included in the
package, the MCACC measures the response from
each speaker and performs the following processes:
(1) Checking the absence (or presence) of connected speakers
The system checks which speakers — front, center,
surround, surround back speakers, and/or subwoofer — are
connected to the A/V receiver.
(2) Detecting speaker size (large or small)
Bass sound for a small speaker is diverted to a large speaker
or subwoofer.
(3) Equalizing the differences of speaker distance from the
listening point
Electronically-generated sound delays, as well as those
caused by speaker distance gaps, are compensated for.
(4) Neutralizing the differences in sound pressure level
Gaps among channels are limited
to ±0.5 dB or less.
(5) Compensating for timbre differences
The frequency response of each speaker is measured and
adjusted for all nine (VSX-84TXSi, VSX-82TXS, and
VSX-81TXV) or five bands (VSX-80TXV). This is
completed with the original "Envelop Compensation"
applied technology, which ensures optimum timbre-
matching with minimum phase variations among channels.
(6) Time-axis compensation
(VSX-84TXSi/VSX-82TXS/VSX-81TXV)
A revolutionary function integrated into Advanced
MCACC. Acoustic treatment can be point-controlled,
either manually or automatically — by units of 20 msec
between 0msec and 80 msec points. Minute adjustment
allows you to create an ideal sound field according to the
acoustic characteristics of various listening environments.
* Room reverberation data, measured by Advanced MCACC, can be checked on the
PC screen or OSD.
(7) X-Curve Compensation
(VSX-84TXSi/VSX-82TXS/VSX-81TXV)
This technology not only calibrates the physical tonal
balance, but also corrects for the human brain's
interpretation of sound as it is affected by the room size.
The result is perfectly flat frequency response.
With all the Elite A/V receivers, you can manually fine-tune
the frequency responses of individual speakers according to taste.
MCACC Functions for the Latest Elite A/V Receivers
(VSX-84TXSi/VSX-82TXS/VSX-81TXV)
In addition to the functions described above, these receivers also
come with the following:
(1) Standing Wave Control
Acoustic standing waves
occur when sound waves
from your speaker system
resonate with those
reflected off the walls.
This can give a negative
effect on the overall sound,
especially certain lower frequencies — resulting in an overly
resonant, "boomy" sound depending on the speaker
positioning, your listening position, and the shape of your
room. The new Pioneer Elite A/V receivers' Standing Wave
Control effectively moderates the resonance in your
listening area. This technology also prevents inappropriate
EQ-setting calibration caused by standing waves.
(2) MCACC Memory (Delays, Levels, and Preset EQ)
MCACC Memory allows receivers to memorize up to six
preset combinations of delays, levels, and EQ settings. This
allows easy switching among combinations, depending on
the listening environment.
SURROUND
BACK FIELD
LOW FREQUENCY
EFFECT
SURROUND FIELD
LEFT
PRESENCE FIELD
Front: Forms the basis of a sound field as
the system's main channels.
Center: Clearly localizes dialog and vocals.
Surround Back: Ensures continuity of surround sound,
adding depth to the soundstage.
SURROUND FIELD
RIGHT
Subwoofer: Enhances suspense and psychological
tension with low-frequency sound effects.
Surround: Enhances surround sound by adding depth to
the sound field and emphasizing the sense of motion.
FL
dB
dB
C
FR LS SB SB RS SW
FL
C
FR LS SB SB RS SW
Before
Compensation
After
Compensation
Automatic Compensation of Sound
Pressure Level
Amplitude
[ dB
]
Frequency [Hz]
OFF
20
-130.0
100
1k
10k
20k
Amplitude
[ dB
]
Frequency [Hz]
ON
20
-130.0
-80.0
-80.0
100
1k
10k
20k
Standing Wave Control Filter
Original Frequency
Standing Wave in a Typical Listening Room
= Standing Wave
OSD for Standing Wave Control
Set-up Mic
Sound Pressure Level and Frequency Response Measured along Time Axis
A Highly Reverberant Room
A Room with No Reverberation
Frequency (Hz)
Level (dB)
Time (msec)
63.0
62.0
61.0
60.0
59.0
58.0
57.0
56.0
55.0
54.0
53.0
10
0
20 30
40
50
60 70
80
90
150
160 63
125 250
500 1k
2k 4k
8k 16k
140
130
120
110
100
Frequency (Hz)
Level (dB)
Time (msec)
63 125
250500
1k 2k
4k 8k
16k
63.0
62.0
61.0
60.0
59.0
58.0
57.0
56.0
55.0
54.0
53.0
10
0
20 30
40
50
60 70
80
90
150
160
140
130
120
110
100
*Graphic images of the listening space's reverberation frequency response, measured by Advanced
MCACC, can be displayed on a PC screen via RS-232C output, with specialized software.
Comparison of 2-Dimensional and 3-Dimensional Compensation
2-Dimensional Compensation
Level
Frequency
3-Dimensional Compensation
Level
Frequency
Time
Home Theater Sound
