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Tactile
Transducer - A
device that turns electrical energy into mechanical
energy, usually used to shake the seating in a theater.
Effective in providing visceral impact without
increasing the system's actual SPL level.
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Tape
Monitor - The
connection on your receiver that has both input and
output designed to loop into your circuit for the
purposes of recording while listening to another source.
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THD
-
Abbreviation for
Total Harmonic
Distortion. Harmonic Distortion is a means for
measuring Nonlinear Distortion. Nonlinear Distortion is
a form of signal processing error that creates signals
at frequencies that are not necessarily present in the
input. THD is determined by measuring the size of each
of the new frequencies that are created by the source of
the distortion. The new frequencies are called
"harmonics" because they exist at frequencies that are
integer multiples of the input signal.
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THX
- Abbreviation for Tomlinson Holman Experiment.
Not a format but a standard created by Lucasfilm for
motion picture viewing. The standard takes into account
several aspects including audio and video and sets
specific requirements for how these are presented.
Higher quality Home Theater equipment has the THX logo
which just means it's certified by Lucasfilm that it
meets the THX standards. THX is a set of technical
standards developed by Lucasfilm to ensure that
moviegoers see and hear a film at optimum performance
levels: as the director intended. This comprehensive
set of standards includes rigorous specifications
designed to optimize equipment, room acoustics,
background noise levels, and projection and viewing
angles. Think of THX as the auditorium itself.
The THX Sound System was developed in 1982 during the
production of Return of the Jedi. Inspired by George
Lucas' interest in upgrading film presentation standards
in the industry, Lucasfilm's Corporate Technical
Director, Tomlinson Holman, began to identify problems
related to theatre sound. Holman noted theatre
audiences were not hearing what was recorded in the film
studio - many of the subtle sounds were missing. His
innovative approach was to consolidate existing
performance standards into a new system which included
theatre acoustics as well as sound equipment. THX is a
sound system designed specifically to reproduce film
sound exactly as it was recorded by the filmmaker.
The THX Sound System is the only program of its kind to
consider all aspects of a theatre's audio and visual
performance, including architecture, acoustics and
equipment. "THX is really a performance criteria; it's
not a specific set of components," says Holman. The
system was created to complement advances made by Dolby
Laboratories in decoding sounds in the sound track which
concentrates on the "A-Chain." The THX Sound System
concentrates on the "B-Chain" of a theatre's sound
system. The "B-Chain" is comprised of customized
acoustical design work for each auditorium, a special
screen speaker installation method, a proprietary
electronic crossover network, and rigorous audio
equipment specifications and performance standards.
Upon completion of a THX Sound System installation, the
theatre is tested by a THX engineer to make sure it
meets both THX environmental technical criteria and
recommended industry standards for high quality visual
and sound presentation. Theatres are recertified to
ensure that optimum quality is maintained.
A certified THX theatre carries several important
advantages for the movie-goer. The audience enjoys a
more naturally balanced sound that uniformly reaches
every seat in the auditorium, improved dialog
intelligibility and decreased bass distortion. Better
stereo localization makes the sound appear to travel
across the screen with action. A frequency range that
is wider by a full octave in both bass and treble allows
patrons to hear higher highs and lower lows. The
combined result is the reproduction of the same clear,
dynamic sound originally created by the filmmaker.
Home THX Audio Systems, developed by George Lucas' THX
Division, have become the world's standard for film
enjoyment in the home. For over 15 years, THX has
licensed its patented technology to leading A/V and PC
manufacturers worldwide. The legendary training program
has certified more than 1300 dealers as among the
highest qualified to sell and install Home THX products.
THX also certifies home video software through the THX
Digital Mastering Program, ensuring that DVD software,
laser discs and VHS videotapes provide the best image
and sound quality possible through the use of patented
THX technology and our unique quality control expertise.
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THX
Select - Certification program for speakers
and receivers that assures a base level of quality and
performance when played in a room that's between 2,000
and 3,000 cubic feet.
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THX
Surround EX -
Establishing a new benchmark for multi-channel sound,
Lucasfilm THX has announced THX Surround EX a home
theatre application of the cinema surround sound
technology that made its theatrical debut with the
opening of Star Wars: Episode I The Phantom Menace. THX
Surround EX is an enhancement to digital sound that
decodes a back surround channel in a film soundtrack
allowing for dramatic 360° surround sound effects that
are smoother and more accurately placed either directly
behind or directly beside a viewer.
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THX
Ultra - Certification program for speakers,
receivers, and amplifiers that assures a base level of
quality and performance when played in a room that's
greater than 3,000 cubic feet.
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THX
Ultra 2 - The newest certification from THX,
THX Ultra 2 requires amplification for seven channels,
boundary compensation for subwoofers, and stricter
requirements for amplifiers and speakers than THX Ultra.
Dipole speakers are used for the side surround
channels. Monopole speakers are used for the surround
back channel and are placed next to each other. The
Ultra 2 processor accommodates both 5.1 EX/ES
soundtracks, as well as multi-channel audio recordings
by directing ambient sounds to the dipole speakers and
discrete effects/sounds to the back channels.
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Timbre
- A qualitative characteristic of audio introduced by
your choice in speakers. Timber can be called color of
sound from your speakers, timber tends to be unique to
speaker designs and manufacturers.
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Timbre
Matching -
Using speakers of similar timbre through your Home
Theater system is timbre matching. Timbre matching is
just about guaranteed when you purchase a speaker system
where all the speakers are by the same manufacturer
designed to work together, but it's not the only way to
get good timbre matching. Well matched speaker sets
will make sound consistent as audio makes the transition
from speaker to speaker.
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Toslink
- A fiber optic cable used for digital connection
between audio components (S/PDIF).
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Transducer - Any device that converts one
form of energy into another form of energy, specifically
when one of the quantities is electrical. Thus, a
loudspeaker converts electrical impulses into sound
(mechanical impulses), a microphone converts sound into
electrical impulses, a solar cell converts light into
electricity, etc.
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Transient Response
- The ability of a speaker to respond to
any sudden change in the signal without smearing or
blurring the sound. A speaker that can react quickly to
rapid changes in sound has "good transient response".
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Transmission Line - A (sub)woofer cabinet
design where the driver is mounted at one end of a tube
with the same diameter as the radiating area of the
driver and a length of 1/4 wavelength of the 3dB down
frequency. This "tube" may or may not be round and may
be folded to decrease the size of the cabinet.
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Treble
- High pitched sounds or "highs". Generally anything
greater than 3kHz is treble.
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Tri-wiring
- The use
of three pairs of separate speaker wire from the same
amplifier to separate bass, midrange and treble inputs
on the speakers.
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Tuner
- Part of your receiver that tunes in radio stations.
There are standalone components for audio systems
called tuners dedicated for this purpose.
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Tweak
- To fine tune your audio system by employing
improvements or methods believed to improve sound.
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Tweeter
- A speaker driver
designed to reproduce high frequencies; usually those
over approximately 5,000 to 10,000 Hz.
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Two-way
- A type
of loudspeaker that divides the audio spectrum into two
parts, usually to be fed to a woofer and tweeter. |
