THX

THX is the trade name of a high-fidelity sound reproduction standard. It was used for movie theaters, screening rooms, home theaters, computer speakers, gaming consoles, and car audio systems.
"THX" stands for "Tomlinson Holman's eXperiment". THX was developed by Tomlinson Holman at George Lucas's company Lucasfilm in 1983 to ensure that the soundtrack for the third "Star Wars" movie, "Return of the Jedi", would be accurately reproduced in the best venues.
The THX system is not a recording technology, and it does not specify a sound recording format. All sound formats, whether digital (Dolby Digital, SDDS) or analog (Dolby SR, Ultra-Stereo), can be "shown in THX." THX is mainly a quality assurance system. THX-certified theaters provide a high-quality, predictable playback environment to ensure that any movie soundtrack mixed in THX will sound as near as possible to the intentions of the mixing engineer. THX also provides certified theaters with a special crossover circuit whose use is part of the standard. Certification of an auditorium entails specific acoustic and other technical requirements; architectural requirements include a floating floor, baffled and acoustically treated walls, no parallel walls (to reduce standing waves), a perforated screen (to allow center channel continuity), and NC30 rating for background noise.
Applications.
THX sets strict standards for high quality sound and images.
According to Tomlinson Holman, the inventor of the THX system, the name of the technology was deliberately chosen because it contained both a reference to his name, and to Lucas's early movie "THX 1138". The original name was "Tom Holman's Crossover" (Crossover being sometimes referred to as Xover) or the "Tom Holman eXperiment."
THX Ltd., the company that licenses THX and the associated technology, is based in San Rafael, California, but has offices in Burbank and Hollywood.
THX launched a certification program for HD video products to ensure HD projectors, LCDs, plasmas and DVRs meet high standards for quality. The TiVo Series3 HD DVR and a number of projectors from Runco and Vidikron became the first THX Certified HD products.
The THX II Certified Car Audio System can be found in many Lincoln automobiles produced since 2003. The system was recently recognized among the Best Car Audio Systems of 2006 by the editors of CNET.
THX Ltd. started a licensing program for home screening rooms in 2005, which requires standards similar in concept, though not in detail, to its cinema certification program; before this happened, there was a very small number of (very expensive) home theatres which were actually constructed to THX Cinema standards, most notable of actor and comedian Eddie Murphy.
The world's largest THX cinema is the Colosseum Kino in Oslo, Norway.
The distinctive crescendo used in the THX trailers is known as the "Deep Note."
The character in the THX trailers is called "Tex" and was created by John Lasseter at Pixar.
The THX trailer entitled "Cimarron", which first appeared at the start of the 1988 movie "Willow", used music composed by James Horner, while "Grand", which first appeared in theaters, featured a variation of the "Deep Note".
The THX Broadway logo on a DVD has a lower-pitched deep note, while the VHS/Laserdisc logo had a higher-pitched deep-note that was similar to "Wings" (1983).
The first theater THX was used in was at the University of Southern California's Eileen Norris Cinema Theatre as a part of USC's acclaimed film school. The Norris Theatre's THX system is currently second-best in California to that of the Grauman's Chinese Theatre.
Movie references.
Some trailers have references to, or are stylized to match, various movies and video games. Examples include: