THX

THX is a high-fidelity audio/visual reproduction standard for movie theaters, screening rooms, home theaters, computer speakers, gaming consoles, and car audio systems. The current THX was created in 2002, when it spun off from Lucasfilm; THX was developed in 1983 by Tomlinson Holman at George Lucas's company Lucasfilm to ensure that the soundtrack for the third Star Wars film, Star Wars Episode VI: Return of the Jedi, would be accurately reproduced in the best venues. THX was named after Holman, with the "X" standing for crossover as well as an homage to Lucas's first film, THX 1138. The distinctive crescendo used in the THX trailers, created by Holman's co-worker James A. Moorer, is known as the "Deep Note".

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, etc.) or analog (Dolby Stereo, Ultra-Stereo, etc.), 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 film 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 audio crossover circuit whose use is part of the standard. Certification of an auditorium entails specific acoustic and other technical requirements; architectural requirements include acoustically-treated walls, no parallel walls to reduce standing wave, a perforated screen to allow continuity and rating for background noise.

THX is currently owned by Audio Equipment Manufacturer Razer, Inc.