THX is the trade name of a high-fidelity sound reproduction system for movie theatres,home theaters,computer speakers,gaming consoles,and car audio systems.THX was developed by Tomlinson Holman at Lucasfilm in 1983 to ensure that the soundtrack for the third Star Wars film.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 digital (Dolby Digital,SDDS) and all analog sound formats (Dolby SR,Ultra-Stereo) can be "shown in THX."THX is mainly a quality assurance system.If a producer has their film mixed in THX,it merely means that when the film is shown in theaters,the soundtrack will sound exactly as it did when it was mixed,if the theatres are THX-certified.