THX (Tomlinson Holman Experiments): Test certificate for cinemas developed by Tomlinson Holman, former chief technician at Lucasfilm, which includes the quality of the acoustics, the hardware equipment and the screen.
In order to achieve optimal playback quality in home cinema, too, Lucasfilm has expanded the list of requirements to include devices and software for home cinema. This catalog mainly includes specifications for decoder functions, power amplifier performance and speaker settings. THX now differentiates between the more demanding THX Ultra version for large home theaters and the weaker one THX Select- Variant for normal living room.