Dolby Digital 6.1 EX is an
enhancement to the standard Dolby Digital setup provided in most theatres. Concieved by Oscar-winning sound designer
Gary Rydstrom and with joint collaberation with THX and
Dolby Laboratories, the addition of a "back" channel to the theatre seemed a logical step in the evolution of theatre
digital sound.
Although Dolby 5.1 is a complete discrete 5 channel and LFE setup, Dolby 6.1EX is not. The additional "back" channel is derived from the matrixed components of the left and right surround channels.
Since DD6.1EX is a technology that is a subclass of DD5.1, then all DD6.1EX films are playable through a DD5.1 decoder.
Debuted in the latest chapter of the Star Wars series : Episode I, the new technology was also used in the following movies.
Buena Vista
Toy Story 2
Mission to Mars
Destination Films
Bats
DreamWorks SKG
The Haunting
Gladiator
Chicken Run
MGM/United Artists
James Bond: The World Is Not Enough®
New Line Cinema
Austin Powers: The Spy Who Shagged Me
Sony Releasing
The Messenger: The Joan of Arc Story
Twentieth Century Fox
The Fight Club
Star Wars, Episode One
X-MEN
Minority Report
USA Films
Pitch Black
Universal
The Bone Collector
The list of films using this was taken from the Dolby website. (quite some time ago, may I add.)