Introduction|
Mono|
Dolby Stereo|
Dolby Surround|
Dolby Digital Surround-EX
The extra channel is intended to be heard through at least two additional speakers
located on the rear wall, while the existing surround-left and surround-right
speakers are moved to the sides. Movie theatres, because of their size, use
several speakers on the walls all around the room. The home cinema versions
of this format are known as THX Surround-EX, with the discrete and matrix
versions available in both THX-Select and THX-Ultra hardware.
Dolby Pro-Logic|
Dolby Pro-Logic II|
Dolby Digital|
Dolby Digital Surround-EX|
DTS|
DTS-ES|
THX|
Sony SDDS|
The latest version of Dolby Digital is Surround-EX . Jointly developed by Dolby
Laboratories and Lucasfilm THX, the EX format made its theatre debut in 1999
with the release of Star Wars Episode 1 - The Phantom Menace. The EX format
adds a rear-centre audio channel, known as 'surround-back' matrixed within the
normal Dolby Digital 5.1 soundtrack. Using non-EX decoding, the sound is
presented as Dolby Digital 5.1, while an EX equipped decoder will separate
the hidden rear channel in the same way that a Dolby Pro-Logic decoder separates
the centre channel from a stereo Dolby Surround recording.
