Summary of surround sound systems:
Dolby Pro Logic matrix decoder, an analog surround sound system, decodes surround
information from stereo sound, if present (4 channels). Result: left and right, center,
2 mono rear channels (100Hz - 7,000Hz).
Dolby Pro Logic II matrix decoder, an analog surround sound
system, decodes surround information from stereo sound, if present (5
channels). Result: left and right, center,
2 stereo rear channels (full range surround channels), subwoofer channel (10 Hz-120 Hz).
Dolby Pro Logic IIx an analog surround sound system, transforms stereo audio into 5.1 or 7.1 channel surround sound system.
Dolby Digital 5.1 dolby digital decoder, a digital surround sound system, 6
separated channels:
3 front (left, center, right), 2 back, 1 subwoofer (.1: LFE = Low-Frequency Effects channel;
10 Hz-120 Hz).
Dolby Digital 6.1 a digital surround sound system, 7
channels: 3 front (left, center, right), 3 back (left, center,
right), 1 subwoofer.
Dolby Digital 7.1 a digital surround sound system, 8
channels: 3 front, 4 back (left, center, center, right), 1
subwoofer.
Dolby Digital Surround EX a digital surround sound system, a 5.1 channel format with
an extra back surround audio channel matrixed.
DTS a digital surround sound system, another 5.1 channel sound system, gives more quality,
6 separated channels: 3 front (left, center, right), 2 back, 1 subwoofer (10 Hz-120
Hz)
DTS-ES a digital surround sound system, extends the 5.1 channel surround sound format with one (or two)
additional speaker(s) located in the back.
DTS-ES Matrix a digital surround sound system, a 5.1 channel format with
an extra back surround audio channel matrixed.
DTS-ES Discrete 6.1 a digital surround sound system, true 6.1 channel format
(7 channels).
DTS-NEO:6 an analog surround sound system, DTS's version of Pro Logic II.
ICE transforms stereo audio into 5.1 or 7.1 channel surround sound system.
SDDS Sony Dynamique Digital Surround, not used in home systems.
SRS TruBass enhances the bass impact when you have small speakers.
THX this is not a sound format, but a quality label.
