| Surround format | Number of
Channels | Types of channels | Type of media
the format can
be found on |
| Dolby Pro Logic | 4 | 2 discrete, full-bandwidth channels (front left and right); 1 matrixed, full-bandwidth channel (center); 1 matrixed, limited-bandwidth channel (surround left and right) | VHS movies, broadcast TV, can be downconverted from any Dolby Digital source |
| Dolby Pro Logic II | 5.1 | 2 discrete, full-bandwidth channels (front left and right); 3 matrixed, full-bandwidth channels (center, surround left and right); 1 subwoofer channel via Pro Logic II's bass management | all the same Dolby Surround sources as Pro Logic (VHS movies, broadcast TV), as well as stereo music |
| Dolby Digital | up to
5.1 | 5 discrete, full-bandwidth channels (front left and right, center, surround left and right); 1 discrete LFE channel (subwoofer) | all DVDs, some broadcast HDTV, and some DBS |
| DTS | 5.1 | 5 discrete, full-bandwidth channels (front left and right, center, surround left and right); 1 discrete LFE channel (subwoofer) | some DVDs and CDs (limited number specifically labeled with DTS encoded sound) |
| THX Surround EX | 6.1 | 5 discrete, full-bandwidth channels (front left and right, center, surround left and right); 1 matrixed, full-bandwidth channel (back surround); 1 discrete LFE channel (subwoofer) | a handful of DVDs are THX Surround EX-encoded; regular Dolby Digital 5.1 DVDs can also be used with a THX Surround EX decoder |
| DTS ES | 6.1 | 6 discrete, full-bandwidth channels (front left and right, center, surround left and right, and back surround); 1 discrete LFE channel (subwoofer) | a few DVDs |