Smokey
05-03-2004, 02:49 PM
A Summary of Available Formats:
Dolby Pro Logic:..................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-pl.jpg">
This is a Matrix* decoder delivering 4 output channels, Left / Center / Right / Surround. Virtually every movie since 1977 has had a two-channel soundtrack with Center and Surround folded in.
Note: A subwoofer signal can always be derived through bass management, but it is not technically part of the matrix decode scheme.
Dolby Digital:.....................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dd51.jpg">
Dolby Digital is a flexible discrete** digital technology for carrying audio. It is most often thought of as "5.1", though it must be noted that it can have just about any combination, including 1.0, 2.0, 4.0, 4.1, and 5.1 etc. In the case of 2.0, where it is basically a two channel carrier, Dolby Pro Logic may be applied to get 4 output channels. Just about every movie since 1991 has had a Dolby Digital 5.1 soundtrack while every DVD in the world must include either some form of Dolby Digital sound (or Linear PCM).
DTS:.............................................. ..<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dd51.jpg">
This is also a discrete** audio carrier technology, delivering either 5.0 (in the commercial cinema system) or 5.1 (in the consumer system). Not every Hollywood movie gets circulated with a DTS soundtrack, and DVDs including this optional format are a minority.
THX Surround EX / Dolby Digital EX:.....<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-ddex.jpg">
Jointly developed by THX and Dolby, this playback system first appeared in the consumer market only on THX equipment as THX Surround EX but later came to be known as Dolby Digital EX on non-THX equipment. This system is a "marrying" of discrete and matrix technology. In a nutshell, a Dolby Digital 5.1 soundtrack is the source.
The Pro Logic matrix* decoding technology is used on the two surround channels, turning them into three: Left Surround, Center Surround, and Right Surround. While it can rightfully be said this system is intended for a 6.1 playback layout, THX and Dolby have avoided calling it a 6.1 delivery system as that would imply it is a discrete format, which it honestly is not. As of this writing there have been 34 titles made in EX, virtually all including it when released on DVD.
Note: Although it is possible to use one speaker in the center surround position, THX has always advocated, or set a preference for, using two speakers for that one channel.
DTS ES:.....................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-ddex.jpg">
This is the same principal as Dolby Digital EX, and in fact the same source track as a Dolby Digital EX soundtrack, only at decode time it uses DTS's own matrix technology to derive the trio of surround channels.
DTS ES Discrete:..........................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dtsdis.jpg">
This is the same layout as Dolby Digital EX / DTS ES, except that the sixth main channel is actually discrete with its own carrier channel at the source. This system may honestly be referred to as "6.1". There have been no Hollywood movies circulated with this type of soundtrack (it has never been used in the commercial systems), and precious few DVDs include a soundtrack remixed for DTS ES Discrete.
Dolby Pro Logic:..................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-pl.jpg">
This is a Matrix* decoder delivering 4 output channels, Left / Center / Right / Surround. Virtually every movie since 1977 has had a two-channel soundtrack with Center and Surround folded in.
Note: A subwoofer signal can always be derived through bass management, but it is not technically part of the matrix decode scheme.
Dolby Digital:.....................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dd51.jpg">
Dolby Digital is a flexible discrete** digital technology for carrying audio. It is most often thought of as "5.1", though it must be noted that it can have just about any combination, including 1.0, 2.0, 4.0, 4.1, and 5.1 etc. In the case of 2.0, where it is basically a two channel carrier, Dolby Pro Logic may be applied to get 4 output channels. Just about every movie since 1991 has had a Dolby Digital 5.1 soundtrack while every DVD in the world must include either some form of Dolby Digital sound (or Linear PCM).
DTS:.............................................. ..<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dd51.jpg">
This is also a discrete** audio carrier technology, delivering either 5.0 (in the commercial cinema system) or 5.1 (in the consumer system). Not every Hollywood movie gets circulated with a DTS soundtrack, and DVDs including this optional format are a minority.
THX Surround EX / Dolby Digital EX:.....<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-ddex.jpg">
Jointly developed by THX and Dolby, this playback system first appeared in the consumer market only on THX equipment as THX Surround EX but later came to be known as Dolby Digital EX on non-THX equipment. This system is a "marrying" of discrete and matrix technology. In a nutshell, a Dolby Digital 5.1 soundtrack is the source.
The Pro Logic matrix* decoding technology is used on the two surround channels, turning them into three: Left Surround, Center Surround, and Right Surround. While it can rightfully be said this system is intended for a 6.1 playback layout, THX and Dolby have avoided calling it a 6.1 delivery system as that would imply it is a discrete format, which it honestly is not. As of this writing there have been 34 titles made in EX, virtually all including it when released on DVD.
Note: Although it is possible to use one speaker in the center surround position, THX has always advocated, or set a preference for, using two speakers for that one channel.
DTS ES:.....................................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-ddex.jpg">
This is the same principal as Dolby Digital EX, and in fact the same source track as a Dolby Digital EX soundtrack, only at decode time it uses DTS's own matrix technology to derive the trio of surround channels.
DTS ES Discrete:..........................<img src="http://www.hometheaterhifi.com/volume_11_1/images/layout-dtsdis.jpg">
This is the same layout as Dolby Digital EX / DTS ES, except that the sixth main channel is actually discrete with its own carrier channel at the source. This system may honestly be referred to as "6.1". There have been no Hollywood movies circulated with this type of soundtrack (it has never been used in the commercial systems), and precious few DVDs include a soundtrack remixed for DTS ES Discrete.