There are no Dolby or DTS 7.1 formats.
The DTS-ES Discrete 6.1 format actually delivers a discrete rear center channel.
Dolby Digital EX Matrix 6.1 and DTS-ES Matrix 6.1 both encode the rear channels in a manner similar to Dolby Pro Logic so that a rear center channel can be derived.
P.S. If you haven't heard about the Chesky 6.0 format, you should take a look at the following website:
http://www.enjoythemusic.com/magazine/manufacture/chesky.htm
The DTS-ES Discrete 6.1 format actually delivers a discrete rear center channel.
Dolby Digital EX Matrix 6.1 and DTS-ES Matrix 6.1 both encode the rear channels in a manner similar to Dolby Pro Logic so that a rear center channel can be derived.
P.S. If you haven't heard about the Chesky 6.0 format, you should take a look at the following website:
http://www.enjoythemusic.com/magazine/manufacture/chesky.htm