Whats the difference between Dolby Surround, Dolby Pro Logic and Dolby Digital?
These are all encoding techniques to allow a multichannel signal to be delivered to the consumer. The main difference between them is the number of channels and how the signal is decoded. While Dolby Surround and Pro Logic are closely related (with the main difference being the fact that Surround uses a passive decoder while Pro Logic uses an active one), Dolby Digital is a completely different, more sophisticated technique and not compatible with the others.