Does 5.1-channel Dolby Digital make Dolby Surround obsolete?
No. Dolby Surround will continue to be a preferred method for delivering surround encoded content within the space of a stereo signal. This is why all Dolby Digital decoder units also incorporate a digitally implemented Dolby Surround Pro Logic® decoder. Programs encoded in Dolby Surround can be played back in mono, stereo, or with a Dolby Surround Pro Logic decoder that recovers the four original channels. These programs can also be played in Dolby Pro Logic II for five independent full-range channels.
No, Dolby Surround will be with us for as long as stereo is with us. This is why all Dolby Digital decoder units also incorporate a digitally-implemented Dolby Surround Pro Logic decoder. Dolby Surround encodes four sound channels (left, center, right, surround) onto the two tracks of any conventional stereo program source. Dolby Digital soundtracks, on the other hand, can be carried only by Laserdiscs and new formats such as DVD and DTV. Dolby Surround-encoded programs can be played back in mono, stereo, or with a Dolby Surround Pro Logic decoder that recovers the four original channels. Dolby Surround sources include regularly-scheduled TV programs (over a hundred in the U.S.), plus sports and special events; a growing number of video games, CD-ROMs, and music CDs; and broadcasts, tapes, and discs of thousands of movies.
