This is from the review of Castaway on http://www.dvdangle.com:
There are three audio formats available on the DVD of Cast Away:
a Dolby Digital THX EX track and a DTS ES track, both of which
contain a matrixed center surround channel; as well as a Dolby
Digital 2.0 track for those without a home theater setup. As most
of you are aware, the full potential of the EX and ES tracks require
the use of a receiver or decoder specifically made for such, but not
to worry, either track can be decoded on standard DD/DTS equipment,
in which case the three surround channels are downmixed to standard 5.1,
in effect creating a "phantom" rear surround channel.
My question is, what are the "three surround channels"?
Front Center, Rear (Left) Center, Rear (Right) Center?