Video Asylum

Posted by kotches (i) on August 25, 2000 at 07:21:11:

In Reply to: Confused about HT formats posted by NewtoHT on August 24, 2000 at 12:52:11:

Here's some of the answers for your question, hopefully this will
make things a little clearer for you than they are already.

Dolby Pro Logic:
Older matrix surround system, where the Center and Surrounds
are derived from information within the stereo left and right
channels. NOTE: The rear channels are mono...

Dolby Digital:
Also known as AC-3 (Audio Codec 3). This is a digital surround sound
with discrete channel configuration. The number of channels can range
from 2.0 all the way to 5.1, depending on the disk. Bit rates are
384 or 448 Kb/second. 6.1 variants are DD-EX (matrixed rear center)
and DD-EX Discrete.

DTS:
Digital Theater Systems. A digital surround format with discrete
channel configuration. The number of channels ranges from 4.0 to
5.1 with bit rates of 768 - 1536 Kb/second. 6.1 variants are
DTS-ES (matrixed rear center) and DTS-ES Discrete.

THX:
This isn't a surround sound format per se. Components that are
THX badged meet certain performance minimums and pay a fee to
LucasFilms LTD to put the badge on the component. THX components
aren't necessarily better than non-THX components. THX DVDs hmm.
Ok, I'm not sure what THX does on DVDs -- but I can't answer
literally EVERYTHING :-)

AC-3:
See Dolby Digital

Dolby 5.1:
See Dolby Digital

What is what?

See above.

Which one is the latest and greatest?
DD-EX Discrete and DTS-ES Discrete, although components supporting
those formats aren't even available yet.

Which one is the best format?
Lesser stuff than this has caused holy wars. My personal preference
when it's available is DTS.

Which one is the most popular format that movies come in?
Dolby Digital. It's also the standard used for surround sound
with HDTV.

If a movie is recorded in one format but my receiver plays another format, will there be degradation in quality or incompatibility issues?

This is actually pretty tricky... DTS decoding is on all but the
cheapest of receivers these days. DD is the current standard.
DD-EX and DTS-ES (matrixed or discrete) are supposed to be fully
backwards compatible with the regular variations. My recommendation
get an HT Receiver with DD and DTS (it'll also have pro-logic
capability) and you'll be safe.

I hope this helped you out some.