Smart Home Lifestyle
April 2, 2006
Breaking the DVD audio code: a primer
Which came first, the story line, or the sound effects? In my
business, it’s all about “feeling” the action, which
pretty much boils down to a 7.1 surround system, a subwoofer and a Star
Wars DVD. But great sound isn’t exclusive to a George Lucas
movie; just about every DVD these days has the right “stuff” for
a movie theater experience at home.
Why Surround Sound?
When Lucas said that the secret to film is that it’s an illusion,
he must have been thinking about surround sound. Upgrading from
a standard two-channel system to a 5.1 surround sound system, or better,
puts you in the center of the action. Now you can hear the airplane
flying from right to left, and that glass breaking behind you. It’s
no longer just your imagination.
Is it point one or dot one?
There are several speaker placement
options, with 5.1 and 7.1 most
commonly seen. In a surround system,
the first number represents the number of surround speakers, and the
.1 always refers to the subwoofer. So, in a 5.1 system you’ll
have six total speakers. For the left and right front speaker
I recommend tower speakers,
since most of the music and sound will come from these.
When it comes to your center speaker, never scrimp on size or quality. Remember,
all the dialogue now comes from the center speaker and not your TV speakers,
so in this case, bigger is definitely better. The remaining speakers
include the surround speakers, which are normally bookshelf size, and
a subwoofer. The subwoofer can be placed anywhere in the room,
unlike the rest which have specific designations for the best quality
sound.
The only difference between 5.1, 6.1 and 7.1 is the addition of extra
speakers in the back. But don’t forget to plan accordingly
when it comes time to buy a receiver. If you’ve got a 7.1
surround system, make sure and buy a 7.1 surround receiver, not a 5.1
or a two-channel receiver.
Yeah, but what do all those “D” words mean?
The back of every DVD lists the audio format used. Before you
even pick up the DVD, make sure it’s in widescreen format, then
check for 5.1surround sound. You’ll likely see one of two
formats, Digital Theater System (DTS) or Dolby Digital, the most common
of the two. Dolby Digital comes pretty standard these days, and
is even seen with many of the re-mastered movies and TV show re-releases
like the 80’s show “Miami Vice.”
Digital Theater System (DTS)
Jurassic Park was the first full-scale
movie to use DTS, although
these days you hardly see the DTS format on new release DVDs. DTS
is seen with both DVD-video and DVD-audio, for music-only surround sound.
While DTS is not as common, it does provide a higher bit rate than Dolby
Digital, and is the subject of an ongoing argument over better the better
format.
Dolby Digital
Like DTS, Dolby Digital uses six tracks for a 5.1 surround system. Basically,
there are six discrete audio channels that get sent to the appropriate
speaker to achieve the necessary effect or sound in the right spot.
And to make things even more confusing, if you see Dolby EX on the
case, the discrete channels are bumped up from six to seven, for a 6.1
surround system. It’s the same with DTS, except you’ll
see DTS ES, not DTS EX.
So, what is THX?
THX is an equipment certification defined by George Lucas’ requirements. This
rating ensures the highest level of quality in both sound and picture
for DVD players, receivers, preamplifiers, power amplifiers, speakers
and even cables. If you see THX stamped on your electronics, it’s
a safe bet that it’s a winner.
Author: Diana Kostigen, Marketing/Public Relations Director, Comtec
