The DVD Skinny
Everybody wants to know about DVD lately. I keep getting
e-mail from our readers; why don't you write about DVD?,
they ask. That's easy--DVD is, at the moment, a video
format. The number of audio-only titles on DVD is minimal. SoundStage!
doesn't cover video issues, so we don't cover DVD, either. My
head isn't in the sand on this one, though. If you're in the
market to buy a new CD player, or a new laserdisc player, you
might very well be considering a DVD player instead. And if
you're not, maybe you should be. With that in mind, let's take a
quick run through the issues I see as being important things to
know before buying DVD right now:
- While it's not required by the DVD standard, all the
players being produced right now can decode regular audio
CDs. The DVD laser is similar enough to read both types.
Most DVD players can't read CD-R discs, whether they were
made on a computer or with an audio CD-R drive. The
Pioneer DVL-700 and Sony DVP-S7000 have
backward-compatible lenses that can also read CD-R, the
Toshiba SAD-3006 and Panasonic DVD-A300 don't. This isn't
an issue for most people, but it really gets me wound up
to discuss it.
- Pioneer makes DVD players that also can read laserdiscs.
Considering that DVD doesn't have too many movie titles
available, and that there are many laserdiscs that may
never be released on DVD, it may very well be worth the
extra money to get a DVD/LD combo player and stock on up
some laserdiscs now.
- DVD movies are usually mastered in Dolby Digital. Dolby
Digital was originally called AC-3, because that's the
encoding mechanism it uses. You'll need something to
decode that into the appropriate number of channels,
typically six. Most players have built-in DD decoders
that downmix the whole works into are two channel analog
output, sometimes in a Dolby Pro-Logic compatible format
(some only do a straight stereo conversion). You'll
obviously be losing something in the translation to
Pro-Logic if you use that output.
- The digital outputs on DVD players can either be coaxial
or TOSLINK. That doesn't mean you can hook them up to a
regular stereo DAC; the Dolby Digital AC-3 bitstream they
output by default is formatted differently. Some players
let you switch those outputs so they output in the older
format, which is called PCM audio. Depending on the
player, that switching can happen either via the remote
or with a physical switch on the back. On units with
multiple digital outs, you theoretically could have one
running through your stereo DAC while the other drives a
Dolby Digital decoder, if it supported the PCM/AC-3
switching for each individual output. I'm not aware of
such a player right now.
- Back when Dolby Digital was called AC-3, the only source
for it was a laserdisc player with a special RF output. A
RF demodulator was needed before the AC-3 decoder
transformed that into six channel playback. This is
totally different from the digital output on your typical
DVD player, even though the connector can look the same.
The Pioneer DVL-700 still requires that demodulator for
- Dolby Digital decoders are designed to be driven with the
digital output stream from a DVD player. Some also have
the older AC-3 RF decoder in them for use with
laserdiscs; if you're buying a Dolby Digital/AC-3 decoder
right now, make sure it can decode both formats if you
care about laserdisc.
- The built-in decoders in some DVD players (like the
Panasonic DVD-A300) actually decode into six analog
outputs, so you may not need a Dolby Digital Decoder.
Typically, these built-in decoders are underpowered
compared with the output decoder units, particular in the
area of bass management.
- Most early Dolby Digital/AC-3 material had all six
channels of output on it. Now that older movies are being
released, including mono classics like Blazing Saddles
and Caddyshack, some decoders that didn't quite
follow the spec closely enough and have never been tested
on mono material could choke on these discs.
- Receivers or preamps described as "Dolby Digital
Ready" typically have six analog inputs, for
discrete channels. The designation doesn't mean they have
a DD decoder in them.
- The higher video quality of DVD exceeds the quality of
normal NTSC video outputs (which are called composite
video). In order to get better resolution, you'll need to
have a TV with an S-video input instead While every DVD
player I know of has S-video outputs, some (the Sony DVP-
S7000 and Toshiba SD-3006) also have superior component
video capability. This is irrelevant unless you've got a
component video capable TV/monitor/projector, which are
rare and expensive. Expect them to become more available
now that DVD is here.
- The copy protection on some DVDs can screw up the signal
if you pass it through your VCR before it hits the TV.
- If you don't like the DVD picture, try turning the
sharpness down on the TV.
- There are differences between players in the quality of
the MPEG decoder and the video DACs used in DVD players.
Unless you're using component video with a really good
display, it's probably not worth the trouble of paying
extra for the best available video just yet.
Where do I see the market going? Let's look at the facts. VHS
tapes cost over $2 each to manufacture, while laserdiscs run
closer to $8. DVD disc costs are closer to $2 right now, but
should in short order drop to the approximately 50 cents that CDs
cost. Compared with VHS tapes, DVD doesn't degrade over time and
has overall better reliability. Compared with laserdisc, the
quality ranges from just as good to better, with the occasional
MPEG-2 artifact being insignificant from the perspective of
public acceptance. DVD is far easier to manage because you can
fit an entire movie on a disc; the public at large gets bad LP
mojo if they have to flip sides during any performance. Every
manufacturer of note is making players, and everybody big in the
video industry has signed up except Disney. Considering the
economics involved, the manufacturers have got to love DVD. I
expect market penetration to continue to rise, to the point where
DVD only imposes a slight price penalty over a regular CD player
or CD-ROM in your computer. The pricing is going to fall a lot
faster than CDs did when originally released, because the
manufacturing techniques involved are a lot closer to CD than the
CD techniques were to LP--going from one little digital format to
another is far less of a learning curve. There's still a battle
to finish with the audio industry before you can start buying all
your regular music on DVD, and expect that to take at least
another year to hash out. I don't see any reason why the video
side is going to change anytime soon, but if the price of a DVD
player represents a lot of money to you it's wise to wait at
least until Disney starts making discs--that will be a good sign
everything is going well with market acceptance.
As for me, the only units I see that's worth buying right now
are the Pioneer DVD players that also play laserdiscs and will
track my CD-R discs. If you've got different priorities, these
may not be the best choice for you. The information here should
help you get a good start shopping for DVD. For the really
in-depth scoop, read the DVD
FAQ or check out the listing of sources on our buddy Robert's
DVD Info page.