By Al Fasoldt
Copyright © 1993, The Syracuse Newspapers
Four-channel sound used to be a joke.
Back in the '70s, JVC of Japan and our own CBS Records tried to
convince millions of music lovers that we could get four separate
sound sources out of a long-playing record.
They were right; we got four separate
sound sources, and they all sounded terrible. Their slogan should
have been, "Bad Sound All Around." Luckily, four-channel
sound quickly disappeared into the junkyard of audio history.
But now it's back again, under a new name—"surround
sound." And this time, the electronics engineers have done
the job right.
In a more primitive form, surround
sound has been around for quite a few years. This kind of surround
sound used a circuit developed by the Dolby company—the same
outfit that came up with the universal method of getting the hiss
out of cassette tapes.
I've had a Dolby surround-sound adaptor
hooked up to my video-theater hi-fi system for two or three years,
and it's done a pretty good job. When I watch a movie, many of
the sound effects come right out of the back of the room.
But while the standard Dolby surround-sound
system can provide some exciting effects, they aren't very realistic.
There are technical reasons for this, but the main point is that
true surround sound should be exactly that—sound that surrounds
you. Regular Dolby surround-sound circuitry gives you a ping-pong
effect—first you hear something from the front, then the back,
then the front again.
That's not the way it is in real
life, unless, of course, you're watching a table-tennis match.
So Dolby's engineers came up with
a new version called Dolby Pro Logic. It's a smart device, recreating
the sound-all-around sensation that you get when you are in the
middle of all the action. Dolby Pro Logic can only do its job
properly when the videotapes and laser discs you rent or buy have
sound tracks encoded with Pro Logic signals, but this is becoming
fairly common.
What's more, even standard stereo
TV broadcasts sometimes have Pro Logic encoding. And as a bonus,
I've even heard a few compact discs that have the same surround
sound built in, too.
For the last month or so I've been
listening to Dolby Pro Logic audio through a new audio-video receiver
loaned by the Carver Corp. It's the Carver HR-895, which has four
stunning features besides Dolby Pro Logic. They are Sonic Holography
(a way of improving the realism of the sound over some kinds of
speakers), a center-channel audio signal, a vastly improved FM
tuner circuit that let me pull in stations more than 80 miles
away, and two remote controls—a regular one with a zillion
buttons and a credit-card-size remote with just the basic controls.
The HR-895 has only one drawback—the price.
It lists for a whopping $1,600. It's not hard to
see where part of that megabuck cost goes, since the Carver has
four powerful amplifiers and a sophisticated switching system
that lets you record on one VCR while you are watching a tape
from another one, but a receiver that costs as much as eight typical
CD players is plainly out of the reach of most of us.
On the other hand, if you have not
yet purchased a hi-fi system and can afford the price of entry,
the Carver HR-895 would make an excellent combination unit. It
has all the functions of an amplifier, tuner, control center,
audio-video switching box and surround-sound adaptor—and does
it all without a fuss.
The sound quality from regular hi-fi
sources is first-rate, especially when the Sonic Holography circuit
is switched in, but it's the Dolby Pro Logic that captivates me
every time I turn this big receiver on. The latest video movies
recorded with Pro Logic pass my "blind listening" test
easily—the soundtracks still seem realistic even when I close
my eyes. Try that with regular movie soundtracks, and you'll probably
find the sound falls flat without visual cues.
technofile:
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