By Al Fasoldt
Copyright © 1990, The Syracuse Newspapers
I've heard surround-sound demonstrations for years, and they've
usually left me totally unimpressed.
So what if the sound track of a movie bounces around the room?
No matter how clever the recording engineer is, I'll never be
convinced that the good guys are in front of me and the bad guys
are behind me just because I can hear them firing their six-shooters
from behind my head.
Movies can't be realistic unless they pull a fast one on you.
They have to fool your eyes and ears.
That means they have to be viewed on a screen that's big enough
to fill most of your field of view, and it means the sound has
to seem like it's coming from the screen—more or less.
The first requirement can be met easily these days. Projection
TVs are getting better all the time, and the best of the new models
have amazingly sharp, bright pictures.
But it's the "more or less" part of the second requirement
that causes difficulty. If the sound doesn't seem to come from
the screen, your ears won't be fooled at all. Something inside
your brain sends out a message that says, "Hey, there's a
couple of loudspeakers behind your head, pal."
That's the wrong message when you want realism. You want your
brain to say, "Wow! Golly! Watch out! You'd better duck,
dude!"
So the only way to do that is to keep your ears from knowing what's
really going on. They have to hear just the front speakers in
the surround-sound system—but they have to sense what is coming
from the rear.
If the rear speakers are loud enough to be heard by themselves,
they get in the way and ruin the effect.
That's the mistake that many hi-fi and video stores make when
they set up demos of surround sound. And no doubt many listeners
repeat the mistake when they adjust their front and rear sound
levels at home.
So you can imagine that I was less than enthusiastic the other
day when my videophile brother invited me to watch one of the
"Indiana Jones" movies on his new home theater system.
He has a modern projection TV with a screen nearly 4 feet from
corner to corner. On each side are large loudspeakers with powerful
woofers. They can make walls shake a block away.
At the back of the room were two tiny speakers, so small that
they could have been the kind you plug into your Walkman. Were
they hi-fi? Well, maybe, but not the kind of hi-fi I was used
to. I like big sound; just ask my neighbors.
I sat in an easy chair toward the rear of the room. The TV came
to life and the movie began. The picture was big and vivid, and
the sound track—in stereo, of course—was stunning. It was
the best sound I'd ever heard outside a theater. (And it was better
than I'd heard in many old movie houses, too.)
Of course, I said to myself, this isn't surround sound, even though
there are two little speakers behind me. All the sound is coming
from the front.
But at my right, on a little table, was a surround-sound controller.
It was turned on.
The imp in me began hatching a plot. I waited until my brother
wasn't looking and then pushed the button marked "power"
on the controller. The little red LED next to the power switch
faded and died.
Suddenly the sound fell down. I'm not sure if I know how to explain
it any better. All of a sudden the sound was ordinary and flat.
It didn't come from the screen any more; it came from the two
loudspeakers at the front of the room.
My brother gave me an evil look. I smiled as if nothing had happened
and turned the little switch back on.
It took a half-second or so for the circuits to stabilize, and
then the room came back to life. The sound had width and height
and depth to it. And yet I still couldn't hear the speakers behind
me.
They were loud enough to supply the little cues that let my brain
know how "big" the sound was—how solid, you might
say—and yet they weren't loud enough to be heard by themselves.
It was a perfect demonstration. My brother even had popcorn and
soda. I was hooked.
As soon as I got home, I went shopping and picked up two of the
essentials, with only a few more items still needed.
I bought the popcorn and the soda. I already have a big TV, so
all that leaves is the surround-sound system.
Santa, I know this is a little bit early, but if you could swing
it, I'd like….
technofile:
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