Home Theater Systems
Why You Need More Than Two Loudspeakers
real life, our ears and brain interpret sounds from every direction,
in a 360-degree circle, including even the dimension of height.
Like a super computer running in high gear, our sophisticated hearing
system decodes spatial and directional information in real time,
telling us instantly the tonality, frequency content, and loudness
of sounds from all directions.
stereo, on the other hand, uses just two speakers at the front left
and right, to try and simulate the complex directional and spatial
information that we hear in real life. It does a decent job of reproducing
a musical event, even fairly impressive at times. But it is limited
to those two boxes up front, and two directions, give or take a
bit. Even as early as the 1930s, Bell Telephone scientists concluded
that a minimum of three channels were necessary to convey a reasonable
simulation of an orchestral performance--two channels at the
left and right, and one in the middle.
the late 1950s and '60s, Hollywood sound engineers realized that
more channels of sound were better, and added magnetic stripes to
the edge of epic 70mm widescreen movies, which delivered up to six
separate "tracks" or sound channels. Audiences loved the
effect: Multiple channels more closely approximated the multidirectional
sounds our ears pick up in everyday life. There was a center
channel behind the screen for the actor's dialogue; left and right
front speakers for the music, and eventually, left and right surround
speakers on each side of the movie theater for ambient sounds-the
wind in the trees, crickets in summer, and the howling of wolves.
back then, home audio technology wasn't up to the task of duplicating
these events in our living room. Now it is, and it's called "Home
Theater"! First came Dolby Surround, with four channels, in
the 1980s, and now we have Dolby Digital 5.1-channel sound on virtually
every movie issued on DVD. That's six separate or "discrete"
channels of sound: left and right front main channels (like
stereo), a dedicated center channel speaker for dialogue to
anchor the actor's voices at the TV screen no matter where you're
sitting, two left and right surround speakers at the sides
of your listening area for all those ambient environment sounds,
and a sixth deep bass subwoofer channel-it's the ".1"
in 5.1--which contributes the shakes and shudders of thunder, explosions,
and powerful musical bass effects. If you've kept count, that's
a total of five "satellite" speakers--plus one subwoofer
for ultra-low bass. Now you see why we need six speakers. And those
engineers are working on one more, for height!
you know what it is . . . so what do you need? Click here
to send an email to our audio experts for a recommendation based
on your room size and listening preferences, or contact us toll-free
at 1-888-352-9466 for fast, free, friendly advice. Or, try the
Theater Wizard , our automated recommendation tool.
Theater Basics: Buying A DVD Player
Theater Basics: Home Theater Components