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YOUR SOUND SYSTEM: SETTING IT UP TO
GET THE BEST RESULTS
Before we talk about setting up your
sound system. let's talk a bit about what you have to
work with.
The amplifier is the heart of the sound system. The music
source (phonograph, Laptop, MP3 player, tape, MiniDisc or CD player)
generates a feeble electrical current. The diaphragm of
the microphone is vibrated by the sound waves of your
voice and it also generates a feeble electrical signal.
Because they change energy from one form to another they
are called transducers. Feel free to use that word any
time you want to impress somebody. The amplifier picks up
these feeble signals, makes them much stronger, and
delivers them to the third transducer in the system, the
loudspeaker, which changes the electrical energy back to
sound energy again. Unfortunately, it changes only part
of the electrical energy to sound; the rest is changed to
another form--heat.
When you turn up the music volume control on your
amplifier, the music will get louder until you reach a
certain point. At that point it begins to get distorted,
and the more you turn the knob, the more distorted it
will be. You have reached the maximum undistorted output
of your amplifier. From that point on, you will get very
little more volume and much more distortion. Lesson
number one: It is useless to turn up the knobs as far as
they will go.
The speaker, as we said, changes electrical energy into
sound. The two factors that limit the amount of sound a
speaker will produce are its power handling capacity and
its efficiency. Every speaker has a point at which
applying more amplifier power will not produce any more
sound; it just produces distortion which gets worse as
more power is applied. This is called overloading, and
too much overload can actually damage a speaker. It is
quite possible that you could unhook that speaker and
plug in another that would produce much more sound,
without touching the volume control! The second speaker
is more efficient than the first. More energy is turned
into sound and less onto heat.
The amount of power that the amplifier delivers is
measured in watts. Let's say that you have an amplifier
that will deliver 25 watts without distortion, and a
speaker that will handle 50 watts without overloading. If
only you had a 50 watt amplifier, you could get twice as
much sound from that speaker, right? Wrong. To double the
sound level from a speaker requires ten times as much
power from the amplifier. If you apply twice as much
power you will get more sound, but nowhere near twice as
much. That's lesson number two.
If you use two speakers instead of one you ought to get
twice as much sound, right?. Wrong again. The maximum
undistorted output limitation still applies. You will get
more sound at the same control knob settings, because you
have lowered the impedance. That's another impressive
word, which we put in to convince any experts that we
know what we're talking about. But anyhow, your amplifier
has only so much undistorted output, and dividing it
between two speakers isn't going to get you twice as much
sound. What you can get, if you set up your speakers
correctly, is much better sound distribution. That's
lesson number three.
Better sound distribution may well enable you to cover
twice as much area as you could with a single speaker.
With a single speaker you often have to waste part of
your amplifier output by making the sound too loud in the
front in order to get it loud enough at the back and
sides of the hall.
In setting up your equipment, the most important
consideration is where you locate and aim your speakers.
A speaker sitting on a stage will cover only a fairly
small area of the floor. If you raise it up a few feet,
it will probably cover twice as much area with better
sound. That's rule number one. Aiming your speakers at
the dancers, not at the opposite wall, is rule number
two. The sound must pass over the heads of the nearest
dancers and reach the farthest dancers without bouncing
off the opposite wall. If you can't cover the entire hall
with the sound system you have, mark off the area you can
cover with chairs or tables so the dancers stay within
that area.
Square shaped hall:
One speaker: Place it at the midpoint of one wall: If the
sound drops off too much at the sides, try placing it in
a corner and see if you can reach the opposite corner
with sound. If your speaker is of the open back type, try
to place it against a wall. Just as much sound comes out
of the back as from the front; if it is against a wall
the reflected sound will reinforce the sound on the
floor, and if it is very far out from a wall you lose
efficiency and may well create an echo. Two speakers:
Divide the area in half and use one speaker to cover each
half.
Rectangular shaped hall: (length less
than twice the width)
A consideration here is that different types of speakers
have varying angles of lateral dispersion--the angle at
which the sound fans out to the right and the left.
Speakers with wide angles of dispersion ordinarily won't
cover nearly as far straight ahead as those with
narrower, more intense beam of sound.
One speaker: Try setting up at the midpoint of one
(narrow) end. If you can't reach the other end, set up at
one (wide) side and aim across the shorter dimension. The
sound may be thin at the ends, but should be good in the
central position of the hall.
Two speakers: In most cases driving across the shorter
dimension gives best results. Place speakers so that each
covers half the area.
Long, narrow hall:
One speaker: Set up at one (narrow) end. The higher you
get your speaker the farther it will reach; if it won't
reach the other end, it won't.
Two speakers: If the ceiling is so low that you can't set
up at one end and reach the other end, use a long cord
and place one speaker at each end of the hall, aimed at
each other. Tilt both speakers down at the heads of the
dancers at the center of the hall. This will give good
sound with no "time lag effect" which would
distort the sound at the center. Never set up one speaker
at the end and another partway down the hall aimed the
same direction as the first. Without sophisticated time
delay devices such a setup will have the affect of
creating an echo in the back of the hall; this is the
same problem caused by excessive reverberation.
Outdoor setups:
These require much more power because there is no sound
reinforcement from reflected sound. Aim speakers at trees
and shrubbery if possible, never at a flat wall or you
will really have an echo. One or two additional speakers
are often require outside to keep the coverage even as
well as the extra power to push them.
Follow our bird to the next topic
TO RETURN TO THE
"SOUND" INFORMATION T. O. C. CLICK HERE
 Contact
Information
For a complete information package contact Dick
Henschel at:
HILTON AUDIO
PRODUCTS, INC.
1033-E Shary Circle, Concord, California 94518
Phone: 925-682-8390 - Fax: 925-682-8497 - E-mail: hiltonaud@aol.com
Copyright
© 2007 - Hilton Audio Products, Inc.
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