Viking 25AE Design Manual page 3

Determining the Number and
Placement of Speakers
The Rule of Thumb Spacing Model
Sound coverage per speaker is directly related to
ceiling height. The taller the ceiling, the more the
sound spreads. Think of how a flood light mounted
higher up illuminates a larger area. The rule of
thumb model states that you place speakers apart
by twice the height of the ceiling. (See figures to
right)
For example, if you're working with 8' ceilings,
place speakers every 6 feet. In this example each
 speakers cover 56 square feet of ceiling (6 x
6).
Just like lighting, speakers perform best when they
are in the line-of-sight to the listener. Do not mount
speakers next to large beams or partial walls that
would obstruct the sound.
Consider the Reflection Issue
Reflected light is often softer and more pleasing
than light directly from the source. Unless, of
course, the light is being reflected off of glossy
surfaces, in which case it causes glare. The same
is true of sound. If your installation has hard floors
(vinyl, concrete, hardwood, etc.) and other "hard"
features such as metal benches, large industrial
equipment, etc., you have to be especially careful
to avoid "glare" or sound reflection. These surfaces
tend to distort sound, making pages unintelligible.
If the same application has high ceilings, planning
gets a bit more complicated because the listener
also hears reverberation.
The human aural system can easily integrate
sounds heard within 30 milliseconds of each other.
Reverberation causes more than a 30 millisecond
delay and the listener is bombarded with distortion
and "dual messaging."
In these applications you must modify the rule of
thumb spacing model and consider a minimum or
full overlap spacing pattern. (See next page)
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VIKING