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Diffuse Sound.
In a movie theater, you’ll notice diffuse sound is created by using a large number of surround speakers (often
our Boston A70T professional theater speakers), placed high on theater walls, a sufficient distance from listen-
ers. Obviously, this is impossible in a normal living room. What makes truly diffuse sound a reality in the home
is a dipole surround speaker design.
Area of
Cancellation
When a conventional speaker is used for sur-
round, sound is aimed directly at the listener.
Because the listener can localize the sound, the
surround effect is spoiled.
The VRS figure-eight pattern emits frequencies
above 350 Hz away from the listener. This is
important because frequencies above this point
are easily localized by the human ear. The VRS
throws sound along the room’s walls. The sound
is, in turn, reflected by the walls, ceiling, floor,
and other surfaces before reaching your ears as
diffuse sound. The upshot: Sound comes from
all around you.
The term
dipole
refers to any two-sided object that emits waves (or absorbs them, in the case of microphones) in a
figure-eight pattern. In the VRS, this pattern is created by employing drivers that are “out of phase” with one another.
This means when one is pushing out, the other is pulling in. This results in two radiating patterns that cancel each
other out in the vicinity of the listener, creating a “null” space in the middle of the room.
