Wilson Electronics Grand Slamm, Owner'S Manual, Page: 14 / 80

W I L S O N A U D I O S P E C I A L T I E S , I N C .
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ECTION
1.1 R
OOM
R
EFLECTIONS
There are 3 commonly encountered room reflection problems: slap echoʼs, standing-
waves, and comb filter effect.
S
LAP ECHO
Probably the most obnoxious form of reflection is called “slap echo.” With slap echo, primarily mid-
range and high frequency sounds reflect off of two parallel hard surfaces. The sound literally reverberates
back and forth until it is finally dissipated over time. You can test for slap echo in any room by clapping
your hands sharply in the middle of the room and listening for the characteristic sound of the echo in the
mid-range. Slap echo destroys the sound quality of a stereo system in two ways:
§ It adds harshness to the upper mid-range and treble through energy time storage.
§ It destroys the delicate phase relationships, which help to establish an accurate sound stage.
Slap echo is a common acoustical problem in the typical domestic listening room because most of
these rooms have walls with a hard, reflective nature, usually being only occasionally interrupted by curtains
or drapes. The best solution to eliminate slap echo is non-parallel walls, this is because non-parallel walls do
not support slap echo, but rather allow the sound to diffuse. Otherwise, slap echo can be controlled entirely
by the application of absorptive materials to the hard surfaces, such as:
§ Sonex
§ Airduct board
§ Cork panels to the hard surfaces.
§ Large ceiling to floor drapes
§ Carpeting to wall surfaces.
In many domestic listening environments, heavy stuffed furnishings are the primary structural con-
trol to slap echo. Unfortunately, their effectiveness is not predictable. Diffusers are
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