Owner manual

Nonparallel walls do not support slap echo, but rather allow the sound to diffuse.
Slap echo is a common acoustical problem in the typical domestic listening room, be-
cause most of these rooms have walls of a hard, reflective nature, usually being only oc-
casionally interrupted by curtains or drapes. Slap echo can be controlled entirely by the
application of absorptive materials to hard surfaces, such as:
• Sonex
• Airduct board
• Cork panels
• Large ceiling to floor drapes
• Carpeting to wall surfaces
In many domestic listening environments, heavy stuffed furnishings are the primary
structural control to slap echo. Unfortunately, their effectiveness is not predictable. Dif-
fusers are sometimes also used to very good subjective effect, particularly in quite large
rooms. Sound absorbent materials such as described above will alter the tonal charac-
teristic of the room by making it sound “deader, much heavier in bass tonal balance, less
“bright and alive” and “quieter.” These changes usually make the room more pleasant
for conversation, but sometimes render it too dull in the high frequencies to be musical-
ly involving. Diffusers, on the other hand, tend to not change the high frequency tonal
balance characteristic of the room, but make the sound more “open”. A combination of
absorbtive and diffusive treatments is usually the best approach.
STANDING WAVES
Another type of reflection phenomenon is standing waves. Standing waves cause
the unnatural boosting of certain frequencies, typically in the bass, at certain discreet lo-
cations in the room. A room generating severe standing waves will tend to make a loud-
speaker sound one way when placed in one location and entirely different when placed
in another. The effects of standing waves on a loudspeaker’s performance are primarily,
as follows:
• Tonal balance-Bass too heavy
• Low-level detail- Masked by long reveration time LF standing
waves
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C U B O W N E R ʼ S M A N U A L