JBL Control 23 Owner's Manual page 11

It is important to understand that just as the propagation of sound
outdoors is effected by its surroundings so is the propagation of sound
indoors. Some of these environmental factors exist in both cases,
such as reflective surfaces and absorbant materials, but there are a
few unique effects that may need to be considered. The factors
described on this page can cause the behavior of an outdoor installa-
tion to deviate from the Inverse Square Law. Remember not all
frequencies of the propagated sound will be affected uniformly.
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• Humidity- Because water vapor is lighter than air, humid air .
is less dense than dry air and, therefore absorbs less
acoustical energy than dry air particularly at frequencies
above 2kHz. To labour the point, a speaker mounted on a
tree in a jungle will project high frequency sound further than
the same speaker mounted on a cactus in the desert (see
diags. 5 & 6).
Painting the Speakers-
The polystyrene speaker enclosures of the Control® 23,
Control® 25, & Control® 28 can be painted to match almost
any decor. The vinyl skin of the Control® SB-2 subwoofer can
also be painted.
• Remove the grilles. Mask the woofers, tweeters, & ports on
the front, and the wire terminals on the back, being careful
that no tape comes in direct contact with the drivers.
• Clean the enclosures with a light solvent such as mineral
spirits by rubbing the components with a lightly dampened
cloth. Do not, however, use abrasives such as sandpaper or
steel wool on the enclosures. Nor should you use gasoline,
kerosene, acetone,
MEK,
paint thinner, harsh detergents or
other chemicals. Use of these cleaners may result in perma-
nent damage to the enclosures.
• After cleaning, apply two or more thin coats of either latex or
oil-based paints. Latex paints will adhere better if an oil-
based primer is used first. Application can be by rolling,
brushing, or spraying.
•The grilles require masking of the logo plug, then spray
painting. If the grill is rolled or brush painted, the mesh may
become clogged with paint, and poor sound quality may
result.
• The /nvisiBalfM mount may also be painted, but because it
is metal, latex paints will not adhere as well as other finishes.
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