Niles Audio PSW8 - Manual (Page 10)

Treatment & Placement
Typically, sheetrock encloses the sub-
woofer in most installations. Sheetrock has
a fairly loud resonant “twang” compared
to the rigid non-resonant enclosures of
most floor standing subwoofers. None of
the following modifications are absolutely
necessary, however any one or combina-
tion of them will improve the performance
of the subwoofer.
Minimum Enclosure Size
The PSW8 will produce magnificent
results if the wall cavity behind the
woofer is a minimum of 1900 cubic inch-
es. If the wall studs center measure 4”
deep (2x4) and are spaced 14-1/4” apart
(16” spacing) you would want the length
of the air cavity to be a minimum of 33-
1/3”. A larger cavity is fine.
Insulation
Lay a batten of fiberglass insulation (e.g. R-19
un-batted insulation) behind of the speaker.
If you have more than one subwoofer in the
room, place the same amount of insulation
behind each subwoofer. If your enclosure is
smaller than the recommended 1900 cubic
inches, try packing more insulation into the
space behind the speaker. This effectively
increases the enclosure size.
Enclosure Bracing
Insert small pieces of 1x2 or 1x1 scrap
wood as wedges between the front and
back panels of sheetrock if possible. Do
not use too long of a piece as you could
create a bulge in the wall surface.
Enclosure Lining
Purchase some subwoofer damping materi-
al from a car stereo store (there are various
brands available, e.g. Dynamat
™ ). Apply
the damping material to the back of the
wall behind the PSW8 and to the
sheetrock surrounding the wall beside the
subwoofer.
Speaker Placement Techniques
Although the PSW8 has extensive ability to
compensate for unusual placements with its
crossover switches; placement is still the
primary tool for satisfying your particular
listening needs.
Maximizing Output
The Boundary Effect – Placing your sub-
woofer near the floor or in a corner will
increase the volume of bass sound pro-
duced by the subwoofer! This is called the
boundary effect. Generally, you can
expect a 3dB increase in sound pressure
level by harnessing the boundary effect.
Proximity – Place the subwoofer as close
as possible to the primary listening posi-
tion. Sound dissipates indoors at approxi-
mately 4dB to 6dB for each time you dou-
ble the distance from the subwoofer to the
listener. Therefore you can expect a 4dB to
6dB increase in output every time you
halve the distance from the subwoofer to
the listener.
Improving the Stereo Image
Place the subwoofer(s) as close as possible
to the satellite speakers.
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