JBL P1500 User Manual
Page 4
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3. All joints should be glued and
screwed; do not use nails.
”Deck“ or ”Zip“ screws are rec-
ommended since they have
coarse threads for better grip
and don‘t require pre-drilling
holes. Once the box has been test-
ed, it should be sealed with caulk
around all interior joints.
4. Apply a 1" thick sheet of poly-
fill (available at fabric and craft
stores) to all inside walls except
the wall where the subwoofer is
mounted. If this is not done,
increase the recommended box
volume by 10 percent.
5. Use PVC or ABS pipe (card-
board tubing is acceptable if the
walls are over 1/16" thick). Keep
in mind the openings at either
end of the port must be at least
one port diameter away from any
obstructions inside or outside of
the box. Minimum recommended
port size is as follows:
8" Subwoofer – 2"
10" Subwoofer – 3"
12" Subwoofer – 3"
15" Subwoofer – 4"
Tools you will need:
• Straight-edge
• Saw (circular or table)
• Screwdriver (powered or
screwdriver bits in a variable-
speed drill are best)
• Sabre saw or keyhole saw
(to cut hole for woofer)
• Measuring tape
• Soldering iron and solder
• Wire cutters/strippers
• Utility knife (to cut carpet)
• Pencil
Materials:
• 3/4" or thicker MDF
• Caulk
• PVC or ABS pipe
• Deck screws
• Carpet
• Carpet Adhesive
(aerosol-type works well)
• Speaker wire (12 or 16 gauge
for woofers)
Take your time and mark the
wood carefully before making
any cuts. The old adage ”mea-
sure twice and cut once“ definitely
applies here. Use the straight-
edge to make sure your lines are
straight, and clamp it to the wood
to use it for guiding the saw if
you are using a circular saw.
This will get you the straightest
edges, the best fit and the best
sound.
overall cone excursion at the
expense of limited bandwidth.
1. Dimensions: Whenever possi-
ble, try not to make a box that
has dimensions that are equal to,
or multiples of, each other. For
example, a 10" x 10" x 20" box
would be susceptible to standing
waves that may cancel some fre-
quencies and add to cabinet reso-
nance. A better alternative would
be 18" x 11" x 10".
2. It is recommended that 3/4"
(19mm) MDF be used to build the
enclosure. Particle board is
acceptable, but it is more difficult
to work with. Enclosures for 12"
and larger subwoofers, or small
subwoofers, driven by high power
amplifiers should be constructed
out of 1" (25mm) material.