APPLICATIONS
The weather resistant drivers are
excellent choices for a wide range
of sound reinforcement, high level
playback, subwoofer, and monitor ap-
plications.
The 1508 HE BWX WR driver is
best used as the bottom end of a full
range enclosure. It has very high ef-
ficiency for superior output in the mid-
bass and mid-range.
The 1208 SPS BWX WR works
well in sealed or vented enclosure
designs, and its smooth, extended
frequency response makes it an ex-
cellent mid-range performer.
Because the 1208 SPS BWX WR low
frequency output is limited, it should
be used along with a subwoofer
when response below 60 Hz is need-
ed. The best application for the 1208
SPS BWX WR is in compact enclo-
sures and very high quality mid-bass/
mid-range reproduction at high sound
pressure levels.
The 15” drivers can work with cross-
over points as high as 2.0 kHz but
work best below 1.5 kHz. The 12” driv-
ers are usable to 3.5 kHz but perform
best below 2.5 kHz.
ENCLOSURES
To assist with the growing interest
in home built enclosure designs,
Peavey provides complete param-
eter data on these drivers, as well as
several recommended enclosures
for each model. This information and
much more can be found at www.
peavey.com.
The strength of the completed enclo-
sure has a great effect on the bass
performance of the finished system.
Box panels that aren’t stiff enough
will vibrate, canceling bass produced
by the woofer and creating unde-
sired sounds of their own. If your box
vibrates or you don’t think the box
panels are stiff enough, add more
bracing.
Vents used in the examples require
standard Schedule 40 PVC pipe for
vent construction. The pipe should
be dadoed tightly into the back of the
baffle and glued firmly in place with
high quality epoxy or high strength,
industrial grade hot glue. Rough up
the outside of the pipe to improve the
glue bond.
Be sure to account for the displace-
ment of the vent, bracing, horn (if
used) and woofer in your enclosure
before building it or it will be smaller
than its intended volume. This can
reduce bass output and mis-tune the
enclosure.
Line the inside of the enclosure with
polyester fiber batting such as quilt
stuffing. The batting material should
conform to California bedding fire
codes. Attach the batting with spray
adhesive or staples and keep materi-
al away from the end of the vent tube
where it can be pulled in by air flow.
Handles, protective corners, cabinet
covering, grille materials and cross-
overs are available through Peavey
Accessories.
When building a bandpass enclo-
sure, design a panel or door to be
removable for access to the woofer.
Use foam weather-strips to seal the
panel along with enough screws and
bracing to prevent leaks and buzzes.
Fill the sealed volume loosely with
polyester fiber, but leave the vented
volume empty. Place the magnet of
the woofer in the vented side for im-
proved cooling.
Peavey does not supply hardware
required for the manufacturing of fly
-
ing systems, and recommends that
builders should not suspend or fly
any enclosure not certified for such
applications.
These instructions are a general
guideline for design. Proper construc-
tion techniques, good planning and
common sense will result in a reli-
able, high quality, high performance
system.
Peavey in no way accepts liability for
any damage, accidents or injury that
may result from construction or use
of enclosure using this information.
Due to Peavey’s continuing efforts
to improve its products, features and
specifications are subject to change
without notice.
PARAMETERS
Thiele-Small parameters for Black
Widow
®
weather resistant drivers
follow. This data is for use in design-
ing enclosures. Numerous software
packages are available that use this
data to simulate the response of the
driver and enclosure together for opti-
mum performance in any application.
PARAMETER DEFINITIONS
Znom:
The nominal impedance of the driver in
Ohms.
Revc:
DC resistance of the driver in ohms, also
known as Re.
Sd:
The functional radiating surface area of the
cone assembly in meters 2.
BL:
Efficiency of the voice coil and magnet
system in Tesla meters.
Fo:
Free air resonance. Also known as Fs.
Vas:
Volume of air having the same compliance
(springiness) as the driver’s suspension.
Cms:
Restorative force of the driver’s
suspension in micrometers/Newton.
Mms:
The total mass of the moving parts of the
loudspeaker, including the air load, in grams.
Qms:
Resonance characteristics of the
mechanical factors of the loudspeaker.
Qes:
Resonance characteristics of electrical
factors of the loudspeaker.
Qts:
Resonance characteristics of the electrical
and mechanical factors combined together.
Xmax
: Distance the cone can move in one
direction before the coil begins to leave the
magnetic gap.
Le:
Inductance of the voice coil in millihenries.
SPL:
Typical sound pressure level at 1 watt, 1
meter.
no:
Electrical to acoustical conversion efficiency
in percent.
Vd:
Air displacement of the driver from negative
Xmax to positive Xmax.
Pmax:
Maximum continuous program power in
watts.
Disp:
Volume displaced by the driver inside the
cabinet when mounted on its rear flange
Summary of Contents for 1808-8 SPS BWX WR
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