strongly discouraged, but if no
better material is available choose
grade BC or better and don’t use
wood with loose plies or voids.
Use quality wood glue and fit
joints tightly. Dado corner joints
are highly recommended. Wood
screws or a pneumatic nailer
should be used to assemble
the enclosure during gluing to
maximize joint strength.
The strength of the completed
enclosure has a great effect on
the bass performance of the
finished system. Internal bracing
will be required to improve the
structural stiffness of the cabinet
the Lo Max drivers will generate
enormous forces inside the
enclosure, and panels that aren’t
stiff enough will vibrate and cancel
bass output while producing
undesirable resonances.
Vents shown 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.
Radius the inside of the
vent ends to improve air flow and
reduce vent noise.
Lo Max drivers generate huge
amounts of heat at high power.
This heat is transferred to the air
in the enclosure as it is dissipated.
For long term (i.e., greater than
15 minutes) high power operation,
this heated air must escape and be
replaced by cooler air. Enclosure
vents should be placed at the top
and bottom vents. Enclosures
not designed in this way will be
thermally de-rated, and will not be
capable of sustained operation at
high power due to heat build- up.
Vents for these enclosures are
much longer than typical for a
sound reinforcement subwoofer.
This reflects the special
characteristics of the Lo Max’s
design that make it possible to
combine a large, high excursion
woofer with an unusually small
enclosure. For best performance,
the inside ends of the vents should
be a distance of at least one vent
diameter from any interior wall of
the enclosure. The vent should
be straight, without elbow fittings
or other methods to bend it for
greater length. Vent diameter
should not be decreased, as high
air velocity will result in noise and
reduced power handling.
Be sure to allow for the
displacement of the vent, bracing
and woofer in your enclosure
design before building it. Mistakes
in net volume will mistune the
enclosure and can drastically
reduce performance. This will
require considerable planning
before construction, but is well
worth the extra effort.
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
material 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 crossovers are available
through Peavey Accessories. Take
particular care when positioning
the handles, as subwoofers tend to
be large and heavy.
Do not use ¼” phone plugs or
jacks in the construction of your
enclosure. The power capacity
of Lo Max drivers is well above
safe limits for phone plugs
and jacks, and their use may
constitute a fire hazard. Neutrik
®
Speakon
®
connectors are highly
recommended, and internal
cabinet wiring should be at least
16-gauge stranded copper wire.
These instructions are a general
guideline for design. Proper
construction techniques, good
planning and common sense will
result in a reliable, high quality,
performance system.
Peavey in no way accepts liability
for any damage, accident or
injury that may result from design,
construction or operation of
enclosures using this information.
PARAMETERS
Thiele-Small parameters for Lo
Max subwoofers follow. This data
is for use in designing enclosures.
Numerous software packages
are available that use this data
to simulate the response of the
driver and enclosure together
for optimum performance in any
application.
