Focal K2 POWER Serie Manuel D'utilisation page 15

Building the enclosure
Recommendations
Building your chosen enclosure,
whether sealed or bass reflex,
shouldn't be regarded as a "complex
job". Important observations should
never be neglected, such as correct
volumes, thick enough board ma-
terial, with added bracing, correct
sealing especially for sealed enclo-
sures. See image attached for further
understanding (fig. P).
Inverse mounting of subwoofer
(beauty box application)
Because all K2 Power KX subwoofers
use such large impressive multi-ferrite
motor units, why hide them inside?
Why not build a "beauty box", invert
the subwoofer, and make a feature of
their specialist design.
When choosing inverted mounting the
phase must be inverted, so that the
polarity is observed.
More importantly, inverting
subwoofer has inherent advantages
for the general performance. Primarily
for sealed enclosures, the overall ex-
ternal dimensions can be significantly
reduced, due to the saving of wasted
volume displacement otherwise lost in
traditional subwoofer installations. For
example, up to 3 litres can be saved
due to the same displacement lost by
the array of multiferrites and large
front and back plate assemblies and
chassis. For the 46 KX 4, around 4
litres can be saved for it's bass reflex
enclosure.
Building an enclosure
K2 Power subwoofers are able of
reproducing very high sound pres-
sure levels. The construction should
always remain strong and rigid, to
eliminate any unwanted vibrations. A
good material such as MDF (Medium
Density Fibreboard) will effectively
ensure this is possible. Choosing the
correct thickness of MDF compared
to the surface area decided, is also
critical to ensure the enclosure does
not vibrate. For this reason the gene-
ral thickness recommended is 19mm
MDF. The volume of the enclosure
depends on the type of music your are
listening to (hi-fi, dynamic bass...) (fig.
L, M, N, O).
If you decide to build your enclosure,
pay attention to the following recom-
mendations:
• Ensure that there are no air leaks at
corners and fixings.
• We recommend the use of clamps
for perfect assembly of the panels.
The drying time of the glue must be
the respected.
• When using the 46 KX 4, we advise
the use of a profiled port so that air
noises are prevented.
• Add damping material (foam) inside
the enclosure (do not use fiberglass) to
cancel possible resonances.
If the sound is "closed-in" then remove
some at the damping material.
Conditions of guarantee
All Focal loudspeakers are covered
by guarantee drawn up by the official
Focal distributor in your country.
Your distributor can provide all
details concerning the conditions of
guarantee. Guarantee cover extends
at least to that granted by the legal
guarantee in force in the country
where the original purchase invoice
was issued.
15 English