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ENCLOSURE VOLUME (CONT)
If we require a volume of 2.5cuft then we multiply this by 1728 2.5 x 1728= 4320 cubic inches.
We now take 2 known enclosure dimensions that we will use, e.g height and width and divide this figure
by them which will give us the depth, for example our height is 15”, our width is 20”.
So our depth is 14.4” for this enclosure.
Note
: this formula is for the INTERNAL dimensions, please add the thickness of the material used to
construct the enclosure to the formula to give you the outside dimensions.
So assuming we are using one inch material we need to add two thicknesses to each internal
dimension to allow for material top and bottom, so the external dimensions for this enclosure would be
17 x 22 x 16.4 inches.
The displacement of the woofer and the displacement of the port must also be added to the required
volume before you calculate the required sizes needed to build your enclosure.
Note
:
When using a port you must leave a gap at least equal to the shortest measurement of the port
between the rear of the enclosure and the port.
So for a 3” port there must be at least a 3” gap between the port and the rear of the enclosure.
Enclosure construction
Use at least 3/4 inch MDF (medium density fibreboard) or Birch ply to construct your enclosure
and at least 1 inch is recommended for the baffle. It is recommend that the panels are glued,
screwed and braced with sections of the same material you have used to build the enclosure
from. The BlackAir woofer is capable of producing internal pressures that can literally blow
apart badly made enclosures, so great care needs to be taken with the construction and
bracing of your enclosure. It is also worth sealing the joints with a silicone sealer once the glue
has dried to make a perfect airtight seal.
NOTE- Do not screw the Subwoofer into the enclosure within 24 hours of applying silicone
sealer to the joints.
The gases given off as the silicone cures can perish the surround of the Subwoofer causing a
non warranty failure.
Enclosure Volume
To work out the volume required for your enclosure please refer to recommended enclosure
volumes specified for your Subwoofer. These are listed in cubic feet. To convert cubic feet to
litres multiply the cubic feet by 28.3. If you use this formula calculating your enclosure size will
be easy .1 cubic foot is expressed as 12” x 12” x 12” = 1728 cubic inches
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If we require a volume of 2.5cuft then we multiply this by 1728 2.5 x 1728= 4320 cubic inches.
We now take 2 known enclosure dimensions that we will use, e.g height and width and divide
this figure by them which will give us the depth, for example our height is 15”, our width is 20”.
So our depth is 14.4” for this enclosure.
Note : this formula is for the INTERNAL dimensions, please add the thickness of the material
used to construct the enclosure to the formula to give you the outside dimensions.
So assuming we are using 1 inch material we need to add 2 thicknesses to each internal
dimension to allow for material top and bottom, so the external dimensions for this enclosure
would be 17 x 22 x 16.4 inches.
The displacement of the woofer and the displacement of the port must also be added to the
required volume before you calculate the required sizes needed to build your enclosure.
NOTE- When using a port you must leave a gap at least equal to the shortest measurement of
the port between the rear of the enclosure and the port.
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