Enclosure Construction Tips
The GTi Subwoofer will only sound as good as the enclosure it is mounted in. Build an enclo- sure that meets the guidelines listed below and you will get the high performance bass you sought when you stepped up to GTi.
1.Box Dimensions - Try to choose subwoofer enclo- sure dimensions (height, width and depth) which are not equal or multiples of each other. This will mini- mize standing waves and resonance in the cabinet. Example: Ideal - 26"h x 17"w x 10"d; Not ideal: 30"h x 15"w x 9"d (30 is a multiple of 15).
2.Enclosure Material and Thickness - Use MDF or particleboard at least 3/4" (19mm) thick. With high powered amplifiers or subwoofers of 12" diameter or larger, use 1" (25mm) thick MDF or particleboard.
3. Joint Construction - All joints should |
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| CIRCLE DIAMETER | VENT (h x w) | ||||
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| 3.14 sq. in. | = | 2" | = | 1.75" x 1.75" | ||||
be glued and screwed (no nails). The |
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cabinet should be airtight and must |
| 7.07 sq. in. | = | 3" | = | 2" x 3.50" | |||
include adequate bracing to minimize |
| 12.57 sq. in. | = | 4" | = | 2" x 6.25" | |||
resonance. |
| 19.63 sq. in. | = | 5" | = | 3" x 6.50" | |||
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4. Fiberglass Application - Apply a 1" |
| 28.27 sq. in. | = | 6" | = | 3" x 9.50" | |||
blanket of fiberglass or polyester to |
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interior walls (except the baffle board) |
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of all vented enclosures. For sealed |
| Points on Power Handling | |||||||
enclosures (no ports) fill the entire volume with | |||||||||
fiberglass or polyester | The power handling of any subwoofer is | ||||||||
If you do not wish to use damping material then | related both to its ability to dissipate heat and to | ||||||||
make the box size 10% larger than recommended | the maximum cone excursion limits. | ||||||||
by the graphs. |
| • Too much electrical power can cause the wire in | |||||||
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5. Ports - Construct port tubes from PVC pipe or | the voice coil to overheat and burn out. | ||||||||
cardboard tubing with a wall thickness of at least | • Too much cone motion can cause the cone to | ||||||||
1/16". The end of the port tube must be kept one | |||||||||
mechanically limit and damage the subwoofer. | |||||||||
port diameter away from either the inside of the | |||||||||
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box or any surfaces in the car. |
| • Depending on the subwoofer model, the GTi motor | |||||||
If a port tube is not available, you may also |
| structure can easily handle an amplifier rated to | |||||||
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construct a square/rectangular vent. Changing
deliver from 300 – 600 watts of continuous power. This is an electrical rating dependent upon an enclo-
H
the shape of the vent will not effect the length as
sure design which keeps the woofer cone from
long as the surface area of the opening stays the
same. We’ve supplied a chart that lists some
reaching its mechanical limits when the amplifier delivers high power. Properly designed Vented and
W
D
standard dimensions for square/rectangular vents.
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