Making a DIY subwoofer requires a few key components, such as strong glue and sturdy enclosure material. A subwoofer produces a lot of stress and vibration across its supportive enclosure, allowing the sound waves to reverberate throughout the space and emanate outward for a bass impact. All gaps must therefore be filled or covered for the best bass sound.
The simplest DIY subwoofer is referred to as a sealed subwoofer. The sealed enclosure is literally a box with a circular opening large enough for the speaker's front cone to protrude outward. The bass sound waves bounce within the sealed area for a steady, pulsing beat.
Sealed enclosures should be constructed from fiberboard. Using a powered screwdriver, multiple screws should be placed to secure all four sides, as well as the top and bottom, of the enclosure. In addition, generous amounts of carpenter's glue should also be applied, along with the tightened screws, to create an air tight internal space.
The front speaker mounting surface should be a double layer of fiberboard. This will give the DIY subwoofer a more stable position within the enclosure, as well as preventing unwanted vibrations that reduce the impact of the bass sound. Again, the craftsman needs to use liberal amounts of carpenter's glue to ensure a tight fit between fiberboard layers.
Bracing the DIY subwoofer with strong lumber pieces is another best practice for successful enclosure construction. A craftsman can glue 2 inch (5 cm) long wood pieces to each internal joint to counteract the constant sound wave stress. Adding even more wood strips to the internal enclosure walls will only help to strengthen the box construction.
A DIY subwoofer that is not designed to be perfectly square in shape, such as a rectangle, should have overlapping construction. In other words, the longer or larger sides need to slightly overlap the shorter or smaller sides. This design strategy creates even more support than if the pieces were attached end to end.
After the glue has dried, the enclosure joints should be filled and covered again with caulk. The glue may have produced gaps or cracks during the drying period. As any gaps within the enclosure will be detrimental to the overall bass sound quality, adding caulk will ensure that any gaps are filled completely.
Fiberboard is not an aesthetically pleasing surface once the DIY subwoofer project is complete. Customizing the enclosure's exterior can be accomplished by covering it with a number of materials, from carpet to vinyl. Some craftsmen enjoy painting the exterior, choosing complementary colors or even adding unique designs.