Subwoofer truck enclosures are offered in a variety of shapes and construction designs based on the vehicle's available space. Most subwoofer truck enclosures are made of fiberboard, rather than fiberglass, so the speaker assembly can fit under a seat or pressed against the cab's back wall. The limited truck space usually restricts the construction design to a sealed or ported box.
The subwoofer speaker itself provides the low frequency bass found in many music genres, from rap to heavy metal. Enclosures must hold the speaker in place while enhancing the sound as it exits the combined speaker and box. Passenger car trunks are usually the best area to store a large subwoofer enclosure; however, pickup truck owners would often like the same bass enhancement. As a result, many enclosure manufacturers cater to truck owners and operators specifically to create conforming boxes for the small cab space.
Basic fiberboard boxes, with openings for the speaker, are common subwoofer truck enclosures that fit directly under the driver's or passenger's seat. The speaker faces toward the seat's underside so that the bass sound vibrations emanate directly up to the listeners. Consumers must measure the space available under the seat before purchasing a speaker and enclosure combination; larger subwoofer speakers will not fit under a typical truck seat.
Some manufacturers are designing custom subwoofer truck enclosures to fit popular truck models. A consumer could purchase a tall and narrow enclosure designed for his or her cab's back wall space. This design places the speaker and enclosure combination flush against the wall for both extended and regular cabs. Typically, the speakers are positioned at the top of the enclosure for closer proximity to the listener's ears.
Limited space dictates the internal design of subwoofer truck enclosures. Sealed enclosures only have one opening for the speaker; the box is effectively sealed at all connection points to retain the reverberations while in use. Under seat and wall enclosure types can both have this design. It is the simplest box construction, and generally an affordable option.
For those who would like a more powerful bass output, on the other hand, ported subwoofer enclosures are the better option. Ported boxes have an opening for the speaker, but also retain an internal tube to funnel the bass sound outward from the speaker's rear to the enclosure's outside. Due to space constraints, under seat enclosures are not able to have a ported design; however, wall enclosures can easily incorporate this feature to produce powerful bass sounds.