Fiberglass subwoofer enclosures present some real advantages for a custom car audio setup. First, they can be shaped to fit a specific vehicle or space within a vehicle, taking advantage of space that couldn't be used with a normal rectangular subwoofer enclosure. Second, if properly executed, they can present a real custom look that will make your car audio system truly "one of a kind."
Instructions
1. Determine the size of enclosure you'll need. Subwoofers are usually designed to operate in a specific volume of air. Put them in too small or too large an enclosure, and they won't perform well. Using the specifications given by the manufacturer, determine what the volume of your subwoofer enclosure should be.
2. Design your enclosure to match the sub's specs and your needs. Make preliminary measurements of where you'd like to place the subwoofer and match it against your sub's volume specs. You may find that you'll have to make adjustments in your original ideas. Sketch out possible designs and determine how well they'll work in your car. Remember, the volume of the enclosure is key to good performance.
3. Build a form to lay your fiberglass on. You can build the form by shaping foam, or by building a form out of wire and then layering upon that. Remember that you'll need an opening for both the subwoofer and the wiring terminals, and it's better to build these into the enclosure, rather than have to cut the enclosure later. Use a putty knife or spatula to smooth the fiberglass mixture as you go along. After mixing your fiberglass mixture, put down your first layer upon the form. Once the first layer is complete and dry, add another layer, checking for smoothness and a clean line as you go.
4. When you've completed laying the fiberglass on the form, smooth it with a heavy file or cheese grater so that it matches the shape you're looking for. Using progressively finer grades of sandpaper, smooth the fiberglass until the finish is smooth and consistent. Paint the enclosure the desired color and then add a layer of polyurethane gloss so that the box sports a sheen.
5. In the openings you've left in the enclosure, mount the speaker wire terminals, and attach internal wiring. Connect this wiring to the subwoofer and then mount the subwoofer. Test the subwoofer for operation. Now mount the enclosure in your car -- use brackets to hold the enclosure securely in place.
