By creating a custom fiberglass subwoofer enclosure, one can make their subwoofers fit into the style and design of the entire car. Many enclosure designs, shapes, and sizes can be created; however, this guide will help anyone learn how to create a custom subwoofer enclosure. The knowledge gained from this guide can easily be applied to any specific project, in order to create a custom fiberglass subwoofer enclosure.
Tools Needed:
- 100-400 grit sandpaper
- Nail gun/nails and hammer
- Staple gun
- Paint brush
- Handsaw/jigsaw
Materials Needed:
- Cloth Fiberglass and Resin kit
- Plywood or another type of wood
- 1/2 inch dowels
- Car paint or carpeting
- Fiberglass auto body filler
Once you have gathered all the tools and materials, it’s time to start designing your custom subwoofer enclosure. Start by choosing the direction you want the subwoofers pointing, where you want them placed in your vehicle, and a general design. Then, create a rough sketch of your desired design. Now, it’s time to think about the mathematics and begin building.
Subwoofer Enclosure Design
Begin by measuring out all the base area of where you will place your subwoofers. Then, you must make sure you create a subwoofer enclosure big enough to house your subwoofers and produce quality sound. Each 12″ subwoofer generally needs around 3 cubic feet of space; while 8 and 10 inch subwoofers should have 2 cubic feet of space to produce the best sound.
In order to measure and design an enclosure with the proper cubic feet, take the base measurements that you just measured and divide it by the number of subwoofers you will be placing in the enclosure. Once you figure out how much space each subwoofer will have at the bast of the enclosure, take the length and width measurements and multiply them.
For example, someone may have a base with the dimensions three feet by two feet, which is six square feet. If they will be placing two 12″ subwoofers in the enclosure, the base for each subwoofer will be three square feet. So, they will need to make the subwoofer enclosure one foot high, in order to make three cubic feet of space for each subwoofer.
Building a Custom Fiberglass Subwoofer Enclosure
After you have figured out the dimensions and finalizing the design, it’s time to start building the base structure of the custom subwoofer enclosure. Begin by cutting the base of the subwoofer enclosure out of a sheet of plywood with your handsaw or jigsaw. Once you have cut the base out, place it off to the side and grab your 1/2 inch wooden dowels. Cut four wooden dowels for each subwoofer to the necessary height that your subwoofer enclosure needs to be, using your handsaw or jigsaw. Finally, cut perfect circles out of a sheet of plywood to fit under the rim of your subwoofer, so you have a solid wood base to place on-top of the wooden dowels, in order to support the subwoofer. Subwoofers usually come with a punch-out template to use in order to perfectly trace and cut the best circle to fit your subwoofer.
Now it’s time to put everything you cut together, beginning with nailing each circle rim to four of the wooden dowels, evenly separating them around the rim, which will distribute the weight of the subwoofer evenly. Finally, nail the other end of the of the dowels to the base board of the subwoofer enclosure in the spot you wish to place the subwoofer where you would like. You now have the base structure built for your subwoofer enclosure. Place this into the vehicle and get ready to fiberglass.
You now have to begin applying your fiberglass cloth, draping and stapling, or nailing, it from the wooden circle which will support your subwoofers to the edges of the base board, at the bottom of the structure. Make sure every spot is covered with a layer of cloth, then begin applying the fiberglass resin onto the cloth with your paint brush, spreading an even layer on the cloth. Repeat this, until you have several layers of cloth resin applied on the custom subwoofer enclosure, and let it dry. You now are done building the structure and you simply have to do the finishing details.
Carpet or Paint a Custom Subwoofer Enclosure?
One can either choose to carpet of paint a custom subwoofer enclosure. Carpeting can be much easier and cheaper, but it may not look the best and it may not even match anything else you’ve done to the vehicle. The alternative to carpeting is to sand and paint the enclosure. Sanding and painting does take much longer than carpeting, but it will definitely look much nicer and match your vehicles overall design, if done properly.
In order to paint a custom subwoofer enclosure, you have to begin by sanding the enclosure with 150 grit sandpaper, then eventually moving to 200, 250, 300, and even 400 grit sandpaper, in order to get the fiberglass resin smooth and to minimize imperfections in the exterior fiberglass structure of your custom subwoofer enclosure. Make sure you are wearing a mask, since the dust created from fiberglass is horrible for your lungs!
If you end up sanding and having holes or pores appear in the fiberglass, you should use fiberglass auto body filler to make the entire exterior of the structure as smooth as possible, as any imperfection will show up after you paint, so make sure you fill in every hole, low spot, and imperfection!
Once the exterior is smooth, sanded with 300-400 grit sandpaper, and ready for paint, mask off all the other areas of your vehicle, so you don’t get over-spray all over the vehicle. Make sure you are using a paint that is somewhat flexible and matches the exterior of your vehicle, so it can take the pressures created by the subwoofer and blend in perfectly with the overall design and color scheme of your vehicle.
Ending Steps
Once you’ve either carpeted or painted your subwoofer enclosure, it’s time to finally wire and mount your subwoofers into the box, and do any last minute detailing, including paint touch-ups, wet sanding, or cleaning.
You should now know the basic process to building a custom fiberglass subwoofer enclosure. Use this basic guide in and customize it to the process you must take to create your custom subwoofer enclosure, which sounds and looks perfect in your vehicle.