Tilted Forum Project Discussion Community - View Single Post - How to Build a custom fiberglass subwoofer enclosure.

krwlz · 09-27-2004, 05:47 PM

Well, we decided to build a custom enclosure for my car, after we did my friends.

SO I figured I would illustrate how we did it, as well as another method.

First thing, we used a piece of 12" sonotube cut at an angle and plugged in the bottom using some MDF to form the sealed part of the enclosure at the volume we wanted it. We added an MDF ring at the top to mount the subwoofer to.

I then mounted each tube to a piece of ply wood as the base. From there I used a combonation of carboard, duct tape, and spandex to form all of the curves I desired, then coated the whole thing with a coat of fiberglass resin, to give it a little stiffness, as you can see in these images.

Construction 1

Contruction 2

Contruction 3

At this point I had actually laid the first coat of glass, but you get the idea. I didn't take pictures through the entire process, but you get the idea from what I have here.

After this, is the painstaking process of adding at least 4 more layers of fiberglass, more in high stress areas. Much sanding goes on between layers, and actually laying the glass can be difficult, and take a bit of skill, as bubbles under the glass are your enemy. The cloth I used was actually scraps from my fathers boat building supplies, he purchased from System Three Epoxies. The resin (and cloth) can both be found also at Home Depot, and similar stores.

After the glass was sifficiently thick, we used bondo to finish everything out nice and smooth, and wrapped it in speakerbox cloth I purchased from www.crutchfield.com using 3M spray adhesive.

Finished Enclosure

Finished Enclosure

At this point, another route that can be taken is to have the box painted. We also considered laying one layer of glass on top of the bondo, then adding several coats of resin with pigment added to it.

I built a new wood floor into my trunk that the enclosure actually sits in. I also hinged it so that I can still access my spare tire and tools, albeit from the back.

Ultimatly, the amp(s) for the subs are going to go on the trunk lid roof (fiberglass mount built of course). With an amp sitting at an angle in front of the enclosure for the components I would like to add to my trunk. The amp will be housed in a metal frame, that hinges forward, to allow the enclosure to swing up and forward when I need the frame.

This is the method I used, and I believe we have found a better method to provide a mold to lay glass on, which is two part foam. Once hardened, it can be shaped reletivly easily to whatever shape is needed, provided a nice solid backing to lay the glass on. While we have yet to try this, my friend has some glass work to do on his car, and we are going to use this method. I will let you all know how it turns out.

09-27-2004, 05:47 PM	#1 (permalink)
krwlz Fledgling Dead Head Location: Clarkson U.	How to Build a custom fiberglass subwoofer enclosure. Well, we decided to build a custom enclosure for my car, after we did my friends. SO I figured I would illustrate how we did it, as well as another method. First thing, we used a piece of 12" sonotube cut at an angle and plugged in the bottom using some MDF to form the sealed part of the enclosure at the volume we wanted it. We added an MDF ring at the top to mount the subwoofer to. I then mounted each tube to a piece of ply wood as the base. From there I used a combonation of carboard, duct tape, and spandex to form all of the curves I desired, then coated the whole thing with a coat of fiberglass resin, to give it a little stiffness, as you can see in these images. Construction 1 Contruction 2 Contruction 3 At this point I had actually laid the first coat of glass, but you get the idea. I didn't take pictures through the entire process, but you get the idea from what I have here. After this, is the painstaking process of adding at least 4 more layers of fiberglass, more in high stress areas. Much sanding goes on between layers, and actually laying the glass can be difficult, and take a bit of skill, as bubbles under the glass are your enemy. The cloth I used was actually scraps from my fathers boat building supplies, he purchased from System Three Epoxies. The resin (and cloth) can both be found also at Home Depot, and similar stores. After the glass was sifficiently thick, we used bondo to finish everything out nice and smooth, and wrapped it in speakerbox cloth I purchased from www.crutchfield.com using 3M spray adhesive. Finished Enclosure Finished Enclosure At this point, another route that can be taken is to have the box painted. We also considered laying one layer of glass on top of the bondo, then adding several coats of resin with pigment added to it. I built a new wood floor into my trunk that the enclosure actually sits in. I also hinged it so that I can still access my spare tire and tools, albeit from the back. Ultimatly, the amp(s) for the subs are going to go on the trunk lid roof (fiberglass mount built of course). With an amp sitting at an angle in front of the enclosure for the components I would like to add to my trunk. The amp will be housed in a metal frame, that hinges forward, to allow the enclosure to swing up and forward when I need the frame. This is the method I used, and I believe we have found a better method to provide a mold to lay glass on, which is two part foam. Once hardened, it can be shaped reletivly easily to whatever shape is needed, provided a nice solid backing to lay the glass on. While we have yet to try this, my friend has some glass work to do on his car, and we are going to use this method. I will let you all know how it turns out. Last edited by krwlz; 09-27-2004 at 06:36 PM..