2010 Custom JL Audio installation (fiberglass molded box / with amp rack)

#1
This thread is not meant to be a detailed "how-to." It is meant to be for informational purposes, and as the first link in my buildup thread for my corolla. I will give some details along the way, but as I was not intending to create a writeup, I skipped a few steps here and there between photos.

I used to be a professional installer, but I quit to work an IT job and save the energy for my own personal projects. Comments, questions and criticism are welcome. I know that some of us don't care for stereo systems anymore, but I will always have a love for music and good sound quality. Thus, rather than a trunk full of speakers, amps, fiberglass and wood, I intend to have a fully functional trunk with a cleaner, less in your face audio system.

I also no longer have a shop with a nice routing table, and endless supplies. Everything here is done by hand. I used a jigsaw for the baffle holes and a palm sander for the surface. Nothing crazy.

Here is where I started:

This video shows a quick look inside the trunk of the 2010 Corolla. I decided that the pocket in the right hand side is a great fit, and perfect amount of airspace for this sub.

Another peak at that pocket. We will removing that little plastic compartment on the floor and using the line from the carpet to make the shape of the box that will replace it. This way our factory trunk mat can stay, and fit properly.



Then I pulled out the liner from the truck to wrap with tape. This is a 3m masking tape. I prefer the 3m because it is thick, and doesn't leave any residue from the adhesive behind.




A good covering of turtle wax over the tape so that the fiberglass resin doesnt soak through, and doesn't adhere to the tape. This allows the box to pop right back out of the liner when its formed.



Next I created a mockup of placement of parts in the trunk. I used this mockup to create an outline of the edge of the box with a pen. If a good solid line is created, then it will easily show through many layers of fiberglass and allow an easy trim of the finished box.






Here is a raw mold of the first layer. At this time, the molded section can be removed from the trunk panel.



Now it is time to test fit everything in place. Test fit, test fit, test fit. You can never test fit anything too much. In this scenario, our trunk lid bracket closes really close to where the face of the box is going to be. So I test fit a lot of times throughout.

 
#2
The baffle (aka the side of the box the speaker mounts to) is created separately. I set the mounting point inward at the bottom to create a slight angle difference between the plane of the subwoofer and the face of the box. I did this by setting two screws at about an inch an a hlaf of height and then one at the top at about 2 inches of height and flipped it over. After glassing everything together, you end up with a nice mounting ring for the subwoofer to mount to. (i missed a few pics here)



The molded box gets wrapped with plastic wrap to give a false face so that I can set the baffle ring in place to be molded to the rest of the box. I have two 4x6 pieces of glass mat that I glassed and left to dry. After drying, all the plastic wrap can be removed and the rest of the baffle can be created.



A little tip here... Spray adhesive is your best friend when doing areas like this. I used it all around the box, placed all my matting in place, and then let it sit. After a few minutes I glassed it just enough to get it wet. Also, I am using the thinner, grid woven matting for this part as it doesn't require as much resin to soak through to create a sturdy layer. I light coat of resin over this type of matting will do. I switched back to the kitty hair style matting after the first layer of the baffle was complete.



Try to prevent sagging as much as possible, to avoid robbing airspace, and prevent the need for lots of body filler. Little sags can be easily filled in with bondo.



Once you have enough layers, a quick sand of the surface and a nice layer of body filler to smooth it out.



And another test fit. This is probably my 5th time shoving it in the trunk.



Here I added another .5" ring to the surface to allow more definition to the face. I also bullnosed (beveled, chamfered, etc) the inside of the ring to allow the carpet to wrap into it nicely.



A quick layer of bond around the ring to smooth it into place. And another quick sanding. (not pictured)



Here is the last step before you wrap the box. This is half bondo / half fiberglass resin. I mix the bond and the fiberglass resin completely without hardener. Then I add the fiberglass hardener and mix it, and lastly the bondo activator. In this order, you will have the most working time.

After its all mixed up and ready to go, pout it into the box and turn the box in all directions to give the inside a good coating of the mixture. This makes it "pretty" and nice and solid and stiff. It is not required but I won't go without it.

 
#3
Finally, we get to wrap the box. I started with the baffle ring, and worked out. But before I set all the carpet in place, I set the face of the ring, and pressed the speaker into place to stretch the carpet into the inner part of the ring. Once my speaker was in place, I finished pressing the rest of the carpet into place.



And a nicely finished box in the trunk. Out of the way. And if I wanted to, I could build a grille cloth insert to cover up the speaker.



I will be building the amp rack this weekend so stay tuned for more.
 
#5
Bro,,that is absolutely amazing,,finally someone who really takes pride in their work..awesome. ..im in Riverside Ca..u ever want to make so extra $,,not by making me one just hands on ..anyhow amazing
 
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