My First DIY Fiberglass Sub Box

[TTownEP]

Well, I've been working on this off-and-on for about 2 months now. I'm not quite done yet, but I feel like I'm at a point where I can show the progress.

So first the backstory. Someone at work had 2 of these JL 12W1v2 subs for sale for a good price. They were in great shape, barely used. I had been wanting to get rid of the little 10" I had that was mounted in a small wedge box. It didn't sound that bad, but I didn't like the box taking up my trunk space. I always carry stuff back there, and it was just getting on my nerves. I guess I didn't strictly have to buy a new sub to make a new box, but it certainly made me more motivated so that the money I spent on the 12"s didn't go to waste.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/6664cac5.jpg

So my first step was to mock up what I wanted with a bit of cardboard. It didn't turn out like the mock-up in the end, but it got me thinking about ideas. I was going to try to build it out of all MDF, and make it fit into the side cavity back there. After a couple hours of mocking and testing, I soon decided there was no way my carpentry skills could make a box to fit those curves. So I then decided to try my hand at fiberglass. My only experience with it was working with the UA Formula SAE team, building a seat. Which they already had a mold for. All I did was lay it flat in the mold and hand it off to the upholstery dude for finishing.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/cfb51974.jpg

I probably should have read up on some instructions first, but I ended up just diving right in. I went and got some 'glass, resin, sponge brushes, and aluminum foil.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/6995df63.jpg

After I got all my foil in there, I just started laying the fg in, and sticking it up everywhere. If you've never used it before, it kinda works like paper-mache. In hindsight, I probably should have used some sort of mold release so that I didn't have to pick all that foil out of the back when I pulled it out, but oh well. I ended up spray painting over the first layer with black so you can't see it from the outside.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/0c4d2a30.jpg

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/30f6bda5.jpg

Once it got dried out, I just pulled the whole thing out.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/30bbe7a8.jpg

Now there are some missing pictures here, but basically next I just filled in the gaps and finished out the basic shape. Then I laid it out on my piece of MDF and traced the shape for the front piece. After cutting this out, I laid the glass out around the edges to secure the front and back pieces. I did this over several days, making sure all the holes were filled, and that I had a good seal around all the edges. Then I went back and laid another layer on the back to strengthen it up.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/71bb1df9.jpg

Then I went about cutting the speaker, terminal, and courtesy light holes. Oh, I wanted to keep my trunk light, so I made a hole for the original light to snap in there. I don't have it wired yet, that's one of the details I have to finish out here in the next few days.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/b99fbef3.jpg

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/9b49eb81.jpg

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/bab9e441.jpg

The carpet job I did here kinda sucks. I used 3M spray glue to hold it down, which I've used on several simpler, square boxes. This curvy thing was a bit of a challenge, and I really have no clue what I'm doing here, haha. I still have another equal-sized piece of carpet, so I'll have to take another whack at it. Also, I will probably paint that plastic terminal piece so it doesn't stand out so much.

The light hole is still under that carpet, I haven't cut a hole for it yet, so it's not really sealed yet. But anyway, I'll update when I actually finish it.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/7ec48e97.jpg

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/42f5747a.jpg

Any opinions?

[oldschoolimport]

damn dude, that turned out pretty good. and it doesn't kill your trunk space. I like it...

[johnkimble]

looks pretty good. i like the idea of keepin the light... wouldn't have been the way i would have done it but that doesn't make it bad!

keep up the good work, looks great for your first attempt for sure.

[trippy]

good shit homie

[introvert]

Nice work! Been wanting to buy a box like that

[TTownEP]

Nice work! Been wanting to buy a box like that

Since I had the extra sub, my plan was to build 2 of these boxes, but after all that work, I dunno, haha. I was thinking about maybe using this one to make a mold. I have been wanting to try out vacuum forming. Perhaps if I were to build a vacuum table, I could make a few plastic molds to fit that space for people on here to use for boxes.

[Chad]

Good job... seal the shit out of that light once it's int here, it really does need a good seal to prolong the life of that sub.. it will also increase low end extension.

As for carpet, Parts Express sells un-backed carpet, I used it on mine and it's easy to work with... only issue is that if you use it on the floor like I did, it pills up easily.

[BaLisTek]

i dont think vac forming would be the optimal way at recreating this piece.

look at this vid.
http://www.youtube.com/watch?v=tXlHpLb-9RY

[Chad]

i dont think vac forming would be the optimal way at recreating this piece.

Look at this vid.
http://www.youtube.com/watch?v=txlhplb-9ry

that's totally kickass.

[BaLisTek]

yea it is, just a simple 2 part mold to help. I mean vac-forming would be quicker but I just dont think it would work. It would be more expensive up front. You would need roughly a 3'x3' vac forming table with a source of suction strong enough to pull. This is mildly inconvienent but could be built just using pegboard. 1 or 2 shop vacs could probably provide the amount of suction required.

The big problem that you would come into is designing the heating element. No oven is gonna be large enough to handle this size of sheeting. One would have to build their own heating unit. You would have to build one using HardieBacker cement board. And you can't just build a rectangular box . Regarding the physics of heat distribution and transfer, the edges need to bevel up at a 45 degree angle in order to properly heat the edges of the plastic. Thats just the enclosure, for the actual heating element, you would have to a lot of coil pegs and get the coiling and properly distribute them on the base with some thinking as to their layout. Sorry for the noob terms, I havent looked into this in bout a year. I remember it not being very cheap it all. The structure has to be tall enough also.. to allow for sag of the plastic . And finally, HardieBacker cement board does break over time with repeated use. I promise it would cost hundreds of dollars to set this up not even counting trial and error expenses. Then also, finding abs or polystyrene sheets thick enough to accommodate the housing. I know nothing about audio enclosures, but shouldnt the box have some thickness to it for sound quality?

Again, not trying to be pessimistic, just trying to give some info where I have some knowledge of the process.

I wish you were local tho, I love making molds.

[TTownEP]

No no, thanks for the heads up man. I haven't done any research on this, I was just talking out my ass, haha.

That was a cool video. How do you get such a clean mold in the first place?
And apparently I should have used fiberglass mat, not cloth. That looked a hell of a lot easier.

[BaLisTek]

well luckily, surface condition isn't as critical if you plan on using carpet. I mean if you wanted, you could simply spread some rondo onto the back of you original and then sand it once it is cured. That would take away all the fiberglass cloth showing through on the backside. Once that is done, you have to create a parting line on your box so that you can make yourself a 2 part mold.

Here is a video kinda showing the process from start to end. its a two part so watch the 2nd afterwards. http://www.youtube.com/watch?v=gzng9HeGNPE

[Sucka]

damn! i want one now.

[TTownEP]

Wow, thanks for the links B. Awesome info.

[BaLisTek]

no prob.. i have a soft spot for making things

[BeaterEP]

no prob.. i have a soft spot for making things

Yeah? :mbiggrin: Ya wanna make me a matched set of FG boxes, like the OP's, but for 10s? It was my birfday Friday, call it a belated gift! :mangel:

Seriously though, nice work OP! I've been thinking about something like this myself, same deal with some well-priced speakers that I don't want to go to waste, but without gobbling up all the hatch space. Keep us updated on your work! :thumbu:

[TTownEP]

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/d4f20060.jpg

It sounds so much better since I got it sealed up good. Now I just have to chase a few rattles in my passenger door, and figure out a way to keep it from falling over. Now that it's been in there for a few weeks, the carpet has compressed and it wants to fall over.

[TTownEP]

I also watched a lot more YouTube videos from that guy on fiberglassing that Balistek posted. There was definitely some good tips and tricks in there for next time.

Also, the other matching speaker to this one is for sale over in the classifieds.

JL Audio 12W1v2 - 4 ohm (http://www.ephatch.com/forum/showthread.php?55816-FS-12-quot-JL-Audio-Sub)

[johnkimble]

i wonder if you can get some nice strong velcro and secure it that way? you know the really wide kind that comes in a roll?

[TTownEP]

i wonder if you can get some nice strong velcro and secure it that way? you know the really wide kind that comes in a roll?

I actually thought about that. Right now, I'm just taking right turns very carefully, haha.

[james04si]

I know you are not going to like hearing this but the only proper way to hold it down is with a bolt through the bottom of the hatch. Thats how I did mine and its not going anywhere. Anything less than bolting/screwing it down is a gamble. Plus it makes it that much more difficult to be stolen.

[TTownEP]

If I did that, I'd have to put more sealant and one HELL of a fender washer in there to keep the fiberglass from breaking out. My other plan was to put some kind of little lip at the top just to keep it from tipping. And as for theft, I really am not that concerned, since you can't see it with the parcel shelf in there. I actually had someone "break in" one time when I forgot to lock the doors. All he took was my iPod nano. Left my amp and sub untouched. I don't think he even opened the hatch. He did release the handbrake though, and let my car roll out in the street. That was weird.

http://i22.photobucket.com/albums/b329/gryanholland/Civic%20Si/Speakerbox/062a53ac.jpg

[james04si]

Maybe I went overboard with the thickness of my fiberglass, But then again i did use MDF for the bottom.

http://albright.ws/Pictures/My%20Cars/Civic%20Instal/photos/DSC01673.JPG

http://albright.ws/Pictures/My%20Cars/Civic%20Instal/photos/DSC01711.JPG

[ttttrigg3r]

I love this box OP. Let me know if you want to make one to sell or want to sell the one here. Are you getting good clean sound?

[firmk20]

dude you should totally fab some more of those and sell them on here. I know that there are a lot of people who could use a box like that. Looks really good.

[krod]

Great looking box,came out very nice.

[BeaterEP]

ITT: we all try to get up on some dude's box. :biggrin1:

[civictype_r04]

Looks good dude!!!

[TTownEP]

dude you should totally fab some more of those and sell them on here. I know that there are a lot of people who could use a box like that. Looks really good.

What would someone be willing to pay for one of these?
I could make a few (and an improved one for myself) if someone made it worth the time. I would definitely beef it up a little bit, and make it much cleaner looking.

[TTownEP]

Are you getting good clean sound?

This one is really thin. I can hear the back moving if the seats are down. I got a couple of free bags of glass mat and some resin from my mom's house, I'm going to try to make a new one.

[ttttrigg3r]

So how much would you charge to make one of these? how about make me one for 60$!? I'll pay more if you can guarantee that it's solid and have a way to run the light there. =] Oh hey how did you cut that MDF board for the front? just hand held jigsaw? And how did you attach the mdf front to the glass back? is it just laying it down on top and putting glass and resin all over where they meet?

[james04si]

if your talking about my box for the front peice I cut the outside with a bandsaw. cut the inside with a jig saw and used a router bit to cut the opening for the speaker itself. I used dowel rods and fiberglass to hold it in place until I streched the front over it and glassed it in place permenatly. Also there is no way I personally would ever do this for $60. Ive got more than that just in the materials that went into it not to mention how much of my time it took to make it. Plus after that project I determined that I really hate fiberglass and wouldnt touch the stuff for anyone besides myself :)

[ttttrigg3r]

lol no wonder custom boxes are so expensive. one day i'll get so sick of my bigass box i'll attempt this.

[BeaterEP]

Yeah, only way to cut costs on something like this would be producing them in volume, I'm thinking. :mcry:

[james04si]

lol no wonder custom boxes are so expensive. one day i'll get so sick of my bigass box i'll attempt this.

Yeah thats what finally made me decide to downgrade to a single 12L7 in a sealed box from a single 15L7 in a ported box

http://albright.ws/Pictures/My%20Cars/04%20Civic%20Stereo%20Install%20Page/photos/Kicker%2015L7%20Ported%201.JPG

And before that I was running 2 15L7 in a sealed box

http://albright.ws/Pictures/My%20Cars/04%20Civic%20Stereo%20Install%20Page/photos/Kicker%2015L7%20Installed%202.JPG

[SIisaLowRydaEP3]

DAMN!!!! and i thought i had no space

[doubledouble]

Do want. Need bad.

[square_1]

It looks rad! I really like it. The only problem I see is the incorrect volume for the sub you are using. There is a lot of math involved in sub boxes to get the right sound without overtones and other crap like that. Most people might not care but you could make your sub sound really bad in that box.

Not hating on your idea, just something to think about if you think about making them for other people. :)

[TTownEP]

No, I wouldn't make mine for $60 either. It took awhile.

My ratio for space saving versus SQ was about 70/30. I don't want it really loud, and I'm not a huge audiophile. I do want A sub, but I carry stuff in the back ALL the time, so it's important that it take up as little room as possible. I really like Chad's box with the raised floor and the spare tire sub box, but it looked like a lot of work. I also wanted to keep the light, but if you look at it, the hatch area is not symmetrical. The driver's side shape would allow less volume for the sub, so it had to go on the passenger side.

[doubledouble]

No, I wouldn't make mine for $60 either. It took awhile.

My ratio for space saving versus SQ was about 70/30. I don't want it really loud, and I'm not a huge audiophile. I do want A sub, but I carry stuff in the back ALL the time, so it's important that it take up as little room as possible. I really like Chad's box with the raised floor and the spare tire sub box, but it looked like a lot of work. I also wanted to keep the light, but if you look at it, the hatch area is not symmetrical. The driver's side shape would allow less volume for the sub, so it had to go on the passenger side.


When are you going to start fabbing these for fellow members? ;)

[Chad]

ROFL... Overtones.