Custom Sub Enclosure Design - rough step by step - JCA Build

[crawjp]

Hey guys the following is a quick step by step (with images) of my VP's custom 12" sub enclosure design/build.

I use my boot everyday so it was important that I utilised all free/corner space possible without compromising the subs requirments.

Sub: Rockford Fosgate p3 12" dual 4ohm coils - 500w RMS @2ohm
***requires 40-50L internal airspace - with 4x9" port***



Initially I made several cardboard cutouts of the flat edges of the enclosure (bottom and 2 sides) this was a simple gauge of how much MDF to buy. (not much)

You then cut and shape these pieces out of 16mm MDF, glued and screwed them all together and planed angles into some of the edges to make them fit into each other flush. This gave the basic baseplate to work with. The square cutout of the back corner is to allow for the brake light housing. You'll also notice a semi-circle cut out next to the port to allow room for the towball struts in the boot.



You then cut out a ring roughly 14 inches to house the woofer. Brace it in a way that it sits up stable enough to fibreglass over (ie with wooden struts). mine is angled as such to prevent the boot hinge from closing on it (2" clearance to allow for woofer displacement during use).



Hard to see but this is how it fits in thus far.



You then cover the entire surface with old material (ie T-shirt) and staple it down TIGHT! dont worry about creases or folds - they can be pinned later.

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Trim excess and draw a mark to show where in thering you dont need to fibreglass.



Pin the folds.



You are now ready to coat! Coat it in fibreglass resin, let dry, then fibre glass the whole surface and let dry, 1 layer should do as we are also bogging the hell out of it! But 2 layers is better. If you have never used carbog before - work quicky in small amounts, it dries very fast. You will need a straight edge for your final layers, this process should take ages for begginers so dont rush.

Once this is complete you'll have to sand down all the bumps smooth, fill all the new indents you have found. Once finally dry coat in PVA or any glue really and stick down some cushioning foam on the surface, only has to be 5mm or so thick just to give that nice pillowing effect.
Also seal all edges from the inside with an industrial wood glue or sh!tloads of PVA.



Time to upholster! This one is a Blue Suede material but you can use anything, staple gun required here.



Cut excess and staple inside the ring and port hole.



Srew in your sub and your pretty much done ( i have falied to mention the + & - terminals I hide on the back and also insulating the inner surfaces with an acoustic treatment you can buy from craft stores/car audio joints etc.



Final product! - they go really hard guys, I am running my current sub through a 500w RMS amp and its very loud, very puchny but still giving a great tone, and its quite heavy so it doesnt move around at all.



Goal acheived boot space taken up - minimal



Cheers guys - Enjoy & tell your mates.

[crawjp]

I also use the same approach for my Speaker mounts:

6x9's on custom shelf:

[bezz]

Looks good mate. Shame the box is a little to big to fit snuggly in the corner, looks a bit strange sticking out past the boot opening like that. Its built to spec though for the sub which is good to see. Dunno about the suede tho lol, each to their own I guess.

Overall though mate good job on the install. It looks like you put in a lot of time and effort! I took the lazy way out and just bought a pre fabricated corner fibreglass enclosure. This one is sealed though and has a volume closer to 30L, much more ideal for my sub.

By the way don't know how well the admins here take to advertising your website so best be careful with that.

[daron]

looks good are you serious if someone put them in my rear shelf i would bash them

no offense thats a lot of work gone to waste
better luck next time

[bezz]

looks good are you serious if someone put them in my rear shelf i would bash them

no offense thats a lot of work gone to waste
better luck next time

lol i was more talking about the design of the sub box... less said about the 6x9 boxes the better...

[holdenboy]

Good work on the sub enclosure.....with a little more refinement it'll look sweet as. It also gives others an idea of how to build custom fibreglassed pods for front speakers etc. Not mentioning 6x9s at all bezz.......

[| evaN |]

Nice guide mate. Been meaning to try fibreglass for a while but im too lazy lol.
One question though, whats the best way to measure the volume?

[holdenboy]

For regular shapes there is a few programs available online that will calculate the box volume if you input dimensions.

For irregular shapes (like the one in here), a good way to measure it is by using packets of those little white balls you get to refill bean bags etc. They come in packs that are measured in litres. Just fill the enclosure up and you should be able to work out how many "litres" of balls you used.
Either that method or good ol' water....but MDF dosent like water

[crawjp]

For regular shapes there is a few programs available online that will calculate the box volume if you input dimensions.

For irregular shapes (like the one in here), a good way to measure it is by using packets of those little white balls you get to refill bean bags etc. They come in packs that are measured in litres. Just fill the enclosure up and you should be able to work out how many "litres" of balls you used.
Either that method or good ol' water....but MDF dosent like water

Yeah stick with the bean bag balls idea, you can pick them up from department stores, Kmart etc.

cheers holdenboy.

[bezz]

just got my enclosure.. fits perfectly in the boot with no overhang and looks almost factory. I reckon you'd be onto a winner mate if you model them closer to this:

[crawjp]

just got my enclosure.. fits perfectly in the boot with no overhang and looks almost factory. I reckon you'd be onto a winner mate if you model them closer to this:

Thanks Bezz, yeh ive seen these around but they have a very small internal volume (< 1cu. ft.) which isnt ideal for the sub I am running, also they come made with only 2 max layers of fibreglass, very bendy and reduce the subs performance, id reccomend patching a few more layers on the inside for added strength, they do loook sexy though, very snug fit.

thumbs up!

[holdenboy]

How good does that sub look though....*drools......mmmm SQ goodness*
lol.

[bezz]

How good does that sub look though....*drools......mmmm SQ goodness*
lol.

lol cheers man.. its killing me i havent even been able to hear it in action yet! This weekend itll happen finally!

[vedanny]

hi can any one help me im looking for a sub for my ve one that molded in to the boot they make them for a vt to vx thank