Want to make a Custom box, need help!

[thewifesyaris]

So I have had my rear seat removed from my car for over a year long now and have had a small bazooka tube in the rear. No with all of this extra room and summer around the corner I want to make a custom box for a 10" sub and tidy up the rear to make using that space a bit easier. So my plans are to place the sub and amp in the lower part of the cavity, where your feet would be, and raise that area up to the level of where the lower part of the seat would have been. In other words the trunk area will be level with where the seat would have been all the way to the front seats, with margin to allow the front seats to recline.

My question to those who have done similar boxs is what materials did you use to make the fiberglass box? I plan to use plywood for most of it, but I have only read up on a few here who have used fiberglass and resin to make a custom box. Any ideas of where to get something like that?

[yarrr]

I'll let one of the resident audio experts chime in, but I believe MDF is better than plywood for boxes. That's what I made mine out of. You can get fiberglass patch kits from auto zone that will be way more than enough fiberglass, but you'll probably want the foam too, and that doesn't come with the kits

[severous01]

no plywood. the chunks vibrate loose and weaken the panels. 3/4" mdf is prime.

[TinyGiant]

i will post my tutorial i did :) i have a custom built box in to the floor :)

[TinyGiant]

here it is!

http://www.yariscentral.com/index.php?topic=4.0

[talnlnky]

In order of cost, going from lowest to highest

1: 3/4" Particle Board
2: 3/4" MDF
3: Baltic Birch or a Marine Grade Plywood
4: 3/8" Fiberglass

In terms of which is best.... Particle board blows, it strips screw holes way too easy. MDF can also strip screw holes so I'd suggest using T-Nuts or Hurricane Nuts & machine screws with them. I (and many Home theater enthusiasts) personally believe the Birch & Fiberglass are the best, but they take a bit more skills, and are much more expensive to work with.

MDF is a very dense/heavy wood that is easily damaged when dropped or when exposed to water, BB is about half the weight, and a bit stronger/more rigid, and is relatively resistant to water. NEVER use the normal cheap plywood, it's a completely different story than Baltic Birch. Fiberglass is great for curved surfaces, but you never want to use it for flat surfaces/sides as it is really weak if it is not curved.

When people make fiberglass sub boxes, they still use a decent amount of wood.
For what you described, you could with a little know how make a decent looking box using 3/4" MDF and then just cover it in carpet.

[TinyGiant]

i've had good luck with MDF if you screw and glue chances are you wont have any issues

[talnlnky]

Originally Posted by TinyGiant

i've had good luck with MDF if you screw and glue chances are you wont have any issues

i challenge you to make a Baltic Birch box, and use Huricane Nuts for mounting the sub (found at http://www.parts-express.com/pe/show...umber=081-1082 ) and compare it to any MDF box you've ever made. You'll spend two to three times as much, but you'll instantly see the difference in quality. If done right... the box will last forever.... especially if you have it sprayed with LineX or Rhino-liner like I did with some boxes in the past.

[TinyGiant]

no doubt. I was just saying that if you have budgetary constraints... dont be afraid to use mdf.. its works well :)

[talnlnky]

Originally Posted by TinyGiant

no doubt. I was just saying that if you have budgetary constraints... dont be afraid to use mdf.. its works well :)

true... I would still recommend T nuts or Huricane nuts plus machine screws tho as they will clamp the sub in and hold it much tighter than any drywall screw ever could. In fact, you can get away with only doing 4 screws instead of the traditional 8, and they still hold tighter.

[H3LlIoN]

You guys missed what he was saying...he wants to put the box in the rear seat foot well, not the spare tire well.

I don't think anyone has done that. If it were me, I'd do the front panel and shape the sides out of MDF or BB, then use cloth to fiberglass the whole bottom to form fit the car. Finally, make face deck out of MDF/BB with cutouts for sub and amp displays plus supports, and rest it down on top of the fiberglass form. Finally, fiberglass it all together, paint, and put all the equipment in.

[H3LlIoN]

That's a lot of work for 1 sub though...are you sure you don't want 4?

[thewifesyaris]

Thanks for all of the replies everyone. Yes this is only for one sub. I plan on making a small box that correlates with the wooden cut out that will fill in the gap created by the removal of the rear seat. So think of the rear plastic piece that covers the spare, I will be working from this level and continuing it to just shy of the front seats, perhaps with a stopper of some sort closer to the front seats to prevent cargo from slipping into the smaller gab that will be left over when I am done.

So if you can picture it, I will have the spare, cover and carpet still intact with a piece of wood at the same level continuing from there to close to the backside of the front seats. With in this piece there will be a cut out where a 10 inch sub will protrude from in its own separate made box. This in theory will make the car look as if it was intended to be a two seater with a really large hatch/cargo area, with a sub enclosure.

My idea doesn't sound like too much work but I'll have to determine that later. I will use MDF like you all have suggested for the wood portion of the build. Of coarse I will post pictures when this all goes down. Just in homework mode.

[talnlnky]

Originally Posted by H3LlIoN

You guys missed what he was saying...he wants to put the box in the rear seat foot well, not the spare tire well.

I don't think anyone has done that. If it were me, I'd do the front panel and shape the sides out of MDF or BB, then use cloth to fiberglass the whole bottom to form fit the car. Finally, make face deck out of MDF/BB with cutouts for sub and amp displays plus supports, and rest it down on top of the fiberglass form. Finally, fiberglass it all together, paint, and put all the equipment in.

yeah, I understood.... the process will use similar techniques as if he were doing a spare tire install. I've seen custom truck boxes in the general shape that he'll be needing.

Since he only needs space for one sub... I'd just go with wood. less mess, much easier for a first time installer to work with, and much cheaper. Make the baffle (the top part that the sub mounts to double thickness... So, the baffle is 1.5" thick, and then have the sub sunken into it 3/4" so it is flush mounted and doesn't stick out. That way it'll be protected from cargo moving around.... you may even consider puting a heavy guage metal grate over the top of it too (has to be a heavy guage otherwise it'll resonate and sound horrible). If you go with a paint.... go with duplicolor bed liner... it dries hard, is bumpy (texture) and holds up fairly well to scratching. the texture will help hide any imperfections (but try your best cover up any imperfections with body filler before hand.