Lightest Sub Box Possible?

I want a small lightweight box.  I was considering building one mostly out of 1/2 MDF.  I am thinking of making a truck style single box, with the angle against the back of the seat and the driver mounted on the flat side facing the rear.  I am going to brace it and am considering coating the inside with fiberglass resin.  Right now I have a single Alumapro Alusonic 12" that needs 1.0 vol, but I will probably get a single 10" dual voice coil so that I can run the amp at 2 Ohms and get more power.  I am also considering fiberglass, but I spoke to someone who has exactly what I wanted in a single enclosure for my car, and his weighed about 35 pounds.  That seems awful heavy for that much trouble and my needs.  Any ideas would be great.

why are you that concerned about 35 pounds?      You do know a full tank of gass weights anywhere from 40-60 pounds?     if you concerned about how fast your gonna go vroom vroom,    maybe a system isnt for you.    I will tell you right now if you build a box of 3/4 MDF and build properly and dont use extra wood and fiberglass to weigh it down you will be just fine

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

Well depending on the vehicle, I'd recommend infinite baffle.  What you do is mount the subs in the rear deck of the car and the trunk acts as the enclosure.  That should offer you the "lightest" enclosure. 

If you are looking for an actual enclosure, then fiberglass will offer you the best strength to weight ratio.  Next would be using plywood.  Plywood is lighter than MDF but just as strong.

Steven Kephart

Adire Audio

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i know that if you ar eusing plywood, you have to be really careful to pick good piece and watch for knots, when drilling ends of plywood, the plys can com apart if you aren't on point with the drilling. I recommend fiberglass, cause it's the lightest. Just make the enclosure really curvy, you'll need less layers to re-enforce the flat areas, if there aren't any. they also make a much more expensive MDF that weighs a lot less, I  forgot what it's called.

I would recommend what Steven said. Use the trunk as the enclosure. No added weight there, except the sub of course :) .

Now, if you want to make a regular enclosure, I would recommend either Fiberglass or Furniture Grade Plywood

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Thanks for the ideas.  I am considering everything I can.  I have had nice systems in my cars for the last 13+ years.  I thought I could get by with stock set up, but it isn't going to happen.  I am just putting together a small, light, simple set up that would provide great sound.

If you're thinking of replacing your subwoofer anyway, why not shoot for a 10" or something that works in a .5-.7ft^3 box. That should cut down on the weight even if you do use 3/4" mdf. Many car audio manufacturers are starting to make subwoofers intended for small enclosure use.

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New Project: 2003 Pathfinder

Are you a stock car driver???   What's 35 pounds?    I like my boxes big and heavy....it's harder for the guy who steals it to run down the street with...

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~WAYLAND

Nice Wayland....I know that even if you manage to get in my trunk. the struggle you will put forth to try and get the box out will set off the alarm

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

Tell me about ur box....  I got 5 cubic feet of box, with two 20 pound woofers inside.   No handles (just two ports).  The thing weighs at least 110 pounds,  and is the most awkward thing to carry (stretch out your arms....it's that long).  You'd need two men just to carry it.  Never mind getting it out the side doors either,  it doesn't fit.  You can only slide it out the rear, which is why i always back my truck up against a telephone pole or somehting... 

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~WAYLAND

(4) 10 inch eclipse alum's   1.6 cu ft per sub after port displacement.    the box had to be fully assembled in the car without the seats in it.   Its a civic coupe!   in order to get the box out you have to remove all the panels and the rear seat to get it inot the cab. then take the side boards off to seperate it into 2 boxes to get it out the doors! haha    now thats hard to jack.   the subs are helo in with allen head screws to stop from just taking the subs.    they would probably destroy them before taking them

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

Haha,  Niiiiiice...   I went the security screw route...  Rounded head Torx Screws,  with a button in the center....

https://www.hudsonfasteners.com/security.htm

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~WAYLAND

i shouldnt continue on with the topic of screws. but the thought of them has given me an idea to have my brother make a set or 2 for my sub when its installed.
i could ask him to design a screw head with its own driver bit so noone would have anything remotely nere mine.

thanks guys for that brain-fart, it was enjoyable.

i dont think adding just resin to the inside of the sub box will do much but maybe help seal it. fiberglas ony works when you do resin and glass (no reason you coudnt do a layer or 2 of 1.5 oz mat on the inside of a 1/2" mdf box. couldnt hurt. glass is really only that stong in curves tho, not strait flat pieces. good luck, lets see pics when its done. ~Ryan

I don't know if anyone has mention'd this before, but there is a lighter type of wood that can be used for speaker building.

It is basically MDF board, but lighter it looks like a very light white. I forgot where I read about it, but it's about half the weight of MDF, but more expensive.

I'd look into that if you are concerned with the weight.