Sub Box Design / Help

[szmidi 10+ year member]

I plan on having it under black car carpet anyways. I want it to look as much an original part of the car as a few thousand watts and subwoofers can look. I'm not into the high gloss fibreglass painted to match the outside of the car or something. I can make some more inquiries into the birch but I think its just there is no one local I can deal with and its a bit hard to find on ebay how thick would the birch need to be?

 

[disturbed471985 5,000+ posts]

3/4" is what I would go with its twice as strong as mdf but half the weight of mdf.

http://www.ebay.com/itm/Baltic-Birch-Plywood-1-PC-3-4-X-30-X-30-/170213725861?pt=LH_DefaultDomain_0&hash=item27a18756a5

 

[szmidi 10+ year member]

I think Birch might be a Northern hemisphere thing. The more places I ring up about it, the more I hear 'we can't get it'.

Best I have found is this from a home stereo forum - Austral Plywoods - Products - Acoustic

Either that or back to the fibreglass idea.....can anyone help with those questions I had????

 

[duanebro 10+ year member]

I think Birch might be a Northern hemisphere thing. The more places I ring up about it, the more I hear 'we can't get it'.
Best I have found is this from a home stereo forum - Austral Plywoods - Products - Acoustic

Either that or back to the fibreglass idea.....can anyone help with those questions I had????

Look at that web page and check out Marine Grade Plywood. Or call them and ask about void free plywood. 13 ply void free is what you want, that is normally the baltic birch here in the states, they will have something like it that will be fine. Note that plywood is not as dense as MDF and should be braced a bit more do to that.

 

[duanebro 10+ year member]

This is what you want:

Austral Plywoods - Products - Multiply

 

[szmidi 10+ year member]

It is telling you to do 3 cubic feet for both together? If you are doing sealed, I would not do a shared chamber box. I would add a piece that cuts the box in half, which will also add strength. If you are going ported, also just build one big box, but they can share the same chamber...
Either way, since you are saving space, it makes no sense to build 2 separate boxes.

Thanks all for your help. After some designing and research into materials I've got things sorts.

One more questions. If I use this seperator to technically make two sealed boxes, how do I calculate the size of the port between them?

 

[duanebro 10+ year member]

Thanks all for your help. After some designing and research into materials I've got things sorts.
One more questions. If I use this seperator to technically make two sealed boxes, how do I calculate the size of the port between them?

there is no port, it is just two sealed boxes.

 

[szmidi 10+ year member]

there is no port, it is just two sealed boxes.

Ok no problem. Thanks a lot.

 

[Cook107 10+ year member]

It's cubic ft. Not squared. And second of all, you cant have a box be sealed AND ported unless you're talking band pass. And if you dont know how to fiberglass, don't start with a box. You need to learn a little more before you build a box. Especially from fiberglass. If its not completely square then you aren't getting the CUBIC ft that you want. Which throws off tuning. Designing a box is very in depth and if you haven't done it before its really hard. I'd pay a designer on here to design it, use mdf, and use beauty pieces(sheets of wood that mount to box and fill the spaces between box and wall.) then carpet just the beauty pieces. Boom. Done.

 

[ssteele18 10+ year member]

I think Birch might be a Northern hemisphere thing. The more places I ring up about it, the more I hear 'we can't get it'.
Best I have found is this from a home stereo forum - Austral Plywoods - Products - Acoustic

Either that or back to the fibreglass idea.....can anyone help with those questions I had????

It's cubic ft. Not squared. And second of all, you cant have a box be sealed AND ported unless you're talking band pass. And if you dont know how to fiberglass, don't start with a box. You need to learn a little more before you build a box. Especially from fiberglass. If its not completely square then you aren't getting the CUBIC ft that you want. Which throws off tuning. Designing a box is very in depth and if you haven't done it before its really hard. I'd pay a designer on here to design it, use mdf, and use beauty pieces(sheets of wood that mount to box and fill the spaces between box and wall.) then carpet just the beauty pieces. Boom. Done.

Let's not kill his hopes and dreams just yet.. lol

First of all, you obviously like the idea of fiberglass. So I'd suggest you read up on it. home

He isn't a professional, but because of that, you'll get alot of the "First major steps" that the pros omit on their Do It Yourself videos.

Second, figure out what you want. Do you want sealed or ported? Usually you can work out a decent size box tuned to the desired frequency. If you aren't sure about frequency. Google it. lol

Third, once you've finally decided on what you want, go with it. Everytime you are about to try something new its best to try to TEST it on something else first(i.e. router bit on scrap plywood).

Any other questions?