??? inside layer mdf outside layer birch

[jmkanek 10+ year member]

just wondering if anyone has built a box thats double layered with the inside layer being mdf with the outside being birch, just wondering if there would be any advantages of doing that

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[Johnny Law.Lulz 5,000+ posts]

I wouldnt see any advantages. People use Birch because its stronger and lighter, so weighing it down with MDF would be dumb. And if it was done, i think better results would be seen with the birch on the inside because its denser i believe.

 

[jmkanek 10+ year member]

just wondering tryin to save a few bucks, since mdf is about 20 bucks cheaper around here, box is going to be 13 cubic feet, so would it be better to save a lil more and just do 2 layers of birch.

 

[Johnny Law.Lulz 5,000+ posts]

just wondering tryin to save a few bucks, since mdf is about 20 bucks cheaper around here, box is going to be 13 cubic feet, so would it be better to save a lil more and just do 2 layers of birch.

I would do 2 layers of MDF. My 9.34 cubic foot box is double layered .75" MDF with no internal bracing what so ever and it will not flex. Period. you would be fine with 2 layers of .75", and you could do some bracing to make yourself feel better.

 

[jmkanek 10+ year member]

aight thanks man i plan on doing a small coat of fibergl*** on the inside of the box as well to strengthen it

 

[RAM_Designs 5,000+ posts]

And if it was done, i think better results would be seen with the birch on the inside because its denser i believe.

MDF is more dense, hence why it weighs more per sheet.

 

[Johnny Law.Lulz 5,000+ posts]

MDF is more dense, hence why it weighs more per sheet.

Makes sense. Its a little late here lol.

 

[Johnny Law.Lulz 5,000+ posts]

aight thanks man i plan on doing a small coat of fibergl*** on the inside of the box as well to strengthen it

Fibergl*** resin doesnt really add any strength unless your going to add matt and everything too IMO.

 

[KRYPTO 10+ year member]

So Birch is lighter and stronger, but will absorb some sound due to it not being as dense as MDF?

 

[Johnny Law.Lulz 5,000+ posts]

So Birch is lighter and stronger, but will absorb some sound due to it not being as dense as MDF?

Seems correct.

 

[KRYPTO 10+ year member]

So why would you want to use birch then? its more expensive and will take away some sound. You can just add bracing (or douple layer) on a MDF box to compensate for strength. Only thing left is weight being the benefit.

I'm just trying to understand box building more.

 

[jmkanek 10+ year member]

so what if ya use mdf for the inside to help keep the dense sound and put the birch outside for strength is i guess my main question how well thatd work

 

[audio-pro714 10+ year member]

Using mdf inside would b ideal for sound,birch on the outside would certainly help add mass to the mdf and reduce vibration if it was completely laminated with glue or adhesive to the mdf! If weight of the enclosure is not an issue?

 

[CHEMMINS 10+ year member]

Just resin the inside of the birch......it won't absorb your db's. One layer of 1" birch is the same strength as 2 layers of 3/4" mdf. That will be what I do. Cause 2 sheets of mdf is the same price as 1" birch, and the birch is less work, and lighter.

 

[basscort2009 5,000+ posts]

resin helps make a smoother surface and seal the seems for any air leaks. its not really used to add strength unless u use like 2 gallons like i do on my boxs lol