I was wonderinf if 3/4" MDf is actually the best wood or the most practical due to the cost/performance. Would a harder wood like birch or oak be better? Y or Y not. I have access to extra wood so price is not the issue. Just seeing what u guys think.

 

Actually,the best for high powered sub enclosures is 5/8" HIGH density particle board because it is more dense and has less resonant qualities than MDF.It's inexpensive,but absorbs moisture and wears down saw blades quick. 3/4" MDF is really good also,but not quite as dense. It is easy to cut,but has a tendency to split when fastened with screws.When I build enclosures for customers,I put the pieces of wood together with Liquid Nails and use a pnuematic nail gun so the wood doesn't split.
Just remember,the higher the density,the better the enclosure will perform sonically because of limited flex in the enclosure walls.

 

particle board is nothing more than left over saw dust glue together. if you have a leak or any kind of moisture the particle board will soak it right up. i alsways use or insist on MDF simply because i dont want my box to become a sponge. hes right tho, particle board is cheaper.

daniel

 

so the higer desity, the better? what about wood like oak and birch? thanx

 

When ever i make a box, i drill pilot holes first. Then i put glue on the edges, line up the holes and power drive the screws in. No splits. Nails may be easier to use, but dont hold as well as screws. Maybe the pnuematic nails with the glue you use work better, but from home construction experience, nails seem to want to pull out after time.

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I like particle board because unlike real wood, it has no grain and it wont flex in any one direction more than another. Plus it is cheap... Heres my box
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True,nails do tend to pull apart.But I use 2 1/2" nails.And with the Liquid nails between the pieces to hold it together and seal it up,the box is not coming apart.I tried to pull one apart one time.Everything broke except for the joints.I can build a box like this in half the time it takes doing it with a screw gun. And as far as particle board being made of small pieces of wood and sawdust,true.But that's why I stated 5/8" HIGH-DENSITY particle board.It is pressed together under extremely high pressure and will not fall apart,leak air,or anything like that.Yes,it will soak up water,but so will MDF.Both will swell up if wet.But you're not putting it in a boat are you? If you think your car might have a leak and the box could somehow possibly get wet,then spray on some polyurethane or fiberglass resin.Simple enough. As far as birch,oak,etc.You can't find them in sheets like you can MDF,etc.So it would really not be worth it to join a lot of hardwood boards together to build a box.

[This message has been edited by RSpeed (edited December 03, 2000).]

 

Actually, I have access to the wood, my father is a superintendant for construction and I can literally get oak ect in sheets for free. I have learned HDF is good because it doesn't flex in specific points, but I do not think oak would flex at all. Just wondering if there was a specific reason MDF was used so often...i guess it was just cost....

 

Although hardwoods make great tables, they are not as well suited to box building as MDF. Although they are dense, they still have a much higher tendancy to resonate due to an inherant weakness and flexibility with any grain material. The Particle board is like a bunch of wood chips and glue smashed together under high pressure. MDF is like wood powder and glue that is pressed together under high pressure. Because of this, it exhibits very good rididity and resistance to vibration. Although hardwoods are very rigid, they are succeptable to vibration. Some of the finest home speaker enclosures in the world use MDF with a real wood laminate for appearance. Those that do use real wood have substantial internal bracing.

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i work in a home-depot-type place in the lumbner department, so i have seen a lot of different things. i also have built probably a dozen boxes for myslef and my friends.

here's my take on what to use...

use MDF for surface the speaker mounts to. it seems to hold the 8 screws that hold the speaker in better.

use a 3/4" HIGH DENSITY particle board for the rest of the box. this isn't regular particle board. it is called Nova Ply where i work. it is good stuff...really good stuff.

as far as teh water thing, i had my box in a leaky hatch for a while, and nothing at all happened to it. nothing. it was totally fine.

and, the prices for 3/4" MDF and 3/4" Nova Ply are really close. like 15 bucks a sheet up here in NY.

-brian

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A friend(and professional installer)who built the enclosure for my Formula uses 3/4" birch with great results. He's built boxes that actually gained a few db with birch as compared to MDF.

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