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pd298
07-25-2005, 09:56 PM
Is plywood a good type of wood to construct a sealed box for 2 12" subs?

iceteebone
07-25-2005, 09:58 PM
no. medium density fiberboard, aka mdf

pd298
07-25-2005, 10:00 PM
So plywood is not an option?

94CamryBumpin
07-25-2005, 10:01 PM
not a very good one...

AndyB
07-25-2005, 10:02 PM
If you would like it to fall apart, it is a great idea. :veryhapp:

pd298
07-25-2005, 10:53 PM
no. medium density fiberboard, aka mdf
So can I just get this at any lumber yard? Along with woodglue and screws?

DragonCub
07-25-2005, 10:55 PM
Home Depot carries MDF.

SPL140.2
07-25-2005, 10:56 PM
Plywood will flex under pressure, go with the .75" MDF or if your lumber yard doesnt carry it use High Density Particle Board <--- just dont let it get wet or it will swell.

jacko
07-25-2005, 10:56 PM
No, lumberyards are completely against screws and glue. They feel it's harmful and heartless to ever harm the wood with glue and screws. I highly doubt they would carry products like that.

creater
07-25-2005, 10:56 PM
just go into home depot and you should be fine mang...

most fine lumber yards should sell it

JimJ
07-25-2005, 10:56 PM
Lot of wacky info in this thread.

True void-free, cabinet grade 3/4" ply is excellent material for speaker enclosures. However, at $45 a sheet it's more than double what MDF costs. So it's a value question, not a structural one. But if you properly brace the enclosure, baltic birch or similar furniture grade plywood is primo stuff - if you afford the price tag.

Prowler573
07-25-2005, 11:03 PM
True void-free, cabinet grade 3/4" ply is excellent material for speaker enclosures. However, at $45 a sheet it's more than double what MDF costs. So it's a value question, not a structural one. But if you properly brace the enclosure, baltic birch or similar furniture grade plywood is primo stuff - if you afford the price tag.

Agreed. :)

However, you'll find the majority of perfectly acceptable quality enclosures are built out of MDF. Dollar for dollar it makes a much better box than comparably priced plywood. Can you use normal, everyday CDX-grade ply? Yep. You sure can. :) Would that $15~$18/sheet be better applied buying MDF? Yep. Sure would. :)

jacko
07-25-2005, 11:05 PM
Let us know when it's done, post pics, let us know how those pioneers sound.

ss3079
07-25-2005, 11:07 PM
Lot of wacky info in this thread.

True void-free, cabinet grade 3/4" ply is excellent material for speaker enclosures. However, at $45 a sheet it's more than double what MDF costs. So it's a value question, not a structural one. But if you properly brace the enclosure, baltic birch or similar furniture grade plywood is primo stuff - if you afford the price tag.

:)

pd298
07-25-2005, 11:09 PM
alright, well my grandpa is helping me with the project, he is more experienced with wood working. He told me 1/4-1/2 inch plywood (most likely ill be getting 1/2), finished on both sides. and to get 6 two-by-twos that are 6 or 8 feet long to brace the box.. and of course, wood glue and screws... Im not really sure on what he plans on doing with the two-by-twos. SO you guys think I will be safe?

ss3079
07-25-2005, 11:11 PM
alright, well my grandpa is helping me with the project, he is more experienced with wood working. He told me 1/4-1/2 inch plywood (most likely ill be getting 1/2), finished on both sides. and to get 6 two-by-twos that are 6 or 8 feet long to brace the box.. and of course, wood glue and screws... Im not really sure on what he plans on doing with the two-by-twos. SO you guys think I will be safe?

2x2's would likely be for bracing.

I'd just save your money and go for the the 3/4" MDF and be done with it.

'Good-on-both-sides' furniture grade plywood isn't cheap at all.

jacko
07-25-2005, 11:11 PM
He may be an expirenced woodworker and your lucky he's helping you, however I don't know if he fully understands how much pressure is inside of a sub box at times, I know my grandpa wouldn't, but maybe he does, no clue. go 3/4 inch.

stones
07-25-2005, 11:14 PM
Interesting story.
I met a guy who had a dual 10" enclosure built entirely out of chromed diamond plate sheet metal welded together, it looked awsome but sounded awful, nasty resonance.

pd298
07-25-2005, 11:23 PM
Interesting story.
I met a guy who had a dual 10" enclosure built entirely out of chromed diamond plate sheet metal welded together, it looked awsome but sounded awful, nasty resonance.
Thats a little off topic dont you think? I will call him tommorow and ask him about the MDF..so if i get mdf....I need 3/4"? How much does that usually run? And, I asked this earlier but I didnt get a clear answer...Does a lumberyard carry mdf?

jacko
07-25-2005, 11:27 PM
#1- call your local lumberyard for that answer, it's most likely in the phone book under lumber yards or building supplies

#2- Sheet of MDF is typically around $20 give or take a few dollars

stones
07-25-2005, 11:30 PM
I asked this earlier but I didnt get a clear answer...Does a lumberyard carry mdf?

Think about that really really hard-
Lumber yards carry wooden building supplies.
MDF is a wooden building material.

Now think real hard about about this.

pd298
07-25-2005, 11:36 PM
Think about that really really hard-
Lumber yards carry wooden building supplies.
MDF is a wooden building material.

Now think real hard about about this.
You sir are an idiot. Get out of my thread if you can't answer my question maturely

Jtsky
07-25-2005, 11:36 PM
I am just curious here. Would 1" mdf be better if you are using a lot of power? At what point would that be necesary?

pd298
07-25-2005, 11:38 PM
I am only pushing 725 watts, so I dont think I would need to have 1". is 3/4 what I need?

stones
07-25-2005, 11:38 PM
You sir are an idiot. Get out of my thread if you can't answer my question maturely
You're the one who doesn't know what MDF is :rolleyes: . :p:

JimJ
07-25-2005, 11:39 PM
Would 1" mdf be better if you are using a lot of power?

Would be a lot better. The SPL guys often use MDF in layers to stiffen up the enclosure.


At what point would that be necesary?

When your current enclosure is flexing too much and robbing you of dB's :)


You sir are an idiot. Get out of my thread if you can't answer my question maturely

He might have come across a little harsh, but his point was correct. And it was previously answered in the thread by other posters.

pd298
07-25-2005, 11:39 PM
In what way does that mean I am an idiot? All that is showing is that my knowledge of building boxes is limited.

ss3079
07-25-2005, 11:40 PM
Get back on topic or it'll be closed. Pretty simple.

pd298
07-25-2005, 11:46 PM
so 3/4 mdf?

ss3079
07-25-2005, 11:46 PM
so 3/4 mdf?

Will work fine.

iceteebone
07-25-2005, 11:47 PM
is there a home depot whitin your area? if so they will for sure have it and it will cost you about $20. i live in a ****** little town with no more then 900 people and the crappy little 2-bit lumberyard here has 3/4" mdf.

ighettoboyi
07-25-2005, 11:47 PM
For The Last Time! Yesssss!!!!!!!!!!

SPL140.2
07-25-2005, 11:55 PM
This is for all the tech guys and may help with choosing:
Below are some typical values for the modulus of elasticity (in million pounds per square inch) and density (in pounds per cubic feet) for MDF, Oak, Pine and Fir Plywood.

Material
MOE
Density

MDF
0.53
48

Oak
1.55
38

Pine
1.3
29

Fir Plywood
1.2
33


The modulus of elasticity (MOE), also called Young's modulus, is the ratio of stress to strain, where stress is the force per unit area placed on the item and strain is the deformation caused by the stress. The MOE is therefore a measure of stiffness.

Q: Can I build speakers with {MDF | particle board | plywood | solid wood}?

A: You can build speakers with whatever you like ! However, MDF is often the material of choice. Its stiffness and density yield good accoustical damping properties. Particle board and plywood are cheaper and can still be used if cost is an issue. Plywood (especially if void free) can be used in the main baffle as a sandwich material to better hold fasteners. Plywood is also a good material for making braces inside speaker boxes. Solid wood (lumber) suffers from movement - the swelling and shrinking of wood due to environmental changes such as humidity - and is therefore not a good material for speaker enclosures. Lumber is also not as acoustically dead as MDF.

There are times however, when plywood, particle board and other common sheet goods are more than suitable for enclosures. Such possible uses include sound reinforcement, musical instrument cabinets, and PA systems.


this came from http://www.bscaust.com/THE%20MDF%20FAQ.htm ;)

pd298
07-26-2005, 12:00 AM
is there a home depot whitin your area? if so they will for sure have it and it will cost you about $20. i live in a ****** little town with no more then 900 people and the crappy little 2-bit lumberyard here has 3/4" mdf.
No there isnt..Its about 30 mins away..




This is for all the tech guys and may help with choosing:
Below are some typical values for the modulus of elasticity (in million pounds per square inch) and density (in pounds per cubic feet) for MDF, Oak, Pine and Fir Plywood.

Material
MOE
Density

MDF
0.53
48

Oak
1.55
38

Pine
1.3
29

Fir Plywood
1.2
33


The modulus of elasticity (MOE), also called Young's modulus, is the ratio of stress to strain, where stress is the force per unit area placed on the item and strain is the deformation caused by the stress. The MOE is therefore a measure of stiffness.

Q: Can I build speakers with {MDF | particle board | plywood | solid wood}?

A: You can build speakers with whatever you like ! However, MDF is often the material of choice. Its stiffness and density yield good accoustical damping properties. Particle board and plywood are cheaper and can still be used if cost is an issue. Plywood (especially if void free) can be used in the main baffle as a sandwich material to better hold fasteners. Plywood is also a good material for making braces inside speaker boxes. Solid wood (lumber) suffers from movement - the swelling and shrinking of wood due to environmental changes such as humidity - and is therefore not a good material for speaker enclosures. Lumber is also not as acoustically dead as MDF.

There are times however, when plywood, particle board and other common sheet goods are more than suitable for enclosures. Such possible uses include sound reinforcement, musical instrument cabinets, and PA systems.


this came from http://www.bscaust.com/THE%20MDF%20FAQ.htm ;)
Thanks for that information

TeenWolf
07-26-2005, 12:03 AM
Interesting story.
I met a guy who had a dual 10" enclosure built entirely out of chromed diamond plate sheet metal welded together, it looked awsome but sounded awful, nasty resonance.

That's crazy!!

SPL140.2
07-26-2005, 12:08 AM
No there isnt..Its about 30 mins away..




Thanks for that information

welcome ;)

fo0manchu
07-26-2005, 03:06 AM
This is for all the tech guys and may help with choosing:
Below are some typical values for the modulus of elasticity (in million pounds per square inch) and density (in pounds per cubic feet) for MDF, Oak, Pine and Fir Plywood.

Material
MOE
Density

MDF
0.53
48

Oak
1.55
38

Pine
1.3
29

Fir Plywood
1.2
33


The modulus of elasticity (MOE), also called Young's modulus, is the ratio of stress to strain, where stress is the force per unit area placed on the item and strain is the deformation caused by the stress. The MOE is therefore a measure of stiffness.

Q: Can I build speakers with {MDF | particle board | plywood | solid wood}?

A: You can build speakers with whatever you like ! However, MDF is often the material of choice. Its stiffness and density yield good accoustical damping properties. Particle board and plywood are cheaper and can still be used if cost is an issue. Plywood (especially if void free) can be used in the main baffle as a sandwich material to better hold fasteners. Plywood is also a good material for making braces inside speaker boxes. Solid wood (lumber) suffers from movement - the swelling and shrinking of wood due to environmental changes such as humidity - and is therefore not a good material for speaker enclosures. Lumber is also not as acoustically dead as MDF.

There are times however, when plywood, particle board and other common sheet goods are more than suitable for enclosures. Such possible uses include sound reinforcement, musical instrument cabinets, and PA systems.


this came from http://www.bscaust.com/THE%20MDF%20FAQ.htm ;)


AMEN!! Now go get the MDF for the last time and close this thread already! :D