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Oh and yes.. 1/2" is bad. You want 3/4" for a subwoofer unless you will double wall.
Doesn't this depend on what type of sub is in question?
 

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Doesn't this depend on what type of sub is in question?
It depends on a lot of things. I am assuming most common 18" drivers as a marty sub- since this is the marty FAQ thread :p

If you wanted to use 1/2" you would really want to pay attention to your bracing, or double up. Any wall flex, cabinet resonance, and the like is all lost output. You don't want that. Thicker is better for a sub generally speaking- it's got less flex. I also find it a lot easier to work with 3/4" because you have a lot more meat to hit with a screw or a brad nail. 1/2" does not give you a big bullseye, and if you are not careful you can easily come out of the sides. Not so bad when it's inside the box, but it's extra pain when it's outside. These are things better left not done IMO, 3/4" is much easier for a beginner. It's also got more surface area for glue- so likely stronger there too. I feel like you can get away with less bracing using the 3/4" material and not get into trouble so it's actually easier and faster to use 3/4". It weighs more. That can be good thing too. The cost is only a couple bucks more for 3/4" versus 1/2"- the difference in cost per sheet isn't prohibitive.
 

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It depends on a lot of things. I am assuming most common 18" drivers as a marty sub- since this is the marty FAQ thread

If you wanted to use 1/2" you would really want to pay attention to your bracing, or double up. Any wall flex, cabinet resonance, and the like is all lost output. You don't want that. Thicker is better for a sub generally speaking- it's got less flex. I also find it a lot easier to work with 3/4" because you have a lot more meat to hit with a screw or a brad nail. 1/2" does not give you a big bullseye, and if you are not careful you can easily come out of the sides. Not so bad when it's inside the box, but it's extra pain when it's outside. These are things better left not done IMO, 3/4" is much easier for a beginner. It's also got more surface area for glue- so likely stronger there too. I feel like you can get away with less bracing using the 3/4" material and not get into trouble so it's actually easier and faster to use 3/4". It weighs more. That can be good thing too. The cost is only a couple bucks more for 3/4" versus 1/2"- the difference in cost per sheet isn't prohibitive.
Ahh. Forgot this was a Marty thread lol.
 

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I actually used 1/2" MDF for my sealed DO Marty, but I also made sure to brace it well... I ended up tripling the baffles since I needed to recess them, though I didn't triple them their whole height. So the top and sides are 1/2", as is all the bracing, the baffles are 1" on the bottom and 1 1/2" around the driver. Since my design was dual opposed, I didn't need the box to be heavy just to be stable, and figured why not try to make it lighter.

Frankly, though, I'm not sure it was worth the trouble, as it would've been easier to build with fewer braces,any I'd bet any difference in weight is probably minimal at best. I'll probably just stick to 3/4" for future builds.

 

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I actually used 1/2" MDF for my sealed DO Marty, but I also made sure to brace it well... I ended up tripling the baffles since I needed to recess them, though I didn't triple them their whole height. So the top and sides are 1/2", as is all the bracing, the baffles are 1" on the bottom and 1 1/2" around the driver. Since my design was dual opposed, I didn't need the box to be heavy just to be stable, and figured why not try to make it lighter.

Frankly, though, I'm not sure it was worth the trouble, as it would've been easier to build with fewer braces,any I'd bet any difference in weight is probably minimal at best. I'll probably just stick to 3/4" for future builds.


Haha.. that's silly @rhodesj. I like it. ^ :D Triple baffle- double wall- and a crap ton of braces. Well done.

They say a picture is worth a thousand words. That's it right there. That basically shows what I meant about 1/2" vs 3/4". You end up not needing to double up so much, or use quite as much bracing with the thicker sheet goods so in many ways it's easier to work with. Of coarse- 1/2 + 1/2 = 1" which is more than 3/4- so that's cool and certainly works well if you want to go that way.

More to your point- I also like to double up on the 3/4" face- so I can recess the woofer mounting. You don't have enough meat or thickness to go routing off some unless you double up. You still end up with a good amount of wood to drive screws into if you double up. (or in your case triple up)





 

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Looks solid rhodesj

Those small pieces are there just for the woofer screws to bite into right...

I may run braces to the back of the box at those points,two birds right.
 

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You don't need ultra light. Unless you think you do. It's a weight thing. I am of the general belief the heavier stuff is probably better. Density and weight are good things with subwoofer boxes generally- it might move less or be more stable. The heavier probably has a lower resonance too, or better damping. I honestly don't think it's a big deal one way or the other but just food for thought- nothing wrong with using the heavy stuff. Especially if you are on a budget, or it's what is most available to you. You just need to deal with the fact it's troublesome to move around alone. Have them cut it in half at the store for you. Makes it a bit more manageable.
Ultralight is cheaper and much easier to work with. You dont get the disgusting amount of dust and it measures and sounds the same for a sub as regular mdf. Unfortunately its not available in the USA as much as Canada.
 

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Ultralight is cheaper and much easier to work with. You dont get the disgusting amount of dust and it measures and sounds the same for a sub as regular mdf. Unfortunately its not available in the USA as much as Canada.
Both my local yard and my local HD don't carry it. I wish they did. I think just being able to handle a full sheet myself without help would be worth it. I can handle a ply sheet alone, but not MDF.

"disgusting amount of dust"

um...

Basically...

Yeah.

Exactly.
 

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Both my local yard and my local HD don't carry it. I wish they did. I think just being able to handle a full sheet myself without help would be worth it. I can handle a ply sheet alone, but not MDF.

"disgusting amount of dust"

um...

Basically...

Yeah.

Exactly.
Only downside of ultralight is you cant skimp on bracing. Need it every 8" or so. Windsor plywood is the big canadian retailer who carries it and for 3/4 " mdf the ultralight outsells regular 5 to 1. It weighs virtually the same as plywood.
 

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Only downside of ultralight is you cant skimp on bracing. Need it every 8" or so. Windsor plywood is the big canadian retailer who carries it and for 3/4 " mdf the ultralight outsells regular 5 to 1. It weighs virtually the same as plywood.
Same concept as using the thinner material like 1/2" or weaker wood like a cheap ply. Close up the distance of your braces. +1. I agree for sure, you are right on the money.

Just like DIY audio is about compromises, there is compromises with wood too. That was a little of what I was saying earlier there is a lot of hate on the heavy normal 3/4 MDF but it's cheap, available and it works. I wouldn't be afraid to use it if it's all you have available, and only if you are intolerable of it's dust or weight is there a real reason to avoid it. From a quality of the project results perspective, or a sound quality perspective the stuff is rather good. It just isn't fun to work with. If you want to do some extra bracing you can use thinner, or different- or pay a big premium for BB. Any of the solutions can get your a nice subwoofer box if you do it right. I'm a little jealous of your ultra light :)
 

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help with driver cutout

Maybe a dumb question but what do you guys using to trace the cutout diameter on the front baffle ? I went to home depot to try to find a large compas without success



Alain
 

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Maybe a dumb question but what do you guys using to trace the cutout diameter on the front baffle ? I went to home depot to try to find a large compas without success
You have lots of options. From the simple like a nail, a piece of scrap wood, and a pencil taped to the side of the wood as a compass. To the expensive, but near flawless router with a circle jig.
 

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You have lots of options. From the simple like a nail, a piece of scrap wood, and a pencil taped to the side of the wood as a compass. To the expensive, but near flawless router with a circle jig.
Should have tought of it

tHanks a lot for your reply
 

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I actually used 1/2" MDF for my sealed DO Marty, but I also made sure to brace it well... I ended up tripling the baffles since I needed to recess them, though I didn't triple them their whole height. So the top and sides are 1/2", as is all the bracing, the baffles are 1" on the bottom and 1 1/2" around the driver. Since my design was dual opposed, I didn't need the box to be heavy just to be stable, and figured why not try to make it lighter.

Frankly, though, I'm not sure it was worth the trouble, as it would've been easier to build with fewer braces,any I'd bet any difference in weight is probably minimal at best. I'll probably just stick to 3/4" for future builds.

What size of drive hole you cut .. sorry stupid question, but I ordered driver which wont come up till end of May and was planning to build a cube before driver comes .... restless and excited for my first build
 

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What size of drive hole you cut .. sorry stupid question, but I ordered driver which wont come up till end of May and was planning to build a cube before driver comes .... restless and excited for my first build
That would entirely depend on which driver you ordered... ;)

The manufacturers typically have the dimensions on their web site.
 
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