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Discussion Starter #1
Here is the start of the box, first layer .75 MDF. Experimenting with new bracing, 3/8 allthread with a washer and nut on each side of the wood.

 

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Discussion Starter #4
Looking at a metal conductivity chart, silver, copper, gold and pure aluminum are the best conductors in that order. Not satisfied with speaker connectors available commercially, most are gold plated, only a few microns thick. I tried to find solid copper connectors, could not find them anywhere. My dad is a mechanical engineer who is basically a mad scientist. I asked him if he knew where to get solid copper bolts. He asked what size and how long I needed them and he made them for me. They are made out of oxygen free copper. They are 5/16 bolts that are long enough for the triple walled subwoofer cabinet.

 

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Discussion Starter #5
Here is how it will be secured. Most aluminum is an alloy, not as good of a conductor as pure aluminum. He was able to find pure aluminum nuts. I purchased copper ring terminals and copper washers to hold everything together..

 

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Now that's what I would call dotting all the I's and crossing the T's on a build! Talk about attention to detail. Maybe you and your father should go into the subwoofer business together. :D For sure nobody else is going to match that.
 

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Discussion Starter #7
Forgot to mention, the box weighs 110 lbs. There is no way I could ever make money on this. I'd lose all my money on shipping the beast.
 

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Forgot to mention, the box weighs 110 lbs. There is no way I could ever make money on this. I'd lose all my money on shipping the beast.
Charge your customers for shipping? :T
 

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Just for future reference Cardas makes solid billet copper binding posts: http://www.soniccraft.com/products/connections/bindingpost/cardas.htm

Vampire does as well: http://www.soniccraft.com/products/connections/bindingpost/vampire_bphexcb.htm

The Cardas you can get in just copper or gold plated copper so that it doesn't oxidize. The Vampire only comes gold plated copper.

I use these Vampire binding posts all the time: http://www.soniccraft.com/products/connections/bindingpost/vampire_bp15hex.htm
Not copper but gold plated brass on all my sub builds and the quality is near the top of the best I have used for not a lot of money, they actually use to be a lot cheaper when I bought a bunch in bulk.
 

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Discussion Starter #10
I saw the Cardas solid copper binding posts, but even the long ones were too short, .21 of an inch too short. The bolts I have are oxygen free copper at .3125" in diameter. The copper binding posts are smaller in diameter at .265".

He made 12 for me so I can hookup six speakers. Six of the solid copper cardas binding posts would have cost $168 and that's not including shipping.
 

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I was just responding to this:

Looking at a metal conductivity chart, silver, copper, gold and pure aluminum are the best conductors in that order. Not satisfied with speaker connectors available commercially, most are gold plated, only a few microns thick. I tried to find solid copper connectors, could not find them anywhere. My dad is a mechanical engineer who is basically a mad scientist. I asked him if he knew where to get solid copper bolts. He asked what size and how long I needed them and he made them for me. They are made out of oxygen free copper. They are 5/16 bolts that are long enough for the triple walled subwoofer cabinet.
That is why I said for future reference for anyone who might be reading this, the rest of us are out of luck that don't happen to have a super smart mechanical engineer for a Dad :)

I would of course use your copper bolts if I had access to them, unfortunately I don't.
 

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Discussion Starter #12
Sorry I meant to say, none that would fit my application.

Let me know what size, diameter and how many you want and I can ask him how much he would charge.
 

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Great looking box.

Out of curiosity, what made you choose to go with all thread for bracing?

As a mechanical engineer myself, I think using strips of wood would be more cost effective and easier to use.
 

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Sorry I meant to say, none that would fit my application.

Let me know what size, diameter and how many you want and I can ask him how much he would charge.
I appreciate the offer, I just ordered a bunch of binding posts though so I am good for about 20 builds.
 

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Discussion Starter #15
Great looking box.

Out of curiosity, what made you choose to go with all thread for bracing?

As a mechanical engineer myself, I think using strips of wood would be more cost effective and easier to use.
I wanted to try the allthread as an experiment. I've never seen it done before and wanted to see if it worked. I think there are pros and cons to each bracing method.

Here is my favorite bracing I've done, but also the hardest to implement. Everything interlocks.

 

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Discussion Starter #17
Here is my least favorite method of bracing. 1/2 inch hardwood dowels. The dowels were inset to the wood with a forstner bit. They didn't deaden the walls enough for the trouble it was worth. This was a double layer box.



 

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I have tried the dowel method to brace as well but got much better results like you with the interlocking method:



Would love to do a concrete walled enclosure or even an aluminum enclosure one day.
 

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Discussion Starter #19
I've looked into concrete, but it scares me. Building the box with paver stones was really easy, the only problem is they are heavy. The box I made was .7 cu foot and it was over 80 lbs. At my local store I can get 24 x 24 paver stones so you could easily make a large box for a subwoofer. The only problem is it would be super heavy. I'm guessing 200-300 lbs.
 

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Discussion Starter #20
Hooked it up today and watched a couple movies. This thing sounds awesome, definitely the loudest so far. Here is a video....

 
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