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Discussion Starter #1
How thick does aluminum need to be for a solid non-flexing baffle for 2 12" subs for infinite baffle? I read that aluminum is 3 times stronger, so could you technically use 1/4"?
 

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Thats assuming you feel 3/4" is enough for a wood baffle. I have never done it, but my gut says 1/2" would be minimum.
 

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Discussion Starter #3
Yeah, I think maybe 1/2" would be the equivalent of a double baffle. Maybe 1/4" aluminum and 3/4" wood layer would work.
 

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I have 1/4 Aluminum plate myself that I’ve used for various projects and if you made a sandwich with rubber between two 1/4” plates then you would have the ultimate non-resonating baffle. 1/4” thick Aluminum plate by itself is pretty stout.
 

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Aluminum is almost 4 times as dense as Baltic birch plywood so using 1.5” of plywood as a good comparison baffle, I’d suggest 3/8” aluminum as a minimum.
 

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Are you using aluminum for looks or to save space? Or just because you like aluminum like I do?!

How will you be cutting the holes? That might help determine what thickness or combination you should use, too...

What's your budget?
 

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Discussion Starter #7
looks are a big thought with aluminum. I have another idea also, but just did a bathroom remodel a few months ago and used aluminum for a shelf and I really liked how it looks. I would be cutting with a router.
 

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How thick does aluminum need to be for a solid non-flexing baffle for 2 12" subs for infinite baffle? I read that aluminum is 3 times stronger, so could you technically use 1/4"?
You need the modulates of stiffness, not the strength...
(They used wood in skis an SUV airplanes for a reason.)

The new the other thing is that the stiffness goes as the cube of the thickness. So if the modulus or elasticity were 3x, then thickness would be 0.52 (I think??)

Better off using 3/16" And then having some gusset/ stiffners welded on that stick up maybe in a 1/2-3/4" in a radial fashion.


I have 1/4 Aluminum plate myself that I’ve used for various projects and if you made a sandwich with rubber between two 1/4” plates then you would have the ultimate non-resonating baffle. 1/4” thick Aluminum plate by itself is pretty stout.
Back to skis...
Head used aluminium sandwiched over wood.
One could use 1/8" alloy over 3/8 of foam, which would be somewhat like a fibreglass boat hull with fibreglass over end grain balsa.
Or use endgrain balsa as the Core.
And the skis would often shove in some elastomer layer to control resonance.
 

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looks are a big thought with aluminum. I have another idea also, but just did a bathroom remodel a few months ago and used aluminum for a shelf and I really liked how it looks. I would be cutting with a router.

For looks, I would use plywood and a thin sheet of aluminum...


I have done that many times, including on my router lift table saw combo thingy (with stainless steel):



 

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Or get a price for a 1/2" sheet of aluminum large enough for two 12" subs and when you recover from the shock, buy a 3/4" sheet of plywood and a thin sheet of aluminum (which you could bond with contact adhesive like you would a veneer)... :)
 
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Looks like 4 times the density and 4 times the cost. I priced 1/2”x24”x48” and it cost almost $400 while I can get BB 3/4”x5’x5’ for $100.

 

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Discussion Starter #12

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Discussion Starter #13
1-Ported or 2-IB ?

Re - 3.245
Fs - 21.53
Qts - .4394
Qes - .4694
Qms - 6.875
Le - .2343
Vas - (not measured, factory has 203.9l)

Thoughts??
 

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Did you model them? I can model them with Bassbox Pro tomorrow if you want. Resonant frequency is low on those.
 
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From the world of diy aero, I suggest alumalite, as mentioned in this thread, thickness is the main factor in stiffness, so a composite core style material would be the most sensible. If feeling extra diy, I'd try for a balsa wood based core material sandwiched between 2 aluminum plates with full coverage of adhesive. If you wanna get super fancy, and invest in some tools you can use down the road, carbon fiber cloth isn't that expensive, once you have everything you need to use it. I think 1/4 of balsa core material with two layers of cf vacuum bags to each side would be decently stout, depending on baffle size, driver mounting orientation, and driver weight, whilst looking baller as fukk
 

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Discussion Starter #16
Did you model them? I can model them with Bassbox Pro tomorrow if you want. Resonant frequency is low on those.
I'm never been good at modeling ported enclosures (on built a couple in my life for others and both turned out really well).

So, I would really appreciate the modeling help. I forgot to list the XMAX, it is 14mm linear one-way, if you need that.
 

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Jerry, I need to agree with the others.

Make a birch baffle and cover with thinner aluminum trim. Just like most countertops and shelves. You'll save yourself fists full of cash.

If you feel the need to stick with billet aluminum then 1/4" seems a little thin. You may encounter resonances. Go with 3/8th" or better yet 1/2".

Also, how the heck would you cut this with a router? Curious. I wasn't aware a wide variety of metal bits existed. Also, how would you keep the bit lubricated / cool?

Ge0
 

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Discussion Starter #18
I have cut aluminum with a carbide tip wood bit but would probably take 20 passes or so to make it through 1/2” and not sure the bit would last...lol. I might be able to get it cut locally, but leaning toward my plan b now. Might combine your guys idea with my plan b.
 

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I have used 3 3/4" 11 plate birtch bultik.

Now I'm doing single single 18" and would need measurements of 19 1/2" x 40"

Wonder where I could get that and how much it would be to get the cut out going :)

Sent from my Pixel 4 XL using Tapatalk
 

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Jerry, I need to agree with the others.

Make a birch baffle and cover with thinner aluminum trim. Just like most countertops and shelves. You'll save yourself fists full of cash.

If you feel the need to stick with billet aluminum then 1/4" seems a little thin. You may encounter resonances. Go with 3/8th" or better yet 1/2".

Also, how the heck would you cut this with a router? Curious. I wasn't aware a wide variety of metal bits existed. Also, how would you keep the bit lubricated / cool?

Ge0
I have cut and shaped aluminum on a router with wood bits, only up to 1/4" though... Let's just say, it's not for the faint of heart!
 
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