Diamond plate aluminum

[raintalk]

Hi Folks,

I've been thinking of putting together a box made of diamond plate aluminum. Since I have not tools for welding, I was thinking along the lines of a frame made of wood, and attach aluminum panels for the skin. Anybody done anything like this?
Have any pointers to working with aluminum?
I was thinking .125 thick, and add some bracing.

A few reasons.
* It looks cool. (IMO)
* Get the weight out. So I don't just want to wrap a wood box in diamond plate. I'd be looking for a neodymium driver to also cut some weight.
* Get the heat out. Let the heat inside the box escape through conduction on the panels.

thanks for any pointers

 

[lne937s]

In order to get the type of rigidity needed for a subwoofer box- flat panels of aluminum would be very heavy. The bracing would weigh more than the aluminum and you would probably be better off just using the aluminum as a skin on a traditional box. Flat aluminum on it's own is not very rigid until you get some significant thickness to it. I am using a 5/16" thick 1sq foot aluminum plate on an amp, and it still flexes somewhat and rings if you tap on it- very little dampening. The only aluminum subwoofer I've seen with flat sides used thick cast aluminum, weigh hundreds of pounds, and cost as much as a Korean car. Aluminum does gain rigidity when formed into a dome, sphere or tube shape. However, unless you have access to metalworking tools, this would be very dificult for you to do.

For light weight- try a sonotube. The shape of the tube makes the light weight possible.

 

[raintalk]

Thanks,

and Oooops - I should have added "durability"
Cardboard tubes aren't durable enough to haul around.

I'm thinking something like:
http://www.gallien-krueger.com/products_mb_ca_112.html#
Maybe something with a 15" driver.

I guess this isn't really a subwoofer, but I figured folks on this forum would know the most.

Looks like it's just not possible.

 

[Cal Weldon]

It's not impossible, it's just not very practical. Depite it being aluminum, it will still be heavy by the time you're done.

What do you want it for?

 

[raintalk]

Hmmm - the GK is only 12lbs. It's just expensive. And a little plain.

I want it for playing bass/drums through. Small clubs.
I'd leave it in the car as a sub for the stereo.

 

[Cal Weldon]

The GK is 0.1" thick with a 12"stamped driver. Of course it's light. It's also small so the extension can't be good and the thing probably vibrates like the dickens. Mind you it is endorsed by rock stars and we know how good their hearing is.

If you want to make it from diamond plate and then brace it, it will be heavy.

And very durable.

Cal

 

[raintalk]

If I used .125" diamond plate at 1.8lb per ft^2
I get about 28lbs for an enclosure say like this
http://www.partsexpress.com/pdf/290-594b.pdf

Add some bracing - seems like the weight wouldn't be too bad.

Hmmm - I wonder if some kind of cable could be used the stress the panels enough to hold down ringing (if it were bad enough)

 

[jdybnis]

sonotube can be durable if you wrap it in a second skin. Make the top and bottom plates square and 2" bigger than the tube's diameter. Use 1x1" square dowels between the plates to make a rectangular frame around the tube. Bracing every 12-18". Put a 1/4" ply skin (or some other material) on the frame.

 

[AnthonyPT]

Hi

For rigidity why not combine Paulownia panels
with aluminium as a laminate. An alternative
might be bamboo ply with the aluminium. Now
if you were designing a Ripol type sub with eg
18" Goldwoods you might save some
weight but I have found few subs with Neo
magnets that go low at reasonable prices.
The GOLDWOOD 18" GW-1858 weighs in at 11.4 lb
thats 5.2Kg with conventional magnet.
A 12" NEO is about 2kg FS 44hz here in OZ.
PAudio does some subs with Neo magnets too.
What sort of SPl are you looking for?
A couple of 18"ripols would be approx. 20"x20"x16"
each. Would they give enough SPL? Not sure !
If eq. was managed well should be clean!
Specifc gravity of Paulownia is 0.23 to 0.30.
Specific gravity of Aluminium 2.7

Regards

AnthonyPT

http://www.paulowniawood.com/
http://www.world-aluminium.org/production/processing/properties.html
http://www.tansu.com/wako/ew-030.htm
http://www.lautsprechershop.de/hifi/index.htm?/hifi/ripol.htm
Babelfish translates the german quite well!

 

[thespeakerguy]

Try it, and let us know!

It would be a different approach. Yes, the walls would resonate. Is that bad? You be the judge.

I have made speakers out of 1/4 inch acrylic. They work OK, but conventional wisdom says this should not be done

So much for conventional wisdom.

 

[AnthonyPT]

Hi

I was think more of a captive layer approach.
so Aluminium on inside and out. Often used in boats
and if you look at the Alu clad Ikea shelving.
Another option: The SG of Aluminium is 2.3 and that
of Eg. Cemlite lightweight concrete is 1.2 How about
Lightweight concrete between two aluminium panels?
USA must have similar light weight concrete like products.

Regards

AnthonyPT

http://www.abilityproducts.com.au/hot_cemlite.html

 

[raintalk]

Wow - Cemlite looks interesting, it'll be interesting to see if it can be used once it's available to the general public.

For a drivers. I can find a few potential neodymium drivers. The BMS drivers look interesting.
http://www.bmspro.info/index.php?show=item&usbid=10285&id=5047865

 

[DC Dave]

sonotube can be durable if you wrap it in a second skin. Make the top and bottom plates square and 2" bigger than the tube's diameter. Use 1x1" square dowels between the plates to make a rectangular frame around the tube. Bracing every 12-18". Put a 1/4" ply skin (or some other material) on the frame.

Working with this idea, use sonotube with square end-caps. Then attach four pieces of aluminum as the skin to the caps and some additional bracing. Fill the voids between the sonotube and the aluminum with expanding foam. Super durable and lite.

Edit: And it will float

 

[raintalk]

Ha - good idea.
but then I loose that heat transfer thing from the insulation. Maybe the end caps being aluminum would be good enough.

Sonotubes are going to make the position of the speaker a little funny. Up or down. And I have to depend on the floor for the sound. It's not really a sub, but a sub/mid

I do like that float part. I was playing a boat gig once when the boat rammed a dock. Everybody standing fell over. We didn't sink but it'd be nice to have something close to grab onto.

 

[ultrachrome]

and Oooops - I should have added "durability"
Cardboard tubes aren't durable enough to haul around.

If you size the cardboard tube similar to common drum sizes, you could use a padded corudura drum case to carry it around.

You could also double-wall the tube enclosure so that any exterior damage won't effect the enclosure integrity.

 

[jdybnis]

Not sure what you mean by only up or down. If you use square endcaps you can lay it down with the driver pointing any way you want.