Bu-jed-design. :) (1 Viewer)

[Jedd]

I tried to do everything as cheap as possible and here what I got:
Materials:
- Shiva 12" driver
- tube 12"x48"
- MDF 24"x24" cutted on four pieces 12"x12"
- plastic pipe 0.5"x92" cutted on two pieces 0.5x46"
- polyfill 3 pounds
- "piece of finish" 12"x12"
- sock for the tube
- grill
- wires&connectors

A - tube
B - MDF bottom endcap 12" radius, 1" thick, have a hole for the wires
C - MDF bottom stand 12"x12" (the only part you need to finish ), 1" thick, have a hole and bottom routing for the wires
D - 46" support struts, made of pvc pipe or wood
E - MDF ring, 11" inner radius, 12" outer radius (the hard part), 1" thick
Assembling:
- glue B into A, - fill A with a fiber, - glue D into A, - glue E into A (screw/glue to D), - screw driver to E, - put a sock on A, glue C to B, screw a grill to E, adjust wires and seal the hole in C
But it's all just a theory. I have no idea (yet), how to make a 1/2" MDF ring and how stable this whole structure will be.
Any comments?

 

[Bryan Michael]

the 1 inch ring wont be to easy to keep in 1 piecce here is what you do make the ring and glue it to a nother ring with the same iinside diamiter and make that ring over lap the tube and rought a gruve in the seccond piece of mdfb so the tube can sit in it like a 13 inch ring outsude diamiter that will make the botom alot stronger

 

[ThomasW]

Any comments?

Don't bother with the 'struts'

Use a larger diameter tube and give up on the really thin ring idea

Add the polyfill after everything but the driver is installed.

As designed it will be top heavy and subject to tipping over easily. Use a wider base.

 

[Jedd]

The cheapest tube of non 12" diametr I could find in my area is $97. And I have to travell Gods know where to pick it up. So I ended up with the 12" tube from HD. Maybe I should go with the smaller driver, but...

the 1 inch ring wont be to easy to keep in 1 piecce

So I wont try to keep it in 1 piece . I need it only to seal the space around the driver. I'm not sure if I really need MDF for this or I can replace it with the plywood or steel ring.

 

[ThomasW]

Not sure what is is about the right coast, lots of people complain about the tube pricing. In Denver the cost is about $4/ft

If you make an oversized top ring 14"-16" or so, that would work much better that trying to make a thin ring out of anything

 

[Dustin B]

Have you phoned any concrete contractors Jedd? My US geography isn't all that great, but Boston is a rather large place, no (or are you in some small suberb of Boston)? Either way there has to be a pile of concrete contractors in Boston that carry this stuff. Hell you might even find one that has a 30"-50" long chunk of 20"-24" tube that they would be willing to give away (since it would be too short for them to do anything with).

 

[Jedd]

Maybe it's just my bad luck, but I called about 10 concrete contractors/supply shops and only one of them had tubes sligtly under $100, the usual prices were $130-160. :frowning:
So, after that I told myself: "Hell, why to do it like everyone do?"
12"x48" tube available everywhere dirty cheap, it has PI ft^3 volume, which give us ~88L sealed enclosure. It is recommended sealed volume for Shiva - recommended by AdireAudio Shiva whitepapers.
The only missing part is how to seal it properly. (also watned benefits: lightweight, smallsize, practically no parts to gloss)
MDF cap from the one side seems to be inevitabe. So, the only questionable thing is how to seal the driver. And what material to use for that. It is very easy to seal it with the plywood or any other normal wood. But I lack the experience in the enclosure materials to tell if it's acceptable or not.

 

[ThomasW]

Jedd

You seal/glue the endcaps into the tube with siliconized acrylic caulking. It's cheaper than silicone seal and works well

You seal the woofer to the endcaps with closed cell foam tape.

BTW have you looked at any of the projects on TerryC's sonotube link? Patrick Sun has 3 projects that literally walk a person step by step through the process of making a tube sub. There are hundreds of pictures on his website

 

[Patrick Sun]

If you need to check out my Sunosub webpages, they are in my signature below: