[Audio Empire]

On Thu, 19 Jul 2012 04:04:21 -0700, Dick Pierce wrote
(in article ):

Audio Empire wrote:
On Wed, 18 Jul 2012 05:45:18 -0700, Arny Krueger wrote
(in article ):

"Barkingspyder" wrote in message
...

Based on what I have read here if I'm going to use Sonotube, it would be
very wise to find some way to brace it internally.

Not exactly rocket science. Get a bunch of 2x2 clear pine, some 3 1/2"
dry
wall screws, a 1/8" drill, and some construction adhesive.

Your knuckles and ears are probably your best tools.


Possibly, there is some other brand of tubing that would be thicker and
possibly more rigid.

Unlikely. This stuff is built for a different purpose (concrete forms),
and
it is entirely adequate if not overbuilt for that purpose.

What's wrong with ceramic (or concrete) pipe or chimney flue liners?
They're
cheap, unbelievably stiff and easy to find.

From the viewpoint of stiffness and mass and availability,
they're probably okay. One problem is that their internal
losses are low, which means any mechanical resonances that
might get started are goign to hang around for a while.

They're also not the easiest material to work with.



I found just the opposite to be true. You need to make a couple of endcaps
out of 3/4" plywood and affix them to the pipe using threaded rods (makes a
sandwich. Wooden end-caps (one with woofer, one with port) and the pipe
essentially squeezed between them by the threaded rods). Paint the pipe (or
leave it natural clay color) and you have it made.