What Do You Think . . . and How Does It Work?

Schedule 40/6" is 7mm thick. Schedule 80 is 11mm thick. I am rusty on my structural eng.

Cylinders echo and gain? ... no, they behave pretty much like any other "tube" whether it is square or rectangular, but more consistent and easier to deal with.

All materials "ring". If you have a material that does not ring (at all), then it is probably not stiff (or only stiff in one dimension). You can always add dampening. Open the hood of your car and knock on the likely aluminum block. Tell me if it "rings".

This design gets the benefits of a spherical design, but also adds a tapered tube at the back to eliminate all internal resonances.

Shape Variation
Cube +-5.0 db
Rectangle +-3.0 db
Cylinder +-2.0 db
Beveled Cube +-1.5 db
Beveled Rectangle +-1.5 db
Sphere +-0.5 db

Interesting, for a complete speaker system, round. smooth, tapered interiors, are a way to reduce pocket resonance. It can also be used to incorporate a resonance into an enclosure also.. That was my point, the GAIN factor, for BASS is a real issue for distortion in the bass region 250hz<

You have to use it or lose it, but you can't keep it.. 

When speaking of spectral decay effects on enclosure vs mechanical distortion (GAIN based) there is no comparison in how much one increases over the other. (The 20% bass distortion crowd, and don't even know it)
Interiors that are rough inside, not smooth are a much quieter enclosure.. The SQ is always better..

Remove the Highlands Scottish wool from behind the mids, let that blister your ears a bit..
or Remove the VERY coarse fiberglass from the bass enclosure...
BOOM....forever........

INSIDE, Smooth is bad.
OUTSIDE, Smooth is good, but just for the dust factor.
if it wasn't for that rough would be better.

Regards

I think it’s generally agreed in the industry that a box is the worst possible shape for a loudspeaker cabinet.

The main reasons why most are built this way seems to be consumer expectations of domestic acceptability and manufacturing convenience.

yep. We are being duped. Most audiophiles dont want to hear that though. Even ATC use box shapes and yet they are regarded as the finest speakers. It is all a hoax. 

The industry? Good grief!

The whole reason for OB, right, boundaries, and boxes are not the first choice, of a seasoned speaker builder.
I’m not a commercial speaker builder, seasoned, oh yea..

I build what I know works, for over 45 years, now. The 120 to 130 pairs, I’ve put out...Not a round one in the bunch. Though I did do an underground concrete vault one time.. that is still working fine.. 1/2 ton

OB Lattice structure, with ribbon and planar drivers are my thing.

NO BOX, NO TUBE, it’s not round, event the driver openings are rectangle, not round...

Time to go feed the chickens.. and George... the goat. and  Junior the rabbit, and  Bubs the dog.


Regards..