Organic Enclosure Shapes: We need to talk.

[planet10]

and the baffles used:

An externally hosted image should be here but it was not working when we last tested it.

dave

 

[Bill F.]

Interesting how well the truncated pyramid measures. And I would have thought the cylinder with driver side-mounted would have measured better than it does...

 

[jan.didden]

I would expect that almost all shapes would do (much) better with the driver or exitation-hole mounted off-center. Was that addressed by Olson at all?

Jan Didden

 

[planet10]

Was that addressed by Olson at all?

Not in this study... he did do some baffle placement studies thou (the one the comes to mind is open baffle).

dave

 

[tiroth]

According to Rod Elliot placing the driver off center reduces the amplitude of some of the ripples but doesn't change the basic character. So, basically, optimize the baffle shape, then make final improvements via placement. Watch out for polar response changes in multiway systems though.

 

[planet10]

Except for exploring off-centre on an open-baffle (where dipole cancellation dominates) Olson doesn't seem to cover off on this subject.

With tools like the Edge or the FRD baffle simulator it would be pretty easy for someone to do a virtual study and give us some baseline. (i'm not doing it -- these tools only work in Windoz)

dave

 

[markp]

What about the egg? It's good enough for nature, is it good enough for us? How about placing a solid sphere in the center of a spherical cabinet to break up standing waves. Maybe an absorbent ball of fiberglass in the center would be even better.
Personally, I use rings of sonotube about 2" tall of different diameters glue to the larger panels of sub boxes. I lay them out in a random pattern and it makes the 3/4" mdf appear to be several inches thick without the weight. Try it, you'll like it! The sonotube is very rigid along the length and being a tube is self supporting.

 

[Artmaster]

nice diagram!

nice diagram! it's realy truth.
it means - form of box is not affect for low end range like 10Hz-100 hz
the same way as damping materials inside.
it's for voice range of wave. it's for 120Hz and higher. another business.
low wave have another biiiig, biiiig problem

 

[Mark25]

Diffraction: the ultimate guide.

APPLICATION OF THE GEOMETRIC THEORY OF DIFFRACTION (GTD) TO DIFFRACTION AT THE EDGES OF LOUDSPEAKER BAFFLES, R.M. Bews and M.O.J. Hawksford, JAES, vol.34, no.10, pp.771-779, October 1986

 

[markp]

Diffraction: the ultimate guide.

APPLICATION OF THE GEOMETRIC THEORY OF DIFFRACTION (GTD) TO DIFFRACTION AT THE EDGES OF LOUDSPEAKER BAFFLES, R.M. Bews and M.O.J. Hawksford, JAES, vol.34, no.10, pp.771-779, October 1986

That just deals with flat panels of different shapes. We are looking at 3-d shapes.

 

[Dinobe]

That's why Avalon uses a truncated pyramid for their speakers....

 

[ChowYunFett]

The original post of this thread mentions some DIY people that are into organic shapes but I couldn't find any thread actually dicussing how it is done best or what options you have to do it.
I'd like to build a small monitor box with a scan speak broadband chassis and I'd like to build an organic enclosure for it.

But little do I know... How is it done?

My first post here, hi guys

And thanks for any replies.

And sorry for bumping an anachronistic thread

 

[ChowYunFett]

B&W's got some interesting pics of nautilus enclosure preparation but I dont have too much insight on how they do it. Is that some kind of liquid ceramics the guy smears around the shape?

Or, while we're at it, what kind of cement or other mouldable material could you use to build a cabinet this way.

Nautilus cabinet moulding

Nautilus cabinet preparation

 

[kingdaddy]

Here is mine, there are some pictures of the construction that should give you the idea of how it was done.


http://kingdaddy.linaeum.com/Mains (SST-8)/