I have a pair of 45 degree pipe enclosures - heavy ceramic. Interior diameter
is 12". Yours free - come and collect, Kensington London. 020-7602-2707

I had absolutely great results with some heavy concrete 45 degree angles I used
in Norway. They were presumably sewerage pipes that were extra robust to endure
freezing. One of the cleanest sounds I ever had. Totally inert and no standing
waves.


=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

Andy Evans wrote:

I have a pair of 45 degree pipe enclosures - heavy ceramic. Interior
diameter is 12". Yours free - come and collect, Kensington London.
020-7602-2707

Unfortunately, I fear the cost of collecting from Scotland might be a tad
more expensive than sourcing locally. :-) And 12" is a bit big - looking
for something to suit a KEF B110, so nearer half that diameter would be
better.


I had absolutely great results with some heavy concrete 45 degree
angles I used in Norway. They were presumably sewerage pipes that
were extra robust to endure freezing. One of the cleanest sounds I
ever had. Totally inert and no standing waves.

Good to hear - this bodes well.


--
Wally
www.art-gallery.myby.co.uk
Moving soon to: www.artbywally.com

Andy Evans wrote:

I have a pair of 45 degree pipe enclosures - heavy ceramic. Interior
diameter is 12". Yours free - come and collect, Kensington London.
020-7602-2707

Unfortunately, I fear the cost of collecting from Scotland might be a tad
more expensive than sourcing locally. :-) And 12" is a bit big - looking
for something to suit a KEF B110, so nearer half that diameter would be
better.


I had absolutely great results with some heavy concrete 45 degree
angles I used in Norway. They were presumably sewerage pipes that
were extra robust to endure freezing. One of the cleanest sounds I
ever had. Totally inert and no standing waves.

Good to hear - this bodes well.


--
Wally
www.art-gallery.myby.co.uk
Moving soon to: www.artbywally.com

On 13 Jan 2004 16:28:39 GMT, Andy Evans
wrote:

I have a pair of 45 degree pipe enclosures - heavy ceramic. Interior
diameter
is 12". Yours free - come and collect, Kensington London. 020-7602-2707

I had absolutely great results with some heavy concrete 45 degree angles
I used
in Norway. They were presumably sewerage pipes that were extra robust to
endure
freezing. One of the cleanest sounds I ever had. Totally inert and no
standing
waves.

To me sewage pipes sound a little unnecessary.
Sonotube is just thick cardboard, but because of it's tubular construction
can stand the
weight of being filled with concrete without flexing to make pilars for
buildings. I doubt
*any* driver puts as much pressure on the tube as a ton of concrete.

Quoting from the article I posted:

Q: How thick does the tube have to be ? It looks too thin to be effective !

A: The tube walls don't have to be very thick at all. Sonotube walls are
usually no more 1/4 inch thick. Their shape provide amazing shape - more
than enough to hold the weight of concrete without deforming.

Doug Purl posted the following on the DIY Loudspeaker list on
12-January-2001 :

"Once again a thread on tubes as speaker enclosures has appeared. And once
again all the posters have been laboring under a misapprehension of how
the thing works. Folks, the walls don't flex. You don't have to lard them
up with damping. It is precisely the reason that pipes conducting fluids
and gasses under pressure are round and not square.

If you stood inside a garbage can and pushed your arms outwards the walls
would flex. But if you had an infinite number of arms and pushed outwards
equally at every point, the can would not flex. The net effect would be to
try to stretch the walls rather than bend them.

Boxes flex because their panels have different resistance to flexure at
different points. Tubes have the same resistance to flexure at every
point, and receive identical pressure at every point."

--
Jim H jh
@333
.org

On 13 Jan 2004 16:28:39 GMT, Andy Evans
wrote:

I have a pair of 45 degree pipe enclosures - heavy ceramic. Interior
diameter
is 12". Yours free - come and collect, Kensington London. 020-7602-2707

I had absolutely great results with some heavy concrete 45 degree angles
I used
in Norway. They were presumably sewerage pipes that were extra robust to
endure
freezing. One of the cleanest sounds I ever had. Totally inert and no
standing
waves.

To me sewage pipes sound a little unnecessary.
Sonotube is just thick cardboard, but because of it's tubular construction
can stand the
weight of being filled with concrete without flexing to make pilars for
buildings. I doubt
*any* driver puts as much pressure on the tube as a ton of concrete.

Quoting from the article I posted:

Q: How thick does the tube have to be ? It looks too thin to be effective !

A: The tube walls don't have to be very thick at all. Sonotube walls are
usually no more 1/4 inch thick. Their shape provide amazing shape - more
than enough to hold the weight of concrete without deforming.

Doug Purl posted the following on the DIY Loudspeaker list on
12-January-2001 :

"Once again a thread on tubes as speaker enclosures has appeared. And once
again all the posters have been laboring under a misapprehension of how
the thing works. Folks, the walls don't flex. You don't have to lard them
up with damping. It is precisely the reason that pipes conducting fluids
and gasses under pressure are round and not square.

If you stood inside a garbage can and pushed your arms outwards the walls
would flex. But if you had an infinite number of arms and pushed outwards
equally at every point, the can would not flex. The net effect would be to
try to stretch the walls rather than bend them.

Boxes flex because their panels have different resistance to flexure at
different points. Tubes have the same resistance to flexure at every
point, and receive identical pressure at every point."

--
Jim H jh
@333
.org

On Tue, 13 Jan 2004 16:07:03 -0000, Wally wrote:

Jim H wrote:

This might interest:
http://www.lungster.com/l/speakers/sonotubefaq.html

Indeed - cheers.

Nicely finished they look not too shabby too.

see http://www.surfnetusa.com/sho/BassPix/4-5.JPG for example

--
Jim H jh
@333
.org

On Tue, 13 Jan 2004 16:07:03 -0000, Wally wrote:

Jim H wrote:

This might interest:
http://www.lungster.com/l/speakers/sonotubefaq.html

Indeed - cheers.

Nicely finished they look not too shabby too.

see http://www.surfnetusa.com/sho/BassPix/4-5.JPG for example

--
Jim H jh
@333
.org

On Tue, 13 Jan 2004 15:16:59 -0000, "Wally"
wrote:

Slightly off the wall, but bear with me...

Whatever subs I end up with, there will come a time when the large 3-way
boxes I'm using at present will no longer contain bass drivers and will be
replaced. The replacement cabs will likely use the existing KEF B110 and T27
drivers.

I'd like the small cabs to be as free of possible resonances and similar
effects as is feasible. To this end, those Nautilus snail shell thingies
have interesting enclosures for the mid-range drivers - very non-box-shaped,
and there's no baffle board.

Assuming I'm able to fabricate an enclosure of this type, would the general
principle of a cylindrical cab with a rounded interior shape and no baffle
work well with my drivers?

Please note that the Nautili do *not* use a cylindrical midrange
enclosure, it's diffraction characteristics are much closer to those
of a sphere. See the classic Olsen plots from the '50s to see the
difference this makes.

If so, what materials might be suitable? I
envisage a volume of around 8 litres, rough outer dimensions being 150mm
diameter and 300mm or so long. So far, I've considered the following
construction approaches...

Cut a series of rings out of MDF, glue them together to create a tapered
cylinder, then work them to get a smooth surface.

Mould the cabinets out of GRP. Could there be resonances with this approach?
If thickness will reduce them, how thick would be good enough? 10-12mm?

Make them out of some sort of resinous paste, perhaps using wire
reinforcement for the main structure and metal plates for fitting points.
How about car body filler for this approach? If not, what other paste-type
materials are worth looking at?

KEF used commercial fishing floats for the 'Eureka' project in the
'70s. Alternatively, why not use concrete? It's easily moulded onto a
chicken wire armature, and very rigid.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 13 Jan 2004 16:05:08 -0000, "Wally"
wrote:

Don Pearce wrote:

There was a design recommended by Wharfedale back in the sixties that
used a concrete drain pipe for exactly the purpose you describe. I'm
sure that with a little searching round the bigger plumbers you could
find something suitable.

I remember something like that (with the driver mounted in the side rather
than on the end). I'll be having a wander round the local DIY to check out
their audiophile-quality garden ornaments...

The Wharfedale design used the driver mounted vertically in the end of
the pipe, with a conical reflector suspended above it.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 13 Jan 2004 16:05:08 -0000, "Wally"
wrote:

Don Pearce wrote:

There was a design recommended by Wharfedale back in the sixties that
used a concrete drain pipe for exactly the purpose you describe. I'm
sure that with a little searching round the bigger plumbers you could
find something suitable.

I remember something like that (with the driver mounted in the side rather
than on the end). I'll be having a wander round the local DIY to check out
their audiophile-quality garden ornaments...

The Wharfedale design used the driver mounted vertically in the end of
the pipe, with a conical reflector suspended above it.
--

Stewart Pinkerton | Music is Art - Audio is Engineering