I'm just about to order a pair of JX92S. I'm wondering which enclosure design should should I build for it.
I guess GM's MLTL-48 will be the winner, and since it's cross-section shape may vary until its area remain unchanged I have calculated that its equal to a D=157mm cylindrical shape.
So I have a crazy idea to build it from a D160mm drainpipe like this: The Blanchford Group 6" Underground.
What is your opinion? (If the port tube can be made from plastic... 😉 )
Does this circular shape has some benefits over the rectangular or triangular one?
Maybe it would still require a box around the pipe, the voids filled with sand?
I guess GM's MLTL-48 will be the winner, and since it's cross-section shape may vary until its area remain unchanged I have calculated that its equal to a D=157mm cylindrical shape.
So I have a crazy idea to build it from a D160mm drainpipe like this: The Blanchford Group 6" Underground.
What is your opinion? (If the port tube can be made from plastic... 😉 )
Does this circular shape has some benefits over the rectangular or triangular one?
Maybe it would still require a box around the pipe, the voids filled with sand?
A pipe is fine, a good strong structure. I looked at something similar (a cardboard former used in the paper industry) but the problem is mounting the driver into the curved pipe. A small section of coupling pipe? Would that introduce a cavity resonance? In the end the complication put me off but I'd be introduced to see what solution you arrive at.
Linkwitz uses a pipe section for his Pluto design - Pluto introduction
Given the stiffness of the cylinder shape, the extra sand/box section shouldn't be necessary.
Linkwitz uses a pipe section for his Pluto design - Pluto introduction
Given the stiffness of the cylinder shape, the extra sand/box section shouldn't be necessary.
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I would attach the driver to the side of the pipe, not the top.
And since it is made of plastic with some heating and pushing from inside a mounting plane could be crated for the driver.
The trouble with that approach would be that it would constrict the pipe to almost half the area, around the driver.
I decided that the formers I found would be more useful as a central core to mould thin ply or bending-mdf around to create a D-shape cross-section out of wood. Add a flat baffle, then remove the core and cap off the ends. Failing that, I'm still on the lookout for a suitable aluminium or steel extrusion the right area and shape.
BTW, in case anyone is interested; the paper formers are the cores at the centre of large rolls of paper. They are about a quarter inch thick, up to four feet long and very solid. Most paper mills throw them away or give them to schools for craft projects. They'll usually give them away free. Cheaper than sonotubes from the construction industry but limited to about six inches diameter.
I decided that the formers I found would be more useful as a central core to mould thin ply or bending-mdf around to create a D-shape cross-section out of wood. Add a flat baffle, then remove the core and cap off the ends. Failing that, I'm still on the lookout for a suitable aluminium or steel extrusion the right area and shape.
BTW, in case anyone is interested; the paper formers are the cores at the centre of large rolls of paper. They are about a quarter inch thick, up to four feet long and very solid. Most paper mills throw them away or give them to schools for craft projects. They'll usually give them away free. Cheaper than sonotubes from the construction industry but limited to about six inches diameter.
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That is why I said: push the pipe from inside -> it will have an increased area at the driver mounting point.
T-Shape pipe connectors are also available, however I can not imagine the effect made by this little side tube... Maybe MJK would be able to model it... 🙂
One more possibility: use a corner connector at one end of the pipe and put the driver there. But again this needs a different design than MLTL 48".
This D shape from wood is a nice idea!
Of course if you can get a large enough diameter plastic tube, you could just slice out a strip along the length and install a baffle. I did see some nice yellow tubes being used by the local water company but didn't get round to asking if they had any spare lengths.
most plastic pipe products have elbow, T- junction & adapter fittings that should allow for easier install of driver(s), pretty much at your choice of location
http://www.t-linespeakers.org/projects/sampson/index.html
http://www.t-linespeakers.org/projects/sampson/index.html
An externally hosted image should be here but it was not working when we last tested it.
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Hi there: I once needed some circular PVC tubes, so I gentley heated the pipes with a burns torch, and bent them around a bicycle rim. So it is likely that using incrementally larger blocks of wood as hand formers inside the pipe, heating the pipe gently from the out side and as "TIB" suggested in posts #4 & 7, pressing the pipe from the inside out to a flat spot would work. I have a piece of 4-inch diameter PVC pipe left over from an OB experiment, I may try this out. Another solution would be to bend the pipe tp a 90 degree elbow and mount the driver in the end (Such "sweep elbows" are available for PVC conduit for the electrical trade, however I do not know the diameters available.) ... regards, Michael
Neatform MDF would work for the D-shape enclosure if making it for wood. Not easy to find suppliers (in the UK) but here is one which gives the general idea of the shape it is capable of being formed into:
D3UK - Bendy MDF
And the manufacturer's site is here
Innovative Panel Products by Neat Concepts
Not too expensive, either, although you would need to double up on the wall thickness.
D3UK - Bendy MDF
And the manufacturer's site is here
Innovative Panel Products by Neat Concepts
Not too expensive, either, although you would need to double up on the wall thickness.
I'v just went to a store to see and touch these plastic pipes.
They are available in 110, 125, 160, 200, 250, 315, 400, 500 mm diameter (at least in Hungary).
http://www.pestan.net/pdf/pestan-kg-pipes-and-fitings.pdf
Before invest money in them it would be good to know if they resonating and having "plastic tube voice" or not.
An other problem can be: they are not as nice looking as the wood.
I also has found bendable MDF and polywood:
http://www.bohacs.eu/feltoltott/retegelthajl.jpg
http://www.bohacs.eu/feltoltott/MDFhajl.jpg
- I'll check these next week.
If their bending radius is small enough then there is two way to utilize them:
1) They could be put in a normal rectangular box to make a D shape around the driver -> this will reduce the reflexions in the box. (The voids in the two corner could be filled with sand...)
2) Glue them directly to the front baffle to get the D shape. In this case I'm not sure if the glue is strong enough and also these woods are a bit thin, so 2-3 layer would be needed...
They are available in 110, 125, 160, 200, 250, 315, 400, 500 mm diameter (at least in Hungary).
http://www.pestan.net/pdf/pestan-kg-pipes-and-fitings.pdf
Before invest money in them it would be good to know if they resonating and having "plastic tube voice" or not.
An other problem can be: they are not as nice looking as the wood.
I also has found bendable MDF and polywood:
http://www.bohacs.eu/feltoltott/retegelthajl.jpg
http://www.bohacs.eu/feltoltott/MDFhajl.jpg
- I'll check these next week.
If their bending radius is small enough then there is two way to utilize them:
1) They could be put in a normal rectangular box to make a D shape around the driver -> this will reduce the reflexions in the box. (The voids in the two corner could be filled with sand...)
2) Glue them directly to the front baffle to get the D shape. In this case I'm not sure if the glue is strong enough and also these woods are a bit thin, so 2-3 layer would be needed...
Sonotubes might be your best bet (or piling tubes as they're called in the UK). Cut a section out along the length and install a wooden baffle. You could cover the cardboard tube with a leatherette material and use a decent ply for the front.
UK suppliers here, for anyone interested
Cardboard Tubes Essex Tube Windings Manufacturer
UK suppliers here, for anyone interested
Cardboard Tubes Essex Tube Windings Manufacturer
Essex tubes quoted £65 plus VAT for a 205 x 2400 mm tube, delivered in the UK. 6-8mm cardboard or fibreboard wall suitable for loudspeaker use. The tubes are also used for fabricating DIY telescopes, apparently.
The 205mm tube with a section cut out to make it 205 x 125 mm deep is about the right cross-sectional area for GM's MLTL, either the 31" or 48" (ugh, mixing measurements - this thread will never reach Mars). One tube for a pair. Doesn't sound too costly and with the right finish could be made to look rather Bang & Olufsen.
The 205mm tube with a section cut out to make it 205 x 125 mm deep is about the right cross-sectional area for GM's MLTL, either the 31" or 48" (ugh, mixing measurements - this thread will never reach Mars). One tube for a pair. Doesn't sound too costly and with the right finish could be made to look rather Bang & Olufsen.
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