GM JX92S MLTL-48 from a D160mm drainpipe?

[tib]

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?

[rjbond3rd]

Cool idea! The sand is a great idea. That should be a very solid cab.

[Colin]

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.

[tib]

Originally Posted by Colin

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.

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.

[Colin]

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.

[Scottmoose]

Originally Posted by tib

I would attach the driver to the side of the pipe, not the top.

Pluto is a (semi) omnidirectional design, rather than a regular direct-radiator so the upward-firing unit is part of the design. Goes with the turf. I don't think anyone here is proposing the same in this particular case.

[tib]

Originally Posted by Colin

The trouble with that approach would be that it would constrict the pipe to almost half the area, around the driver.

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".

Originally Posted by Colin

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.

This D shape from wood is a nice idea!

[Colin]

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.

[chrisb]

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/projec...son/index.html

[Colin]

Oh, I can see that being allowed in the lounge ...