Yup, the exploded version means many bends and fewer cut pieces to try and fit together. Tabs to tuck inside means this could be done rather quickly.
This baby looks straight forward and is scaled to a 20 x 30 foam core.
X, see if you could whip one up before dinner would ya?
https://www.google.ca/search?q=pape...dot.com%2Fpapercraft%3Adodecahedron;3202;2191
This baby looks straight forward and is scaled to a 20 x 30 foam core.
X, see if you could whip one up before dinner would ya?
https://www.google.ca/search?q=pape...dot.com%2Fpapercraft%3Adodecahedron;3202;2191
This one looks super simple and I would whip one up before dinner.... But alas... I am out of glue sticks and out of foam core
http://home.gwu.edu/~labrams/polyhedra/dodecahedron.pdf
http://home.gwu.edu/~labrams/polyhedra/dodecahedron.pdf
I've got foam core, and glue; hot, pva, super, lexal, and some weird not super from locktite. But only have 10 Vifa drivers right now. Just printed out in poster mode with cut marks to be able to paste together the sheets. 306% poster mode seems to print on a konica/minolta laser printer for a 22"X34" size on 4 11X17" sheets with ample margines, so that all of it will fit on a 20X30" foam core sheet.
Which faces should be the ones to leave blank at this time, using just 5 vifa drivers per speaker? I'll have to ponder this.
Or put 10 drivers in one speaker, and order another 10 later.
The WAF might be OK since I should be able to not use floor space.
The FIB did work, but did not have enough sound power for my family of old folks.
Which faces should be the ones to leave blank at this time, using just 5 vifa drivers per speaker? I'll have to ponder this.
Or put 10 drivers in one speaker, and order another 10 later.
The WAF might be OK since I should be able to not use floor space.
The FIB did work, but did not have enough sound power for my family of old folks.
Skip the top and bottom drivers: save the top for the suspension pendant and the bottom for a 12-driver BR port. Although the drivers are so high Qts that the BR volume would be prohibitively large - so a sealed alignment would be best. Good luck! Sounds like a lot of fun ahead tonight. Note that 10 Vifa's weighs quite a bit so the glue joints and panels need to be strong enough. Are you using the pdf plan in post 22?
Using the PDF from this post.
Wondering which size to use. I've got a fairly large one printed to 400% in which the distance from a vertex to face on the pentagrams is 6.6". And a much smaller one printed to 306% where the same vertex to face distance is just 5.1" Have to have room for the magnets inside, though the face of the speaker will be on the outside of two thicknesses of the foam core, which brings the magnet out quite a bit. Now which way to wire the things? It would be easier 9 speakers. The speaker could be wired to have an 8 ohm resistance, with three parallel strings of 3 series wired speakers.
Wondering which size to use. I've got a fairly large one printed to 400% in which the distance from a vertex to face on the pentagrams is 6.6". And a much smaller one printed to 306% where the same vertex to face distance is just 5.1" Have to have room for the magnets inside, though the face of the speaker will be on the outside of two thicknesses of the foam core, which brings the magnet out quite a bit. Now which way to wire the things? It would be easier 9 speakers. The speaker could be wired to have an 8 ohm resistance, with three parallel strings of 3 series wired speakers.
1 vote for extruded (six sided "cylinder") 2D hexagon omni. Just keep in mind that you will need to keep some distance to the back wall to not get the "first inklings" of cavity resonance.
You could do it like in your drawing with one or two drivers per side.
With the two drivers per side you could do a one speaker stereo thing, with three faces playing each side.
Could make for a very interesting speaker, suspended from the ceiling in a single wire.
It would be very easy to do in foamcore and because of the narrow pieces involved you wouldn't need that much extra bracing to get a result that is very close to, or as good as a ply cab.
The low weight would also make it easier to hang from any ceiling.
You could do it like in your drawing with one or two drivers per side.
With the two drivers per side you could do a one speaker stereo thing, with three faces playing each side.
Could make for a very interesting speaker, suspended from the ceiling in a single wire.
It would be very easy to do in foamcore and because of the narrow pieces involved you wouldn't need that much extra bracing to get a result that is very close to, or as good as a ply cab.
The low weight would also make it easier to hang from any ceiling.
well, I was about to do short open baffle line array, as pictured, because I like the sound of open baffle midrange, I do not like boxy sound...but truth is, most of my systems are open baffle, and I probably do not need another anymore, and I have line array too
that's why I liked the idea of exploring some Omni...even it will be in the box, so I may build one after all
that's why I liked the idea of exploring some Omni...even it will be in the box, so I may build one after all
Hi,
A tweeter aside a line array never works, and a line array aside
a bassmid never works either, unless locked into a rigid listening
position, been there done both, the latter rather expensive.
(Celestion 5000, 24" ribbon with an 8" bassmid, x/o @ 700Hz).
Not only that a short line array dies a death at frequencies
longer than its length, exacerbating any a lack of bass to
no real bass, and here the OB hump and roll-off will make
things even worse in terms of utterly no bass to speak off.
Nothing against trying anything, but even on the very cheap
I prefer some pragmatism to some hopeless overambition.
OB's are hardly what is being asked for in the original post.
rgds, sreten.
My original suggestion is not as flippant as it might first appear.
I've no idea whether sealed and well stuffed would work
or vented is possible, I suspect high Q and the former.
A tweeter aside a line array never works, and a line array aside
a bassmid never works either, unless locked into a rigid listening
position, been there done both, the latter rather expensive.
(Celestion 5000, 24" ribbon with an 8" bassmid, x/o @ 700Hz).
Not only that a short line array dies a death at frequencies
longer than its length, exacerbating any a lack of bass to
no real bass, and here the OB hump and roll-off will make
things even worse in terms of utterly no bass to speak off.
Nothing against trying anything, but even on the very cheap
I prefer some pragmatism to some hopeless overambition.
OB's are hardly what is being asked for in the original post.
rgds, sreten.
My original suggestion is not as flippant as it might first appear.
I've no idea whether sealed and well stuffed would work
or vented is possible, I suspect high Q and the former.
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I'm not a mathematician but I play one on TV so I'm having trouble grasping a hexagonal dodechahedron.
Hi,
Lets not get silly about practical shapes for a sphere, a cube
supported from a corner does a pretty good job, 6 drivers.
Cal shows there are many ways to slice a cucumber,
but its not a dodecahedron, it has too many faces.
From a cube with squares the next step up is pentagons :
And its a dodeca (12 faced) polyhedron., shown is the regular.
By polishing off the 20 vertices you get :
32 faces, again very regular.
Next up is the hexagon, but its clear it simply cannot form a sphere.
But if you take the above and expand the triangles until they merge
you get 20 hexagons and 12 pentagons, classic round ball pattern.
Again shown is regular. (There is something not right about
about my argument, seems to me, just a bit confused ....)
Yes, irregular hexagons can be used, but footballs always
use regular hexagons (and pentagons) optimally.
You can polish off the vertices of a cube
to get 14 faces 6 square and 8 triangular.
All assuming regular, its very complicated to describe but
not hard to visualise the possible options beyond that.
rgds, sreten.
Lets not get silly about practical shapes for a sphere, a cube
supported from a corner does a pretty good job, 6 drivers.
Cal shows there are many ways to slice a cucumber,
but its not a dodecahedron, it has too many faces.
From a cube with squares the next step up is pentagons :
And its a dodeca (12 faced) polyhedron., shown is the regular.
By polishing off the 20 vertices you get :
32 faces, again very regular.
Next up is the hexagon, but its clear it simply cannot form a sphere.
But if you take the above and expand the triangles until they merge
you get 20 hexagons and 12 pentagons, classic round ball pattern.
Again shown is regular. (There is something not right about
about my argument, seems to me, just a bit confused ....)
Yes, irregular hexagons can be used, but footballs always
use regular hexagons (and pentagons) optimally.
You can polish off the vertices of a cube
to get 14 faces 6 square and 8 triangular.
All assuming regular, its very complicated to describe but
not hard to visualise the possible options beyond that.
rgds, sreten.
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Next up is the hexagon, but its clear it simply cannot form a sphere.
But if you take the above and expand the triangles until they merge
you get 20 hexagons and 12 pentagons, classic round ball pattern.
Again shown is regular. (There is something not right about
about my argument, seems to me, just a bit confused ....)
Yes, irregular hexagons can be used, but footballs always
use regular hexagons (and pentagons) optimally.
Unless it is a CFL or NFL football
Divide the pents & the hexes ot the soccerbal; into triangles and you get a full geodestic sphere, i have 3/5 of one i made (~3ft diameter) in the garden.
dave
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I think that Planet10's suggestion of a 6-sided "cilinder" box should be quite doable. If possible you could have the side panels cut at 60 degrees so that they all flush fit, and a sturdy result. Then perhaps model some transmission line if feasible with these drivers, you could imagine the drivers being at ear level and a transmisison opening near the base (again if feasible with these drivers). Otherwise in a closed box.
I expect that such a cilindrical device can already give you a good omni character without being as complicated to make a a polyhedron.
An alternative could be to leave the back panel empty and put the remaining speaker on top. Or if you can get 2 extra speakers that you could apply (for 8 per box), then 1 on top and 2 at the back.
Interesting project !
I expect that such a cilindrical device can already give you a good omni character without being as complicated to make a a polyhedron.
An alternative could be to leave the back panel empty and put the remaining speaker on top. Or if you can get 2 extra speakers that you could apply (for 8 per box), then 1 on top and 2 at the back.
Interesting project !
Not me, but the OP showed a sketch of such. Cal built this shape cabinet, but mounted the drivers on the ends/
dave
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