I've been working on some waveguide/horns a la geddes for some months now. I started by casting a new throat into some parts express 12" waveguides and creating a conical section until the tangential point of the original flare and the fitted-in OS flare...... then I decided to go bigger, adding a wooden ring to extend the conical section and backfilling to create a cone. I then shaped a foam ring to create the mouth flare and wrapped in plaster cloth, affixed and filled. Then resin coating after resin coating after.... after.... after...
Suffice it to say, months of coating and sanding and I'm still not done. Getting close and they're extremely nice, but in retrospect, I should have quit either with the OS short section fitted to the PE 12, done wooden horns, or done a fiberglass layup from scratch.
Suffice it to say, months of coating and sanding and I'm still not done. Getting close and they're extremely nice, but in retrospect, I should have quit either with the OS short section fitted to the PE 12, done wooden horns, or done a fiberglass layup from scratch.
No criticisms on the rather hash job, but it works! Only worked out how to wrap around the ends once all the 14 pieces were in place, so it is a bit bodged.
Definitely a cheap method. I choose 740Hz for 1" driver as it cut outs fit on a sheet of A4. 14 petals.
Cheap Eminence APT80 without its flare.
Sounds pretty good, considering its got some holes in it.
Heres the planar cut with 4 on A4 paper if anyone wants to give it a whirl (total length 264.7mm incase it scales up or down):
http://dl.dropbox.com/u/1444609/diyaudio/Le%20Cleac%27h%20horn%201%22%2C%20740Hz.jpg
Definitely a cheap method. I choose 740Hz for 1" driver as it cut outs fit on a sheet of A4. 14 petals.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Cheap Eminence APT80 without its flare.
An externally hosted image should be here but it was not working when we last tested it.
Sounds pretty good, considering its got some holes in it.
Heres the planar cut with 4 on A4 paper if anyone wants to give it a whirl (total length 264.7mm incase it scales up or down):
http://dl.dropbox.com/u/1444609/diyaudio/Le%20Cleac%27h%20horn%201%22%2C%20740Hz.jpg
Hello Studio Au,
Congratulations! Your "flower like" horn looks good.
There is only a minor thing to improve: the very last ripple in the petal coutour corresponds to the part of the profile over 360° (opening angle) and so that part should be curved forward and not backward as seen on a profile picture you shown to us.
(that's another reason why you have holes between petals...)
Best regards from Paris, France
Congratulations! Your "flower like" horn looks good.
There is only a minor thing to improve: the very last ripple in the petal coutour corresponds to the part of the profile over 360° (opening angle) and so that part should be curved forward and not backward as seen on a profile picture you shown to us.
(that's another reason why you have holes between petals...)
Best regards from Paris, France
(this site seems to blow up pics i take on my iPhone, apologies)
So the petal leaf, essentially it doubles back on itself? thats what it looked like on the profile on the spreadsheet.
Does this affect the curve as it is? It seemed impossible for it to follow the edges as it contorts it in too many ways.
So the petal leaf, essentially it doubles back on itself? thats what it looked like on the profile on the spreadsheet.
Does this affect the curve as it is? It seemed impossible for it to follow the edges as it contorts it in too many ways.
On my printer
Got about 260mm length with borders removed and scaled up to 131%. Should be close enough. I have some APT80s floating around so this may be a good supertweeter horn for the OS guides that peter out at 10k.
how are you getting the tape applied cleanly? The quick tests I've done were anything but easy.
Got about 260mm length with borders removed and scaled up to 131%. Should be close enough. I have some APT80s floating around so this may be a good supertweeter horn for the OS guides that peter out at 10k.
how are you getting the tape applied cleanly? The quick tests I've done were anything but easy.
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Glad to see there is less ruminating and more working!
The tapes on the back. for some reason the front seemed the most logical. Didn't work. I might smooth some plaster on top tomorrow, fill the gaps and reduce the throat size to fit the APT's better.
What i found best was to place a long strip of masking tape over half a petals length (so it overhangs), snip the masking tape into a few sections so it can 'lay flat' when the petals curl. And then attach the next petal (with masking tape process repeated)
I started to add tabs, but not so great, perhaps lots and then staple it?
I still don't know how to resolve the curling ends.
Jean-Michell I modled a square, 4 sided horn for a cheap 8" (18cm) full range I have.
What should the output angle of compression driver be?
Can you explain what on earth happens with all these ripples and how im meant to glue them? For mock up sake, can i include the first curl and disregard the rest?
Thanks for your invaluable help.
The tapes on the back. for some reason the front seemed the most logical. Didn't work. I might smooth some plaster on top tomorrow, fill the gaps and reduce the throat size to fit the APT's better.
What i found best was to place a long strip of masking tape over half a petals length (so it overhangs), snip the masking tape into a few sections so it can 'lay flat' when the petals curl. And then attach the next petal (with masking tape process repeated)
I started to add tabs, but not so great, perhaps lots and then staple it?
I still don't know how to resolve the curling ends.
Jean-Michell I modled a square, 4 sided horn for a cheap 8" (18cm) full range I have.
What should the output angle of compression driver be?
Can you explain what on earth happens with all these ripples and how im meant to glue them? For mock up sake, can i include the first curl and disregard the rest?
An externally hosted image should be here but it was not working when we last tested it.
Thanks for your invaluable help.
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Hello Studio Au,
The petal should follow the profile of the horn and roll on itself as a spiral.
Due to that rollback when the radius from the axis of the horn becomes smaller then the perimeter of the given transversal section behaves similarly, that's why the width of the petal is reduced. That's basic 3D geometry.
The wavy planar contour of the leaf is calculated in order for the group of petal to fit perfectly even with a mouth aperture angle of more than 360°.
It is probably more easy to begin to fix each petal to its neighbours from the end of the mouth than by the throat.
Best regards from Paris,
Jean-Michel Le Cléac'h
The petal should follow the profile of the horn and roll on itself as a spiral.
Due to that rollback when the radius from the axis of the horn becomes smaller then the perimeter of the given transversal section behaves similarly, that's why the width of the petal is reduced. That's basic 3D geometry.
The wavy planar contour of the leaf is calculated in order for the group of petal to fit perfectly even with a mouth aperture angle of more than 360°.
It is probably more easy to begin to fix each petal to its neighbours from the end of the mouth than by the throat.
Best regards from Paris,
Jean-Michel Le Cléac'h
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Hello Studio Au,
If you want to build a square horn then there is the problem of the throat adaptor from circle to square. Commercial adaptors are useless as they are calculated (or not) for a given expansion that is generally different of the one you need.
This spreadsheet is not suffiicent. I have another spreadsheet to calculate the adaptor.
The output angle of the compression driver is normally given by the builder or it can me measured.
Best regards from Paris, France
Jean-Michel Le Cléac'h
If you want to build a square horn then there is the problem of the throat adaptor from circle to square. Commercial adaptors are useless as they are calculated (or not) for a given expansion that is generally different of the one you need.
This spreadsheet is not suffiicent. I have another spreadsheet to calculate the adaptor.
The output angle of the compression driver is normally given by the builder or it can me measured.
Best regards from Paris, France
Jean-Michel Le Cléac'h
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I spent well over an hour reading through a few of the posts on your very fascinating thread 'Jean Michel on LeCleac'h horns' Beginning to understand it a little better. Thanks again for your dedication and passion!
The square horn, I wanted to use a full range 8" paper cone driver.
they look very similar to these on eBay, I bought mine for £1 each (bought 4 in total)
I downloaded a few of your friends calculators/spreadsheets that popped up on your thread. Would like to see how good a cardboard basshorn and a 400Hz up Le Cleac'h square profile would work out.
8" full range drivers for Lowther Acousta horn speakers on eBay (end time 16-Mar-10 17:57:33 GMT)
The square horn, I wanted to use a full range 8" paper cone driver.
they look very similar to these on eBay, I bought mine for £1 each (bought 4 in total)
I downloaded a few of your friends calculators/spreadsheets that popped up on your thread. Would like to see how good a cardboard basshorn and a 400Hz up Le Cleac'h square profile would work out.
An externally hosted image should be here but it was not working when we last tested it.
8" full range drivers for Lowther Acousta horn speakers on eBay (end time 16-Mar-10 17:57:33 GMT)
Hello Studio Au,
The easiest is to stop around x = 370mm on the blue curve on your graph (that's an inflexion point of the contour).
Best regards from Paris, France
Jean-Michel Le Cléac'h
The easiest is to stop around x = 370mm on the blue curve on your graph (that's an inflexion point of the contour).
Best regards from Paris, France
Jean-Michel Le Cléac'h
Code:
Have started a new thread regarding selling these wooden horns.
http://www.diyaudio.com/forums/vendors-bazaar/216576-1khz-wooden-horns-sale-interest.html
http://www.diyaudio.com/forums/vendors-bazaar/216576-1khz-wooden-horns-sale-interest.html
Started another thread for conicals...,
http://www.diyaudio.com/forums/planars-exotics/238497-conical-horns-600hz-up-2.html
Rough, but only a prototype...
http://www.diyaudio.com/forums/planars-exotics/238497-conical-horns-600hz-up-2.html
Rough, but only a prototype...
An externally hosted image should be here but it was not working when we last tested it.
Have been playing around with sketchup/shapeways 3D printing service.
Cost is per materials used, have been looking at making small supertweeter horns from gold plated brass.
Hard time getting my JMLC horn to work with there conversion. Have a conical one uploaded and is very reasonable.
Best horn profile for super tweeters?
Cost is per materials used, have been looking at making small supertweeter horns from gold plated brass.
Hard time getting my JMLC horn to work with there conversion. Have a conical one uploaded and is very reasonable.
Best horn profile for super tweeters?
...found these on design boom, they use veneer and sewn fabric.
I have made a wooden Goto S-150 (200-600Hz), and a paper/tape Avantgarde trio midbass+Fane 8M (120-600Hz). The paper was too soft, and the pine wood was almost too solid. Not like my 3800-8000Hz plaster/rock-like horns, but still pretty harsh to listen to. I bet for midbass, these veneer horns have really good properties.
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