Ok I have supplies:
1x small sheet of 5mm foam board - will test if kerfing makes it useable
1x A1 sheet of mount board - might make the interior with this or maybe a 3D template
2x A1 sheets of 300gsm cartridge paper - cheap & chearful
1x A2 sheet of 350gsm watercolour paper - nice & heavy
PVA & a nice scalpel
All I need now is the exponential curve to start my trial run
1x small sheet of 5mm foam board - will test if kerfing makes it useable
1x A1 sheet of mount board - might make the interior with this or maybe a 3D template
2x A1 sheets of 300gsm cartridge paper - cheap & chearful
1x A2 sheet of 350gsm watercolour paper - nice & heavy
PVA & a nice scalpel
All I need now is the exponential curve to start my trial run
I used a lot of layers on my small horns and they were very solid. Not really sure how many you'd need here, as the metal horn cells are much thinner than single metal horns. Strength in numbers, I suppose. FWIW, I held the walls together with masking tape, then glued paper strips on top of those. Used wallpaper paste as I didn't want any PVC on my horns. Probably made no difference at all, it's just silly idea to keep them "all natural". It did work, they seemed to have no sound of their own.
You'll be building at least 16-20 cells, so why not experiment with a few to see how it goes? Materials are cheap. If you practice some and throw away the fist few, then you'll be quite good at it when you build for real.
The tricky part is getting the sides to line up once they start to curve in 3D space. My horns were 8 or 9 sided (IIRC) and shorter than 15" - thus a real struggle to join. 4 sides and longer may not be so bad. You'll soon find out!
You'll be building at least 16-20 cells, so why not experiment with a few to see how it goes? Materials are cheap. If you practice some and throw away the fist few, then you'll be quite good at it when you build for real.
The tricky part is getting the sides to line up once they start to curve in 3D space. My horns were 8 or 9 sided (IIRC) and shorter than 15" - thus a real struggle to join. 4 sides and longer may not be so bad. You'll soon find out!
1005 = 10 cells in 2 rows of 5?
6.25" is 15.875 cm so that would be 79.3...cm wide. According to this (http://www.voiceofthetheatre.com/images/multicell.3.jpg) width is 30"/5 = cells should be 6"
I typed that chart up as what A B C relates to is on the other page
--803B D26.5-----W32-----H16.25
--804B D23.5-----W32-----H16.25
--805B D17.5-----W24.5---H13
1003B D25.5------W38-----H16.125
1004B D20.5------W38.5---H16.25
1005B D17.25-----W30-----H13
1504B D21--------W38.75--H24
1505B D16.75-----W30.5---H18.5
1803B D23.5------W44------H24
1804B D23.5------W44------H24
1005B looks about the smallest - I hope I can make pretty with paper
I think I'll cover the childlike mess underneath with a fresh sheet of glam paper to finish
6.25" is 15.875 cm so that would be 79.3...cm wide. According to this (http://www.voiceofthetheatre.com/images/multicell.3.jpg) width is 30"/5 = cells should be 6"
I typed that chart up as what A B C relates to is on the other page
--803B D26.5-----W32-----H16.25
--804B D23.5-----W32-----H16.25
--805B D17.5-----W24.5---H13
1003B D25.5------W38-----H16.125
1004B D20.5------W38.5---H16.25
1005B D17.25-----W30-----H13
1504B D21--------W38.75--H24
1505B D16.75-----W30.5---H18.5
1803B D23.5------W44------H24
1804B D23.5------W44------H24
1005B looks about the smallest - I hope I can make pretty with paper
I think I'll cover the childlike mess underneath with a fresh sheet of glam paper to finish
something really big
Hello Pano. I would really like to know the curve of your 1005 horns . I wrote the other day that I wanted to clone a 1505 horn using wood veneer. This was a mistake and its the 1005 I want to clone. I was really hoping that you would offer to provide the measurements from your horns. I didn't want to ask. I think you are being very generous here. We all know how critical it will be to have the correct throat dimension. Would you consider whipping up a something similar to a auto bore snap gauge to measure this. I would be happy to make one up and send it to you if that would be better.
Hello Pano. I would really like to know the curve of your 1005 horns . I wrote the other day that I wanted to clone a 1505 horn using wood veneer. This was a mistake and its the 1005 I want to clone. I was really hoping that you would offer to provide the measurements from your horns. I didn't want to ask. I think you are being very generous here. We all know how critical it will be to have the correct throat dimension. Would you consider whipping up a something similar to a auto bore snap gauge to measure this. I would be happy to make one up and send it to you if that would be better.
Yet please Pano. I'll start with a few practice runs but it pays to have an actual product to copy. Might look at more cells for the final job as per you preference but I shouldn't get ahead of myself. Need to perfect the new art of 紙ラッパ (roughly translated as paper bugle/horn/trumpet). As far as the measurement I get from the calcs go it looks like a width every cm along the cell. Is that right?
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Correct!
6.25" is 15.875 cm so that would be 79.3...cm wide. According to this (http://www.voiceofthetheatre.com/images/multicell.3.jpg) width is 30"/5 = cells should be 6"
[/QUOTE]The front is curved. Add an extra 1/4" to each cell and you'll see the curve. From mounting tab to tab it's 28". But along the curved face between the 2 rows it's closer to 34".
If you look closely at the photo in post #650, you can see that the cells were joined by a metal strip that follows the edge. That's how they are held together across the width. I suppose you could use tape.
There is one top and bottom and another in the center. The center one may be easier to see.
There is one top and bottom and another in the center. The center one may be easier to see.
I can confirm the measurements of the 1803 against the literature. The mouth openings are the same but I didn't realize the horn sections were longer than the 1505. I thought it was just 1 more row. Learned something today.
Also, Michael your width measure doesn't take into account the extra width at the center of the horn which according to the Altec lit., is an inch more either side. Mine measures 42" at the tabs and 44" at the center
Also, Michael your width measure doesn't take into account the extra width at the center of the horn which according to the Altec lit., is an inch more either side. Mine measures 42" at the tabs and 44" at the center
The horn's axial length must be longer to have a lower cut-off, hence the flare frequency will be lower for a given mouth area.
Note these are all expo horns, so with the throat, mouth area + axial length, the flare frequency can be calculated, then input these values into an expo calculator to get the expansion over distance areas to make a template.
IIRC, the larger multi-cells don't have all cells the same shape, so if they are all made identical, then their polar response will be different, maybe to the point of having too wide/tall a 'sweet spot' unless a relatively close LP is used.
I wonder if the wood horns are correct in this respect.
GM
Note these are all expo horns, so with the throat, mouth area + axial length, the flare frequency can be calculated, then input these values into an expo calculator to get the expansion over distance areas to make a template.
IIRC, the larger multi-cells don't have all cells the same shape, so if they are all made identical, then their polar response will be different, maybe to the point of having too wide/tall a 'sweet spot' unless a relatively close LP is used.
I wonder if the wood horns are correct in this respect.
GM
If you look at the mouth of the horn, the middle is wider than the tabs that you have measured.
I will go check.
Got it. The center line is slightly wider than the top or bottom lines, yes.
Correct, but what about the horn expansion itself? IOW, are they all ~perfectly symmetrical sighting down the center-line or do they bend with at least one side being straighter?
Another thing I just thought of is that back when Steve and I were discussing these, we were talking about the old tar filled horns. I've no experience with the Aquaplas coated units, so wonder if Altec over time did a bit more cost cutting and began using just one cell shape.
GM
Another thing I just thought of is that back when Steve and I were discussing these, we were talking about the old tar filled horns. I've no experience with the Aquaplas coated units, so wonder if Altec over time did a bit more cost cutting and began using just one cell shape.
GM
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