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Multi-Way Conventional loudspeakers with crossovers

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Old 23rd November 2012, 07:16 PM   #661
Pano is offline Pano  United States
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The naked cells models I've seen have all been identical cells. I could not tell with the few tar-filled I've seen.
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Old 23rd November 2012, 07:56 PM   #662
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Good to know, thanks!

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Old 23rd November 2012, 07:57 PM   #663
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All cells on the 1803 are true and plumb. All terminate on the same radius curve as the front, making the center of the diaphragm the focal point, so once the sound leaves the waveguide it travels equal distance to enter all cells.
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Old 23rd November 2012, 07:59 PM   #664
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That's not right. The focal point is just behind the mounting flange, inside the waveguide, about an inch or so.
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Old 23rd November 2012, 08:48 PM   #665
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Stepping into the middle of this conversation here are a few of my thoughts, Determining the length and final mouth size should be the easiest part of this equation. Whether it is a single cell horn or a 16-cell multicell the mathematics will be the same. As long as you are following the model of the equal cells you just divide the cross-sectional area at any point by the number of cells.

Where is it written in stone that the cell need to be rectangular or squared in shape? Remember that when they made the original Altec Multi-cell horns that there was a limit to what materials they had to work with. This also limited what they did with the cross-sectional shape changes. There are many other ways that the shape change can happen and inner and outer cells can be different in cross-sectional change while the overall expansion rate of combined cell area is identical for the final cutoff frequency.
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Old 23rd November 2012, 09:16 PM   #666
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Quote:
Originally Posted by Kindhornman View Post
Where is it written in stone that the cell need to be rectangular or squared in shape?
Nowhere. I've often thought about hex cells, like a honey comb, or a combination of shapes, like the skin of a football. (soccer).
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Old 23rd November 2012, 09:21 PM   #667
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like the skin of a football. (soccer)
LOL, then it would want paying to play music - even then it would do it badly....... unless it was made in South or Latin America
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Old 23rd November 2012, 09:22 PM   #668
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Good for Brazilian music, for sure!
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Old 23rd November 2012, 10:43 PM   #669
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Quote:
Originally Posted by Cal Weldon View Post
If you look at the mouth of the horn, the middle is wider than the tabs that you have measured.
Just to make sure I'm with you, you mean in a triple row horn the edge to edge measurement on the central set of cells is wider than the same measurement taken along the top or bottom of the horn because of the curve?

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Where is it written in stone that the cell need to be rectangular or squared in shape?
I'm sure its not but there is a book called 'JRKO is a moron and 4 sides is already making his nose bleed'

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Originally Posted by GM View Post
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.

GM
An there goes my nose bleed again

Does axial length mean the distance between centres, from throat to mouth? I get the mouth area (in the 1005's case 6.25"x6.25"=39.0625") and maybe axial length (15" for the 1005) Is it throat area that I then need then to calculate the flare?

Thanks for all the effort into this guys - once I've got my brain round it I'll be glueing my fingers together in a flash!!
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Old 23rd November 2012, 11:19 PM   #670
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Quote:
Originally Posted by JRKO View Post
Just to make sure I'm with you, you mean in a triple row horn the edge to edge measurement on the central set of cells is wider than the same measurement taken along the top or bottom of the horn because of the curve?
Yes but this applies to two rows as well. Note that some connections at the mouth of the cells are 'fat', some are 'tapered' and some are 'skinny'.

So in any horn of this type, the center will be wider than the lower rows independant of the number of rows.
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