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Multi-Way Conventional loudspeakers with crossovers

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Old 15th June 2011, 04:29 PM   #5371
AllenB is offline AllenB  Australia
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I didn't mean to sound direct I believe you said that some data gets lost in ARTA when polar plotted.

If you look at the plot I posted the other day (post 5364) it looks more distinct, but it has darker contour lines. It wasn't plotted with ARTA but the data was taken with ARTA and I smoothed it 1/12 octave on the way out to prepare it for crossover work. Hoping this provides some insight.
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Old 15th June 2011, 06:13 PM   #5372
gedlee is offline gedlee  United States
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Quote:
Originally Posted by keyser View Post
Maybe it depends on the software used to generate the plots. This is what I get with ARTA. Would you post some pictures for comparison?
Quite odd that there is good resolution in the angular direction, but not in the frequency direction. In general this should be the opposite.

There are many polar maps at my website GedLee LLC. Even an interactive program that you can run.
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Old 17th June 2011, 09:21 PM   #5373
Hylle is offline Hylle  Denmark
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is there somewhere an easy to understand guid how to make the OSWG for 1" Compressiondrivers? maybe an Excel sheet that have be approved to be correct for the calculation. Also one that is easy to understand to use.
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Old 17th June 2011, 10:51 PM   #5374
Scaper is offline Scaper  United States
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is there somewhere an easy to understand guid how to make the OSWG for 1" Compressiondrivers? maybe an Excel sheet that have be approved to be correct for the calculation. Also one that is easy to understand to use.


There's a waveguide group buy going on right now from Poland and they have the OSWG-12 for $120. Fiberglass with a mirror finished gelcoat. They look really nice. I think they had 6 colors you could get, maybe 7, I can't recall right now.

Not sure if that helps at all. But it's in the group buy section.

The same company did the prototype for the SEOS-15 which was designed as a group effort by some waveguide pros much smarter than I am.

I don't know a lot about waveguides. But it was neat to see the SEOS test better than all the others. It's amazing what can be done with some group effort. The DIY community has a lot of smart people in it, that's for sure.
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Old 18th June 2011, 06:51 AM   #5375
mige0 is offline mige0  Austria
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Originally Posted by Hylle View Post
is there somewhere an easy to understand guid how to make the OSWG for 1" Compressiondrivers? maybe an Excel sheet that have be approved to be correct for the calculation. Also one that is easy to understand to use.
Go back to the roots:
Here John Kreskovsky provided the (pretty simple) geometry / math to the oblate speroid contour / curve, where Earl did fail :


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Originally Posted by gedlee View Post
Ed

This math is tricky, but it can be done with a cut and try approach.

Quote:
Originally Posted by gedlee View Post
Unfortunately this doesn't quite do it. Thats because when you simply shave off the end, when the angle is correct the throat radius is no longer correct. You have to find a new throat radius and offset such that when the angle is correct the radius is also correct. I doubt that Excel has a simple function for this. It took me a couple of pages of math to get it right.

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Originally Posted by john k... View Post
I've been following this and the "Beyond" thread.
….
Anyway, I put together an OS wave guide spread sheet that will accept throat radius, throat angle and exit angle and compute the correct profile and locate the X offset. That is, at the X offset the slope matches the input angle and the throat radius. You can down load it here: http://www.musicanddesign.com/codes/OS_wave_guide.zip


Michael

Last edited by mige0; 18th June 2011 at 06:57 AM.
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Old 18th June 2011, 07:07 AM   #5376
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Michael

Earl did not "fail". He just didn't want to give away stuff he spent a considerable amount of time on for free. Do you have a paid job? Then you failed too.
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Old 18th June 2011, 07:43 AM   #5377
mige0 is offline mige0  Austria
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If you think so ....


Michael
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Old 18th June 2011, 03:59 PM   #5378
Hylle is offline Hylle  Denmark
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Thanks, now i just have to figure out what alle the numbers means. I will also consider buying a waveguid.
Where can you see something about shape and performance of that 15" waveguid.
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Old 19th June 2011, 08:24 AM   #5379
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Originally Posted by Hylle View Post
is there somewhere an easy to understand guid how to make the OSWG for 1" Compressiondrivers? maybe an Excel sheet that have be approved to be correct for the calculation. Also one that is easy to understand to use.
Hi Hylle,

The Horn Segment Wizard in Hornresp can be used to design an oblate spheroidal waveguide. Horn dimensions can then be exported as required.

The calculations are correct :-).

Kind regards,

David
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Old 19th June 2011, 12:41 PM   #5380
doug20 is offline doug20  United States
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Thanks, now i just have to figure out what alle the numbers means. I will also consider buying a waveguid.
Where can you see something about shape and performance of that 15" waveguid.
You should consider the OS waveguides offered out of Poland. Best I have seen anywhere!
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