How to Make a New Wave Biradial Horn

So are you suggesting that the polars of the 4425MKII in post #275 (same as #276, I think) could be a work of fiction, as they look more or less like those of the 2344 ?

Besides, I also happened to find some discrepancies in the 4425 MKII tech manual (below) in which, only 25", of all dimensions, seems to be correct. It is, thus, very probable that the 4425mkII data is fictitious.
 

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So are you suggesting that the polars of the 4425MKII in post #275 (same as #276, I think) could be a work of fiction, as they look more or less like those of the 2344 ?

Besides, I also happened to find some discrepancies in the 4425 MKII tech manual (below) in which, only 25", of all dimensions, seems to be correct. It is, thus, very probable that the 4425mkII data is fictitious.
I didn't realize where you got the graphs from. Did you compare them?? What do you think?? I saw them and immediately thought of the 2234 based on the graphs in the PDF I posted.

Rob :)
 
Yes I had compared them and the one I posted looked very similar to Fig. 2a on the audioheritage paper, which is supposed to be the 2344. Hence the question above.

I didn't realize where you got the graphs from.

I don't remember where I got the better one from (image search perhaps), so I tried a reverse image search that (surprisingly) returned the following:

https://audio-heritage.jp/JBL/speaker/4425.html
https://audio-heritage.jp/JBL/speaker/4430.html

However, since it also looks like the polar in the 4425MKII manual in #275 (which is from here, try 1080p), I now think that JBL has indeed been using the same graph for many speaker models after all.
 
However, if two horns are scaled versions of each other, can't they have similar directivity, polars etc. ? Or is it truncated horns that have similar polars (with some ripple) ?
Sure I would just expect the larger to maintain directivity control to a lower frequency as long as they are the same coverage angles. May not see it that easily depends on the frequency range used to make the plots. Best resolution is here but no information beyond that

http://www.lansingheritage.org/html/jbl/specs/pro-speakers/1981-4430-35.htm
Rob :)
 
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Though the diffraction horn seems to have good coverage, I strongly believe that people these days are more interested in ones without a slot, and thus the mention of the 4425 MKII horn / waveguide. It is quite unfortunate that there's no data on this part, as opposed to the diffraction-based models.

However, from the dimensions (in mm, not inches) in the technical datasheet (post #281) and photographs of the horn, baffle and driver, my best guesses are the following:

1) The 4425 MKII baffle is 3/4" thick.
2) The "ears" seem to be project about 2 inches (47mm) out.
3) The driver (175Nd) seems to have a 2" pipe built into it, giving a minimum effective depth of 4.75" from the diaphragm.
4) The crossover frequency is 1.1kHz, that matches (more or less) the above.
5) The polars in the 4425 MKII user manual (post #275) seem to be too similar to those of 2344 and may therefore be unreliable.
 

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