The picture shows a JBL 2446. It shows where one attaches a horn. The exit hole in the center of the driver is about 2 inches deep and 2 inches in diameter. Is that hole part of the throat chamber or does it count towards the first 2 inches of length for whatever horn you attach it to?
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I don't believe that is correct. And the reason is real simple. If you took that same horn and mounted it on a different driver that did not have that 2 inch deep hole then the results would have to be different
This is the spec sheet of JBL : https://jblpro.com/en/product_documents/2446-pdf
Been used in many designs, with different horns, but you don't have to believe me.
Good luck with your search.
Kind regards,
Willem.
Been used in many designs, with different horns, but you don't have to believe me.
Good luck with your search.
Kind regards,
Willem.
Is it tapered? (IIRC, it is?)
You can insert a pipe in a length of horn with very little change.
In this case (if a pipe) it *will* raise the throat distortion. However a coax is for near-field. You do not want to be anywhere near throat distortion of a 2" throat in its near-field. Your ears would bleed.
You can insert a pipe in a length of horn with very little change.
In this case (if a pipe) it *will* raise the throat distortion. However a coax is for near-field. You do not want to be anywhere near throat distortion of a 2" throat in its near-field. Your ears would bleed.
Common sense says that the 2 inches count towards the axially length of the horn. I looked at the JBL 2382A horn. Its axially length is 9.3 inches. Its also an exponential horn. Hornresp calculates an exponential 350Hz horns axially length as 11.22 inches. So 9.3 inches plus those 2 inches yields 11.22 inches. Therefore IMHO that 2 inches counts towards the total horns axially length.
It is not part of the throat chamber. If modelled in Hornresp, it should be specified as a throat adaptor, using parameters Ap1 and Lp.
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Thanks for chiming in. Throat adaptor, I didn’t know about that. I contacted JBL to obtain the t/s parameters of the 2446 because they are not available online anywhere. JBL will not or does not provide them upon request. So using your program to calculate the acoustical power curve is not possible.
So my real question is what impact will this 2 inch throat adaptor have on a regular 350Hz tractrix horn which is not expecting a throat adaptor. I can not cut the first 2 inches off the horn because as you know it will then not mate up smoothly to the 2 inch diameter exit from the driver
So my real question is what impact will this 2 inch throat adaptor have on a regular 350Hz tractrix horn which is not expecting a throat adaptor. I can not cut the first 2 inches off the horn because as you know it will then not mate up smoothly to the 2 inch diameter exit from the driver