recently i have begun a project to enhance a speaker box that i had used as a workshop speaker for a while now, an old JBL 4530. i have verified that the enclosure was built correctly, according to the document i have found on hornplans.free.fr

from the hornresp database thread i took the values for the 4530, and started simulating drivers that i have or consider within my budget… among those i have simulated i post a screenshot of the b&c 15ndl76

i double clicked on sd and gave it the t&s it wanted

i am a little surprised that it shows almost 15dB gain from the horn, over the 100dB sensitivity b&c reports? but, surely, i would take it

after measuring the setup, my plan is to do some reduction via EQ to shape the response to what i tried to mark green in the response graph. is that a doable approach?

crossover to HF is at 800hz. currently i am using a oberton ndc72-8 on a vintage 6cell cinema horn. 

amping and dsp is wondom jab5, so it is not a maximum spl thing, but a fun bluetooth speaker 

any input is appreceated!

cheers! julius.

That's because the manufacturer's data is measured with the driver on a flat baffle, which we often call "half-space", whereas you're currently modelling in "eighth-space" - the equivalent of putting the speaker in an acoustically perfect corner such that the walls & floor of the room significantly extend the horn.

HTH,

David.

now this looks a lot different, and i am probably not going to use that driver

currently looking at celestion tf1530 (black) or fane sovereign 15-600lf (grey)

the celestion checks on qts (.281) , fs  (42) and bl (21.22) for that bin, right?

but i am still open to suggestions on the driver

best, Julius