http://www.troelsgravesen.dk/The-Loudspeaker-2.htm
Please read this diy published equivalent of the JBL 4343-4344.
All the parts are modern drivers. It’s been designed and tested and it works.
I have looked at this design and l believe it to be an excellent modern day version of those four way JBL systems. Possibly better in some respects. There are two other versions on this website including an 18 inch woofer version.
At this late stage JBL has all but stopped supporting it’s legacy loudspeaker systems replacement parts. Some diaphragms ect are still available but the majority of recone kits are now after market from OEM parts manufacturers.
These parts are not always exactly to the JBL specifications.
Quality recone technicians/ driver re builders such as Upland Speaker Repairs modify the after market recone kits to match the JBL specifications. (Worth the wait if you want original performance)
So you have a choice.
The day is going to come when people will be building clones with alternative drivers. That’s is not that far away l will be making further references to those Troels designs as time marches on. I have been in touch with Troels and expressed positive feedback. In time l would personally prefer budding clone builders enjoy an equivalent JBL design as a reminder and a mark of respect to the JBL legacy than see it fade away. Troels has advised the JBL 4345 was his inspiration of The Loudspeaker 1 project.
http://www.troelsgravesen.dk/The-Loudspeaker.htm
Ian