This thread is an index to various other threads and references on the early JBL 4-way monitors.
The 4340 was design to be biAmped.
The 4341 had a conventional crossover.
These monitors were built for roughly 2 years (1973-75) and were followed (1976) by the larger and now better known 4343 and later the 4345 monitor (18" woofers).
(Below photo credits: upper 2 pix courtesy of Anthony L100 and lower 2 pix courtesy of Riessen)
This is designed to be a longer term references to other resources here and outside on the web.
I'm trying very hard to keep the thread "on topic" so please give me the next few days before posting ANY replies or comments here.
Your PMs are most welcome.