I picked up this PA. It is from around 1990. I don't believe that they are JBL made, there are no JBL logos on them. Boxes made of plywood, very nicely built. I cannot find any JBL built speaker (top boxes) with these components.
15" drivers in 4530 is 2226HPL.
I believe the top cabinets are also 2226HPL. These are ported. Midrange is 2370 horns (probably 2426 driver). 2405 tweeter. Top boxes are biamped, a passive filter is used between tweeter and horn.
I like the top boxes too much to cannibalize them. But I want to swap the 15" drivers in order to improve the midrange. And put 2420 with alu diaphragms on the horn.
Any advice on which 15" to look for is appreciated.