I do not know how close to flat my DIY 4350’s are, my guess is that they are not flat.
This is a speaker with many faults as well as strengths, I am of the opinion that the 2” compression driver is responsible for the main fault with this monitor, this driver can easily fill a stadium by itself and at times I feel that it jumps out overpowering all other drivers in 4350, particularly at higher volumes. The stock 3107 crossover does not properly contain and control the compression driver from screaming too loud at times.
Although generally speaking JBL’s are considered better suited for pop/rock as opposed to classical, I am strictly into classical and some acoustic jazz and I prefer JBL sound to other brands for their effortless reproduction of dynamic recordings.
As for 4430, I decided not to buy for reasons cited in my previous post.
Vahe