Hello, this is my first post on this forum, hopefully you can help me

I recently bought a pair of used JBL 4675C (https://www.jblpro.com/ProductAttachments/4675c.pdf) and right now they are hooked up to a Pionner A-757 integrated amp. Although I am very happy with the sounds my system is producing I think I can improve it even further.

Id like to biamp and already got the JBL M553 active crossover to do so, but Id like to know what amps I should use. Of course I am going to remove the passive crossover from the speakers.

The system is used for hi-fi porpuses and loudness is not important (unless I want the neighbours to kill me ).

So what should I use and how much better will the sound get? PA-amps maybe?

Thank you very much in advance