Hey Chris,
What is it you intend to do with your PA? Just DJ gigs or are you doing any live sound work too? What role is the mixer playing (for you)?
I have a very strong urge to agree with Terry. I am not, and have never been, a power mixer kinda guy. They are bulky, heavy and the room the amp (controls) take is not going into other things you’d want/like in a PA mixer.
If the only reason you have the power mixer is so you can run your DJ set through it and power your JBL’s, then ditching the mixer and JBL’s and going for some active speakers is the most advisable option.
If you have more/bigger needs, let us know so we can give you some more specific pointers.
Greetinx,
C.