I’m not sure which model of JBL’s you are describing as 4-way, but I think you may have 4-driver/3-way loudspeakers with frequencies allocated something like:

The 2 larger drivers handle the same 80Hz to 800Hz, one of the small drivers handles 800Hz to 3500Hz, and the other small driver handles 3500Hz to 22KHz. This is how JBL divides uses four drivers in the PC600 center speaker to handle 3 frequency ranges. JBL applies the same principle to the PT800 and perhaps others. In this way there are not two tweeters reproducing the same sounds at the same time in close proximity.

I only raised the ‘two tweeter’ issue in case you had in mind to use two identical loudspeakers with tweeters immediately next to each other as a center channel.