The 4590 is a 2" format driver and 2370 is 1" format horn. Jbl has a 2380 (and many others) for 2"

The 4590 could be used quite suitibly on the hi pass of 1k6 Eminence xo. You may find crossing over with something a little lower better suited also.

The 4590 is also a coax driver and either needs you to cross the mid to the high at 6300hz or there is a 4590P model which includes the a BMS passive xo at 6300hz.

There is no rising responce with this driver above 15K. The driver in a horn will gently roll out around 17K and could even benefit from having a bypass cap in the attenuating circuit.

The BMS drivers hold a line past 16K better than any other driver Ive measured.

Bill