4540 makes perfect sense. You could use this with a 1600hx xo. ITs pushing the limits of the driver si it depends on the the loudness you pland to listen to. If your only going to run a few little watts through it, milliwatts most of the time for home listening then you have no problems. If you need to crank this up for your back yard then your going to need a 4th order xo at 1600. For hom Hi-Fi your going to be fine.

Still, your going to get roll off out of the horn and this is not hot above 15k. My testing on this driver show near flat with 14db attenuation with .68uF bypass cap. This is in a 12" horn. These are my favorite BMS drivers. by far the smoothest sounding. they just have limitations and you have to cross them higher.

If you have 2370 horns then that's cool. These would also be well served in the Eminence horn Wayne sells with his kits. Its a little small horn and is much less expensive if your crossing over at 1600.

Bill