The 2226J CAN go to 1600 Hz but the major question is why? You'll get less distortion in the critical midrange frequency by not asking a large bass driver to go any higher than it should. Horns have quick rolloffs below a certain point, do you have a signal generator to test these changes? Just playing music alone can be deceiving sometimes.

I would experiment with a 2nd order network on the woofer and lift the capacitor a bit with a resistor to change the filter shape a bit. Instead of grounding the capacitor put a small resistance between the capacitor and the ground. This will change the slope of the crossover a bit and might match the tweeter a little better.

Alas, trial and error are part of the equation, but also part of the fun. At least you are having fun doing it instead of having to satisfy a marketing department.