I have the horn and the 10 inch on the stock crossover. That crossover seems to have a capacitor and resistor to the 10 inch. Isn't that cutting the low frequency off?
Ist that your stock crossover, are my assumptions correct?
Are the drivers connected correctly?
A phase plug for 10" is difficult and has a greater influence than you think. I would search the internet for wooden buttons that close the central hole (dust cap)
P.S
Analyzing a crossover without having it in hand and drawing a circuit diagram is very difficult. It can be notchflter, zobel network and different edge steepness in this xover.
