The "proper" way would be to take acoustic measurements and design your own using something like Jeff Bagby's Passive Crossover Designer ( Jeff Bagby's Software Page
). The "easy" way would be to add a cap on the tweets somewhere high, maybe 8-10khz, and a series padding resistor (or L-pad network) to reduce the tweeter level and let them roll. The "easy but costs more money" way would be to use an amp with wide crossover adjustment settings and a dedicated channel per speaker. You could then use the crossovers and gain settings to dial it in.