for multiple driver arrays, how to calc capacitanc

hello,

i am trying to plan a multiple tweeter driver array between 6 ohm ribbon tweeters in series-parallel circuits(keeping impedance even) and double 8 ohm woofer drivers. would like to cross at about 1khz. does anyone know the formula for calculating impedance vs capacitance? and the same for inductance. and what if you have to add a resistor? I used to know but i've gotten rusty. thanks