Speaker Box Filter Designer is a simple and useful software for calculate the first and second order passive audio filter for 2 way and 3 way speaker box .
Version 3 includes now coil calculator based on Harold Wheeler formula for multilayer air core inductance.
Version 2 includes calculator for first, second and third order (high pass and low pass) Bessel and Buterworth active filters type.
Given the power output of the amp, it will work out the total impedance that the amp "sees", and will work out the individual power within each speaker. It has pictures of the different configurations within the spreadsheet, so you can use these as a reference for wiring the speakers .