Just to make sure I state this, there will be no passive crossover design used for these speakers.
There is no way to select passive components to the tolerances needed and the time delays would require miles of wire in the delay circuits.
People can keep chasing things like Duelund caps and Jantzen foil inductors if they like, I am going the 21st century route with the dspMusik. Best sounding crossover I ever heard and easily beats passive designs with it's capabilities for things like 6 pole filter topologies and time delays.
Have fun with the comments, just play nice.