Then you have the series crossovers/parallel crossovers factions. Google Bud Fried or series crossover for more.
4th order crossovers: design and time/phase issues
I have noticed some companies use 4th order crossovers...while others use 3rd, 2nd, and first...what are the advantages/disadvantages of such a crossover network...I have seen them mainly utilized on the mid-bass driver..is it possible to achieve true time/phase consistency with such a design?