Crossover + Drivers = ??? Impedance

[nathan]

How do I determine the net impedance the amp will "see" of a 2-way crossover + drivers? I realize you might need to see my crossover design (I can email it if necessary)

Thanks a bunch,
Nate

[madrok]

The nominal impedance is usually just the nominal impedance of the woofer. Because the xover will usually just cause a spike or spikes, in a certain range, it is not relevant for rating the nominal impedance.