Thx Chris. The impedance of any decent speaker cable is minimal compared to the impedance of a speaker
The impedance associated with the crossover is included in a speakers impedance rating and the contacts should not generate significant impedance. With most speakers, significant variations in impedance do however occur with frequency. A speakers impedance rating is nominal and does not account for that fact that the impedance can vary rather wildly with frequency. It can dip very low at low frequency and this may cause problems, typically bloated bass or clipping if you push harder, if your amp is not capable of producing enough current.
The point is, ideally, the amp drives the load, which is actually the loudspeaker driver itself.
Crossover, speaker cables, contact resistance, etc are really just losses which reduce the effective damping factor applied to the drivers.