Low Amplifier Loads / frequency range

I was under the impression that the lowest speaker
impedances usually occur in the lowest bass, the lowest
frequency region.

But is this true ? Can the amplifier also see low loads
at other higher frequencies too ?

I am building a multi-way (active electronic crossovers
with multiple power amps) speaker system. At first I
thought I needed a high-current-capable amp only for
the bass frequencies, but now I am unsure if only one
high current amp is enough.