The relationships between resistance (ohms), current and voltage are defined by Ohm’s Law: V/I = R where V is voltage (volts); I is current (amps); R is resistance (ohms).
See link here....
https://www.physics.uoguelph.ca/tutorials/ohm/Q.ohm.intro.html
At constant V, if R increases, I will decrease.
At constant V, if R decreases, I will increase.
As a simple example (I’ll defer to Almarg or Atmasphere for their input on a better voltage value or range to use in discussing an operating amplifier)....
At 120V if R = 8 ohm, I = 15
At 120V if R = 4 ohm, I = 30
At 120 V if R = 16 ohm, I = 7.5
So you can see how greatly current requirements are affected by resistance. It’s important to remember that a speaker’s resistance might not be constant across the frequency range. Some portions of the frequency range might be associated with low resistance and consequently run up against the current limitations of the amp reproducing sound in that frequency range.
Hope this helps.