Short answer its continuous.
Speakers are given a nominal impedance rating- the actual impedance varies based on frequency.
This is why certain speakers are described as hard to drive or easy to drive.
Amp power output in relation to impedance change
How does an amplifier’s power output change in relation to impedance delta? Is it a continuous change or does it wait for certain thresholds?
for example:
Amp1 is rated at 200W@8Ohm and 400W@4Ohm. When the speaker creates let’s say a 5Ohm impedance, how much will the power output be in that case?
Amp2 is 250W@8Ohm and 300W@4Ohm, how much will the amp output be at 5Ohm?
Is the answer the same for all the classes? (A,AB and D) for example.
thank you!