My understanding is this:
When I plug one speaker in each channel I am delivering 600Watts at 8 Ohms to each top
When I plug two speakers to each channel I am delivering 600W at 4 Ohms to each speaker
Am I correct?
I= V/R. Current equals Voltage divided by resistance. Also, P=IxE. Power equals current times voltage (
Electromotive force). Your amplifier can produce some maximum voltage, call it 64V. Into an 8Ω impedance the voltage corresponds to a current of 8A (64/8=8). The power at that voltage is 8x64, or 512W. An amp with those specs can deliver a maximum of 512W into an 8Ω load. At 4Ω the current doubles, since the voltage is the same and the current is doubled, the power has also doubled. As you lower the impedance, at some point the impedance will be so low that the amp will no longer be able to reach its specified maximum voltage, and the power will not increase proportionately. If your amp has a power spec for 4Ω, that is the amount of power it will be delivering to the pair of speakers, evenly divided between them.
Mac
edit: This is the simple view. Since the impedance of a speaker circuit is made up of resistance, inductance, and capacitance, and inductance varies with frequency, and to some extent resistance varies with temperature, there is no simple number. But for the purposes of determining what amplifier to use the manufacturer's specs are usually sufficient.