I have some speakers I want to drive from a single output: a 4Ohm 300W Subwoofer, a 6.44 Ohm 60W Midrange, and 2 8Ohm 3W Tweeters. All ratings are RMS.
I know that if I were to wire all of these in parallel, the equivalent resistance would be 1.52 Ohms, but there is different power at different frequencies, so calculating the max output amp voltage isn't trivial. If my cutoff frequencies would be something like 120Hz and 2kHz and assuming my music follows a pink noise spectral power distribution, my subwoofer is taking something like 40ish times more power than my tweeters. However, this is not reflected if one treats the whole network as an equvilant resistor.
How should I approach this? I would assume that using 1.52 Ohms as the equivalent resistance and using the limiting part of the network in terms of power, the tweeters, to designate the highest voltage would be faulty. Should I instead use the pink-noise sound approximation to design my crossover with appropriate crossover frequencies and power distributions to each speaker, then just use the equivalent network resistance to calculate the max voltage the network can take? How exactly do I quantify the amount of voltage each speaker will see after all of the filtering?