Here is a link to Rod Elliott's Article on Bi-amping:
ESP - The Audio Pages. How to biamp or triamp your hi-hi speaker system for greatly improved sound, and higher sound levels with less distortion.
sound-au.com
I never questioned Rod Elliot's but it was about what you said in post#20. You did not mention RE's article until you edited it, your were responding to HD, who linked Steve Munz article.
"No, it doesn't double it. It has the effect of quatrupling it! " If you were referring to bi-amp, and you seemed to be, that would not be true and I doubt Rod Elliot would have said something like that, though I will re-read that linked article of his (read it more than once in the past).
Biamp, traditionally mean using one amp for the bass drivers (or the bass an mid in some cases) and a second amp for the tweeter (or mid and tweeter in some cases). You were responding to
@lovinthehd , and I am pretty sure that's the kind of passive biamp he was talking about.
Edit: Just finished reading it, no he never said anything about quadrupling the way he interpreted it before you edited your post that originally you might be just kidding around. Your edited post and the subsequent posts now would make more sense as you provided the link. He's talking about peak power, not average, and he also noted as follow:
"It must be explained here that the 3dB effective power increase is the absolute maximum that can be obtained. In most cases it will be less - I have examined sections of music where the power gain was less than 1dB, and it can be reasonably safely assumed that the real gain will lie somewhere between 1-2dB in most cases. The real figure depends a lot on the type of music, the actual crossover frequency, and the peak to average ratio of the two separated signals. Just this topic alone is sufficient for a complete article in its own right."
Also, 2X100 W amp for bi-amp gives a total of 200 W available as the article mentioned in the beginning. As such, it should be compared with a single 200 W amp, and in that sort of apple and apple comparison, there is no gain in average power output, but in the active biamp scheme you do gain the benefits that the article highlighted. The way it was written, sorry to say this, one does have to have a strong background in EE principles, for lesser chance of misinterpreting something or taking something out of context.
So 2X100 W in active biamp scheme, depending on the music contents/waveforms, you could have an "absolute" maximum of 400 W peak effect.
A single 200 W amp without bi-amp will also get you 200 W average power output and 400 W peak power output and that would be always true, whereas in the active biamp using two 100 W amp, you only get the 400 W peak effects under certain conditions, and the article explained that quite clearly.