Thank you very much
@jackocleebrown !
Let me start by saying you could hardly make a post too long. I don't want to be "all compliments", but I really find it a fascinating read. I have no expertise in this nor similar fields. I'm just an amateur aficionado, but I do obsess over details.
My question was aiming at speaker's demand for power when played moderately loud. In your answer you also mention this "rule of thumb" - weaker amp is enough for low level listening. I was wondering if power plays a more significant role even when not pushed to its limits. This is also why I asked about the lowest impedance dip as stated in the white paper.
There's a reputation attached to LS50 as being power-hungry. There are numerous reviews stating this. I wanted to understand it better since I do realize that if you need 1w for 85dB, you'd need 8w for 94dB. Further few watts to account for the distance to your listening position, but that's still far from what is being mentioned. I simply thought that perhaps it's because of these impedance dips. I have the first model LS50 (my next step is Meta + Sub, but I'm still waiting for some detailed read on KC62). I power them with 110wpch into 8, but with an amp measured all the way down to 2 ohms and still stable and with arguably low increase in THD. I was quite satisfied when I moved from some weaker amps (although I didn't do a proper comparison and all this could be expectations).
When you say: "
AB amps struggle to deliver power into inductive and capacitive loads and typically the most difficult frequencies are either side of the impedance dip where the magnitude is still fairly low and the phase angle deviates from zero. Such impedances make the amplifier output stage work much harder and can cause protection systems in the amp to trigger." do you, by any chance, have easily accessible numbers on how big would be this increase in power consumption for the most difficult frequencies?
Is there any real-world use of all that excess power or do we really have 40% of our power amps just idling by?