Actually what you made was completely beside the point! No one was trying to distinguish between ideal electrical efficiency and effective acoustic efficiency except for you. The simple fact is that if you know the measured sensitivity of a speaker system with 1 watt at 1 meter you can calculate directly that speaker systems efficiency in terms of % electrical energy converted to acoustical energy. That was the only point being made but thx for playing!I’d be happy to continue this back and forth until we can unequivocally distinguish between ideal electric efficiency and effective acoustic efficiency, but I believe I’ve made my point. The numbers I used as an example are from exhaustively measuring the driver, not by using the manufacturer spec sheet. The driver in question simply radiates more total acoustic power in relationship to the direct radiated power than what the log linear function predicts, pointing to it’s rudimentary roots as a simple global energy conservation equation, with simple coarse corrective terms. Don’t get me wrong, physics always wins and that expression still holds, it’s just that the energy it accounts for is not all acoustic, nor all electric, rendering it useless if you want to equate sensitivity to efficiency in effective terms, as far as I’m concerned.