Gonk speaks thusly:
"Well, if you calibrate two different systems to the same reference level (so that they both produce a 75dB test tone when the volume is set to 0, for example)... you should get the same SPL levels when the volume controls are in the same position."

Sure, that makes very good sense. The flip side, as you say, is that without equalizing the callibration like that, different systems will have comfortable volume settings that are all over the map. Doesn't really make sense to ask "what's your volume level for movies"?

I think we're saying the same thing.

You do raise a point I've wondered about though: is the db volume 'scale' really linear as suggested? If system A produces 75db test tone at "0", and system B produces 75db test tone at "-10", should we expect them to still be the same at A=-10, B=-20? The reason I wonder has to do with system calibration; and trying to decide how important it was to do the level cal's at or near typical listening volumes. If the db scale is truly linear, then it shouldn't matter at all.

And yeah, you're right, the Crown amps are enjoying an easy life of leisure these days; well deserved after years of much harder concert duty.
Can you say dynamic headroom boys and girls? ;-) The only one that get's a workout is probably my sub amp, driving what I think to be a 2ohm load (bridged amp driving 2 4ohm drivers in parallel).