A simple case of Ohms Law
RMS Voltage limit = Squart(RMS Power limit W * Nominal Impedance)
That works if loudspeakers were lightbulbs.
But since they are not-and the input voltage is very dynamic-it get a lot more complicated.
Yes that would give a "basic" answer", but not one that I would want to "stand behind" and say for sure "this is where you set it".
I have been doing a lot of "research" on limiting-how to set it up-how to easily measure where to set it and so forth.
I am writing a paper that should give some insights on "my" thoughts/procedures etc-but it is not done yet.
But let's just say that my "attitudes" have changed over the last couple of months-a good bit.
I don't want to go into it now-but the "proper procedure" (so far as my testing has lead me this far) is a good bit different than what I did/recommended in the past.
Until I am more "sure" I don't want to say anything as it is not "finalized".