The reason for introducing Wrms has more to do with distortion measurements.
At some point at least in the US, requirements for producting THD+N
along with power and pre-heating requirements occured and this settled
down. The Wrms came out of that.
For a while amplifier manufacturers could measure watts any damn way they wanted to, so some used the Vpk-pk as the source for the wattage measurements, and never mind the distortion at all.
So Wrms is more of a commercial standards thing than a purely electrical one, and implies that it is a sine wave with THD+n below rated.
Have fun arguing it though.
Best,
E
For a while amplifier manufacturers could measure watts any damn way they wanted to, so some used the Vpk-pk as the source for the wattage measurements, and never mind the distortion at all.
So Wrms is more of a commercial standards thing than a purely electrical one, and implies that it is a sine wave with THD+n below rated.
Have fun arguing it though.
Best,
E