There are lots and lots of discussions about the subject to be found about this subject on the internet and from what I've read, the basic rule is that the speaker wattage should either match or be higher than the poweramp wattage (rated for the load of the speakers off-course). For PA systems, it seems to be the other way around.
My question now is if a poweramp with a higher wattage than the speakers can be used by controlling the poweramp's volume?
I have an Orange PPC212-ob cabinet which is 120W at 16 Ohm.
I'm interested in a Rocktron Velocity 300 solid-state poweramp which is rated at 170W at 16 Ohm.
Can this combination be used by controlling the volume of the Velocity 300? And if yes, what is the relation between the volume knob and the output wattage? In other words: how far can the volume knob be turned without damaging the speakers?
Btw, I know there's a lower specced Velocity 100 (which has no mono bridge and is missing definition and reactance controls) and an older Velocity 120 (which is missing the reactance control and seems hard to find) but the Velocity 300 seems superior...