I have notices with my own equipment as well as making note of other musician's equipment that there seems to be a direct correlation between the amount of power (in watts) driving a PA speaker, and the quality of the sound.
Take a powered speaker for example. Common sense seems to imply that the reason you would use a 1000 watt powered speaker versus a 500 watt powered speaker - would be if you were in a larger venue covering a larger audience and needed more volume to reach a farther distance.
But I have observed that a 1000 watt speaker compared to a 500 watt speaker (even if both are the same size), will deliver a clearer, crisper, cleaner, more articulate, less mushy, and overall better sound - even if both speakers are reproducing the sound at the exact same LOW volume!
I have a basic idea of how a speaker cone reproduces sound. The signal from the source electrifies the magnet which reacts with the voice coil to produce a vibration that correlates with the source and produces the intended sound waves. But what is it about a greater degree of power in the amplifier that makes the same size speaker cone sound better with more power?
And is this phenomenon equally true whether you are using a powered speaker (with its own internal built in amplifier) or driving passive speakers with a separate power amplifier?
I do know that at higher volumes the extra power is needed to prevent clipping and distortion, but my question is about the sound with volumes well below what the speaker/amplifier combination is capable of producing.
And my question is specifically about PA speakers of they type that would be used in live sound reinforcement, not your home stereo or studio monitors.
And my presuppositions are based on my own personal observations with what I have seen. I suppose it is possible that there might be some exceptions to my opening statement, but if there are I have not found them yet.