Surveys often leave out the better answers by not asking the right questions. My midi volumes have certain settings, my keyboard has a master volume setting, my mic and my PA or amp has another... telling you what numbers they are set on is meaningless. The question I would ask is: what are the acoustics like in the place you will be performing in ? If you have all flat, reflective surfaces (ie; glass windows w/few coverings, a smooth dance floor, high ceilings w/nothing to absorb the sound) you need very little power. The more acoustically dampened the room is, the more power you will need. Placement of the speakers can be key also: they can be tilted back on the floor for ambient sound or pointed into people's faces (many choose the latter).

I find that most live music is too loud for the occasion it is intended for, especially small gigs. It's rarely not loud enough. The trick is to get balanced sound - the right amount of bass-to-treble. Speaker quality, as opposed to quantity or size, makes the difference when going for balanced sound.

No two gigs are exactly alike. I own and use a variety of products that suit the needs of the day.