Believe it or not, I've been using a Behringer 8 channel, unpowered mixer, and 8" Behringer powered speakers. I go into nursing homes and entertain, never more than 100, and I've never had the speaker volume higher than 9 o'clock.
Speakers.
http://www.zzounds.com/item--BEHB208D
Mixer.
http://www.samash.com/p/Behringer_XE...ixer_-49954001
Like I said I've been using this with heavily for over a year!