I have been working with a golf course clubhouse where I am located - near Dover Air Force Base. the Venue = Jonathans Landing and they have been doing so much to try to get good blues shows going there, in a room that is acoustically Hostile.
there aren't lights, there are lots of big flat walls, hard floors, and no acustic materials in there - sort of like playing in a Racquet ball court. Only not as nice
Here you go
These were on sale at Harbor Freight - $5.99 ea so we bought about $100 worth to start.
Suddenly - you can hear bass - cymbols, etc......
I think this was on par with any equipment I could have bought to add to the PA