Any one who does regular 'Pub Entertainment' and DOESNT use P A is heading straight for either Bankruptcy or a SERIOUS throat problem !

My first experience of (Excellent) P A use in a Folk Club was the seventies band Decameron . Five guys using ten microphones and a HUGE (for the time) Sound system , but at the back of the room were no louder than if the had been hammering the instruments ! Sound man kept everybody balanced , and the volume was perfect .