We frequent a local brew pub that often has an acoustic solo or duo act. probably 4 out of 5 times we've been the act is too loud. Management has gotten good about telling them to turn the volume down. I want to hear the live music, but I also want to converse with my wife and friends. It's a balancing act for sure. One out of the 5 acts asked if the sound was ok. Since he asked, I went up and told him the volume was good but he could dial the reverb way back because the pub was a smallish room with all hard surfaces and there was more than enough reverb naturally. He did turn the effect way down and thanked me.
I always ask, " Is the sound OK, can you hear everyone in the band? are we too loud? One time when playing a restaurant with its own sound system and the owner running it he lectured me that one never does that. BTW, the sound sucked that gig.
Another thing I like about powered speaker systems is the manufacturer's engineers do all the matching up work for you.