"All I have to go on is the fact that polite conversation 150 yards away outside was more than difficult because of the intrusion."

In response to this comment all I can say is that I was sat directly outside the main marquee, a lot less than 150 yards away, when several of the acts that were supposedly too loud were playing and could easily have held a polite coversation- I didn't do this as I was too busy listening to the music apart from when Paul Brady was playing as he wasn't really to my taste!