Gareth, I'm sure this is typical of most outdoor concerts these day.
Yes, the speakers are on the sides of the two main stages. These were major concerts. Louder Than Life had Metallica headline two nights. Rob Zombie, Slipnot, GnR, Godsmack, Stone Temple Pilots. I think there were about 40 bands in the metal genre over the 3 days. Hometown Rising was a country version, with Tim McGraw, Frankie Ballard, Dwight Yokum, Trace Adkins, Little Big Town. Again about 40 acts, and 4 stages. Bourbon and Beyond had Foo Fighters, ZZ Top, Hall and Oates, John Fogerty, Robert Plant, Joan Jett, Flaming Lips, Blackberry Smoke, Allison Krause and more. I think attendance figures were around 100,000 per weekend.
I did enjoy reading some of the stories from local residents near the venue. While some people whined and moaned about "disturbing our peace", a bunch said it was really nice to sit outside on the back porch with a cold beer enjoying ZZ Top and Foo Fighers for free.