I've been using a Radio Shack sound meter for years. I keep it handy in my "misc box." In use, I attach it, facing me, to my USS speaker stand and to my side where I can look at it constantly. It's not only useful for controlling the volume of sound hitting your audience, but, more important, for the sound hitting my eardrums. I'm all for saving my hearing. Wish I had discovered it years ago.

Lucky