Personally, I will condition 1/2 of a glass or crystal call, on the side the callmaker has started on, with either a stone or drywall screen. I do this because I play in several of the areas around the call. I normally try to find a couple spots that sound Good to my ear, with multiple strikers. As Mike Yingling said in another post, you have about a 1" circle around the call to play and I normally play the center for that deeper gobbler yelp.