I always run in manual sensitivity. Most the time I will max out and run at 30 even if my machine chatters when I lay it down to dig a target. I have tested this on silver coins that have not been dug yet and are in the 7-9" range at trashy parks and have noticed that if I turn my sensitivity down, even to 25-26 It will occasionally not hit that coin. I have been reading that when running in CO and in max sensitivity that its better to have the noise cancel channel at 2. Ive been running at 9 and doing well. I always ground balance my Etrac before hunting. Sometimes during the hunt if I think it needs it. Has anyone else had experience with these settings? I'm always looking to get the best performance out of any machine I use.