Having had my X-70 for about a month I still have some questions that pop up after a hunt. So...today's question for the more informed. First, I always hunt in AM, 4 tones. When finding a target with a good numerical reading and sound, the following at times happens. As I pull away from the target in pinpoint mode the sound will break and sometimes hear a slight grunt. Also, upon hearing a good sound with proper tone sometimes I will lightly press the coil against the ground and wiggle the coil left and right ever so slightly. If I hear a grunt can I assume it is not a coin in both instances. I'll tell you, the more I use this machine the more I like it.