I've found that on different days in different soils or sand, the same thing can ring up with different tones and numbers. I've given myself wiggle room which makes me dig more then I'd want to at least when I start out at a site. Great headphones really differentiate tones. I'm not finding much gold, but it has to be there to find it, so I'm still trying. I'd love any more advice from anyone. I go out almost everyday, cuz I'm addicted and I have the time.