On the e-trac when it is on you have a constant threshold sound. now if you got any discrimination and you pass your coil over what ever you have discriminated the threshold sound nulls or goes silent. Thats ok just slow your swing down and if there is a coin or other thing you don't have discriminated in or around while nulled out the e-trac still screams out loud. now to pin point while it is nulling you have to look at your screen at your cursor and pinpoint while watching your screen until the coin id shows up and the cursor is where it need to be for your target you want to dig.