an inch an hour
Junior Member
I wasn't sure about the threshold adjustment on the ATMax working in just all metal mode or in all modes. I've seen posts saying just all metal. I called garrett and they said threshold adjustment works in all the modes on the ATMax. They said negative threshold can be used to quiet down the machine if needed. My AT Max runs nice with full sensitivity, -3 threshold with no loss in depth when I air tested. I tested 8.5x11, 5x8, garrett coils and a nel big 15x17 coil. All showed no loss in depth. If you drop sensitivity more than 2 bars you lose depth. But -1 bar of sensitivity off and threshold setup as low as -4 threshold there is no loss in depth. I had the same results in all modes of the AT Max. Runs quiet and deep.