This video explains XP Deus metal detector's reactivity and recovery speed. Reactivity is a key parameter of the metal detector XP Deus. It gives you a stronger sound on targets, depending on your scanning speed, but it comes with a price: Increasing reactivity may lower your depth capacity and it's directly correlated to the iron mineralization of the grounds. In this video, Gary gives us some hints on how to use reactivity to our advantage.