As soon as you get into iron I would turn the reactivity back up to like 3 if the iron is dense ..but if it's not too bad the reactivity of 2 is also as quick as any machine made.. go to 12 khz for the high and low conductor's turn the audio response back to like 2 or so so you will get some nuance to the signal....I like 2 tone myself but for relics you just care about iron or not...for coins 3-4 tone might help better audibly....get a good hunt on the site with the supe fast recovery speed of the DEUS... then put the 8khz and 18Khz to you advantage,...The 18Khz is going to like coins on edge like thin silver dimes Nickles 3 center's and maybe even the elusive 1 Dollar gold piece...the 8 khz will work better coupled also with a 2 reactivity. going after the deeper larger silver coins like quarter's halves and dollars copper big penny's.. at depth in the iron...
The DEUS can be setup so much better than the other offering's...if one thing does not work you can try something else...it's a great tweaker to get what you want without screwing it up all together like some other machines can be done..
remember when you go above 3-4 on the reactivity it get's super fast but looses depth but in real dense iron depth is not going to happen anyway so separation is going to be the best bet...so use the reactivity wisely,..and to your advantage...And choose your freq's wisely when you are trying to really get surgical on a site..
Keith