If you're going strictly for coins & don't want to be bothered with ferrous iron chatter, you can set your vol @ 10, sens @ 10, des @ 79. The only trash signal I get is for some old pop bottle caps @ 80-82, I don't mind this, for me they're few & far between & I've found gold items at those numbers before.
If you like those settings, you can save them and they will be available (or any other settings) after you turn your machine off :-)