Setting for AT MAX

Location is key, I wouldn't think a farmers field would have much unless it's really old like in England, or East Coast USA. I would dig most everything there.
Since I live on the west coast I mainly look for coin signals.
If I am in high trash I disc things out above 40
I use the At pro.

In high amounts of modern aluminum trash I put my AT Gold in Disc 1 with iron discrimination on 35 to 40. Disc 1 is similar to Zero on the AT Max. There is no notching on the AT Gold so I in thick trash I initially just go for the targets that sound really good with small circumference, left/right repeatable audio and fairly steady numbers. Any target that has those characteristics between 45 and 75 could be gold jewelry so I will dig it. If they turn out to be aluminum or falsing iron that is okay. At least I cleared out some of the more obvious targets and will have a chance of finding deeper targets which were being masked by those easier targets next time I hunt the area. Anything above 75 or so that has target characteristics like the ones I mentioned earlier is a dig it no brainer. Working through high amounts of aluminum trash takes patience and time but it can be very rewarding. Sometimes when I am overwhelmed by all of the mid tone targets, I just cherry pick the dime/quarter signals for awhile to give my ears and brain a break.

Great comments, thank you both.