crashbandicoot i can only relay what i seen in the AT PRO, my wife and i purchased a house in Ohio the house was built in 1889 we had a fenced in back yard that was 3/4 of an acre, because of the age of the house and what little we could find out about the house in researching we decided to purchase a couple of detectors this was in late 2009 or early 2010 the two detectors we purchased was the ATP it had just come to market and a mine lab Xterra 705 with three coils the 705 was a used detector but in like new condition and came with three coils, neither of us had ever detected anything before that time, i had fiddled a little bit with a buddies old old detector but like i said neither of us had ever really detected, so we set out trying to learn how to detect,now let me tell you a Xterra 705 is not a machine for a newbie, which i was it was way above my pay grade at that time but i muddled through with it, but anyways my wife and i started hitting our back yard me with the 705 her with the AT PRO she would get a tone on the ATP I would run the 705 over the target then we would dig to find out what our treasure was, keep in mind we even went as far as doing air test with both machines in air test all showed the AT Pro to be deeper then the 705 and i am not talking a slight difference i am talking 4-6 inch difference, here is where the let down came in when we were detecting if i hit a target with the 705 and it would be reading really deep like full depth bars deep the AT PRO could not see that target at all,if the targets we went over were 6 inches or less the AT PRO would see them any deeper it would not, the Xterra 705 was hitting targets at 7-10 inches that i do not care what we would do the AT PRO would not hit, i kept telling myself this just could not be there had to be something wrong because the air test said it should not be but unfortunately it was, that is one reason i put no stock in air test to me all a air test is good for is to find out what a target IDs at, i will also say that when people are claiming to hit targets with the AT PRO at 10-12 inches i would literally have to see it with my own eyes to believe it, simply because i never could hit a target with my ATP any where close to them depths.
do not take that i am saying the AT PRO is a bad detector either, because it really is not we found many great targets in the 5-6 inch range with it just nothing deeper and keep in mind i detected that same yard all the way up to 2013 when we sold that property i still felt like it had more to give, it told me that a property is never truly hunted out