I have a Garrett 2500 gti with an eagle eye (two box) plus a fishers gemini-3.(two box). Close to an old metal sided barn, My garrett will not make a sound, about 12-18"from the side. while my gemini-3 will be screaming like an up-set wife.now there is no metal inside the barn,an i have moved my g-3 one way or the other,and ,about 18"either it dies out. dig it up? well, i am 82 yr. ol....YOUNG.but not that young. what do you people think????