You discovered the cause of why I wasn't getting the dime signal 8 inches away from a piece of trash that was 3 inches higher then the coin..THE SENSITIVITY was below 20 when I did the test, I increased it to 24 (a bit unstable) but I was able to hear the dime 3 inches away which makes me very happy...They should put in the manual that the sensitivity setting effects depth as well as detecting in trashy areas (the higher the better)..I actually increased it to 30(really unstable) and was almost able to pass the coin under the 3 inch glass test with the pulltab on top