I was detecting the shallow water at a local fresh water beach today and I got to thinking about this. Has anyone noticed that the high-low tone is always loud, or harsh and easy to hear, but the low-high tone is quiet and you must listen very carefully to hear it. I've been digging everything in order to learn to distinguish the targets by tone. The high-low tone is nearly always ferrous trash and mostly very small targets like hair pins. I can hear these targets clearly. The low-high tone is usually a copper cent. Today I slowed my coil speed to very slow in order to hear better and the next two low-high tones turned out to be a silver dime and a silver quarter, but so hard to hear. Now, I wonder if I might have missed a lot of good targets. Am I just learning what everyone else knows, that this machine is best for extremely slow detecting and a good ear...Syd