Tests have been done on a certain machine, if I remember correctly, about 15% of gold rings break free of the mid tone into the high pitch response, but this was an analog machine. But since the characteristics of audio/digital target response are based on raw target conductivity (with vlf machines specifically) I would say that about 95% of decent vlf machines will react the same way to the same 15% of gold rings, that is to say, assuming the particular machine has target id, that it will display into the 80% range (highly conductive) of the digital readout, and also have a nice corresponding high pitch audio response (if that particular machine has variable audio response), about 90% of the time, depending on the user, machine, conditions, etc. These particular rings are massive, so conductivity rises, so they show higher range. Which brings up another good point. Conductivity is directly proportional to size as well as alloy. That's why massive gold gives higher response, it's bigger. Don't forget depth. The deeper, the less the target "conducts". A small $1 US gold coin at 4" will probably not sound highly conductive, probably show id around pull tab let's say. But a double eagle at 4" will sound like a silver dime at 4", it's big so it's highly conductive. Like big gold rings and big bunched up gold necklaces. Small silver coins like half dimes at 5 or 6 inches easily read high conductive. Small silver coins like half dimes at 10" may just show up like iron. I have dug plenty of old shoe eyelets at 3 or 4" that sounded good and round and gold. Its madness.
