You are correct. Don't confuse any comments about Gold Monster tones with what you can hear with the SDC. The Gold Monster is a VLF detector and to a degree can differentiate between iron (ferrous) scrap metal and non-ferrous metal (gold, copper, lead, aluminium, etc). The SDC is a PI detector, which has no such discrimination ability, but is much better at coping with ground mineralisation than a VLF.I thought the tone you get in scrap is the same tone you would get in gold with SDC,
I do have excellent hearing so I don't use head phones. I can hear a minuscule tone.
If I'm am wrong can someone please advise.
In my experience, excellent hearing makes headphones especially beneficial, as outside sounds (ie. distractions) are minimised and your brain can focus 100% on what the detector is telling it.