I was on kellycos site looking at headphones grey ghost , black widow and jolly Rodgers are rated for 150 to 200 hz low side high side 2000 hz to 3000hz says for metal detector usable range , What I was wondering if you can set your iron at say 75hz in your bin then you would not have to listen to the iron at all because they start at 150 to 200hz . This would let you run with open screen no disc and would not have to listen to the iron. If anybody has a set of these could you try and see if it works. sube