There was a misunderstanding on the part of the person you talked with who was not an electrical engineer.
Most metal detectors (including the G2 & T2) have an output resistance on the order of 100 to 300 ohms. Headphones rated at 16-32 ohms are usually loud enough for folks with normal hearing, but folks whose hearing ain't quite what it used to be will usually prefer headphones having higher impedance.
Headphones also differ in their physical construction, affecting their acoustical properties. So, there's more to it than just electrical impedance. There are aftermarket manufacturers who make headphones designed specifically for use with metal detectors. Since different people have different preferences it's not possible to say this or that one is "the best".
--Dave J.
Most metal detectors (including the G2 & T2) have an output resistance on the order of 100 to 300 ohms. Headphones rated at 16-32 ohms are usually loud enough for folks with normal hearing, but folks whose hearing ain't quite what it used to be will usually prefer headphones having higher impedance.
Headphones also differ in their physical construction, affecting their acoustical properties. So, there's more to it than just electrical impedance. There are aftermarket manufacturers who make headphones designed specifically for use with metal detectors. Since different people have different preferences it's not possible to say this or that one is "the best".
--Dave J.