OK, as far as I know, it is just copper coil resistance. If you wanted DC resistance, you really shouldn't use the term impedance, then, because impedance really means the AC phasor quantity whose real part is the AC resistance at the frequency of interest and whose imaginary part is the reactance at the same frequency. Sean On Fri, Mar 22, 2013 at 7:46 PM, YES NOPE9 wrote: > How is headphone impedance ( DC ) created ? That is... is it due to the = copper coil resistance or is additional resistance added via more resistive= materials or discrete resistors ? I am not asking about AC impedance. > Gus > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .