The nominal load impedance for a mike indicates the optimum matching load which utilizes the mike’s characteristics to the fullest extent. Impedance is a combination of de resistance, inductance and capacitance, which act as resistances in ac circuits. An inductive impedance increases with frequency; a capacitative impedance decreases with frequency. Either type introduces change in phase.
"As I listen to my CD restorations, phrases like "superb quality" and "meticulous attention to detail" come to mind. Let me explain. I sent twelve LP's to CVC Productions for transfer and restoration, all of which had the pops and cracks that dusty LP's have. One LP in particular, my favorite, was so scratchy that I could no longer listen to it ..."