1895 3/2 The potential of the low-impedance conversation circuit.
1962 J. H. Simpson & R. S. Richards ii. 26 The device thus passes most of the emitter current from a low-impedance generator to a high-impedance load.
2002 F. Broughton & B. Brewster 102 For vocals you should get a low impedance, dynamic, cardioid mic.