QUAD ESL 63

9-32 — elektor september 1981 QUAD ESL 63 An opportunity to examine the circuit diagram and to listen to Peter Walker"s new loudspeaker was too good to miss . Having said that, we believe that the following article, about the rather intriguing innards of this unusual loudspeaker, will interest many of our readers. After a more general introduc- tion on electrostatic loudspeakers, to set the stage, we shall go into more detail on the ESL 63. Finally we shall discuss the way the ESL 63 behaves as a doublet and how it interfaces with listening rooms. The electrostatic loudspeaker An electrostatic loudspeaker is in several ways the counterpart of the ubiquitous moving-coil loudspeaker. Firstly in the strictly theoretical sense: the force patterned electrodes to be used. (See figure 2.) One more interesting aspect is that of the damping of the fundamental resonance. In an electrostatic drive unit this is the resonance between the diaphragm compliance (due to the earlier-mentioned res...