Quad ESL-57 Electrostatic Speaker

The Acoustical Manufacturing Company’s Quad ESL-57 was the world’s first production full-range electrostatic speaker. It debuted in 1957 when hi-fi speakers were big boxes and used moving-coil drivers, so the ESL-57’s flat-panel, downright minimalist design not only looked like a radical advance, its thin-film diaphragm’s low-distortion and lightning-fast transient response sounded truly revelatory to 1950s audiophile ears. The speaker’s introduction came not so many years after the transition from 78-RPM records to higher-fidelity LPs took place. The market was primed for a more transparent transducer technology, and Quad had the best-sounding speaker of the age.

Even so, the ESL-57 was designed when monophonic sound was the only home format, so the electrostatic panels had to be modified to improve their dispersion for stereo (after the first 500 speakers were manufactured). According to the 1978 Audio Amateur magazine interview with Quad’s founder Peter J. Walker, the designer wasn’t completely sold on two-channel playback and said of the ES-57’s suitability for stereo, “No, we think our loudspeaker is very poor, but we think that the others are even poorer!”

Incredibly enough, the speaker was the only electrostatic speaker in Quad’s line through 1981, when the ESL-63 speaker was introduced. It had an advanced design that offered greater bandwidth and precise imaging, but I personally know more than a few audiophiles who still cherish the original, more than half-century-old design. That’s incredible! Fifty-four thousand ESL-57s had been sold when the model was discontinued in 1985, so used ones are easy to find. The ESL-57 was hailed by critics worldwide again and again as one of the most important speakers of the 20th century. The ESL-2805 and ESL-2905 electrostatic speakers represent Quad’s current state of the art.