ESL-989

About the ESL-989

The Quad ESL-989 is a high-end electrostatic loudspeaker produced from 1999 to 2008 in England. It is the larger sibling of the ESL-988, featuring extra bass panels that extend the bass range and increase the radiating area by 50% compared to its predecessor. The speaker employs a unique system of concentric delay lines that sequentially activate electrode rings to mimic a point source, enhancing imaging and stereo staging. It is a full-range, crossoverless design with a nominal 8 ohm impedance and a sensitivity of 86dB/2.83V/m. The frequency response spans from 30Hz to 20kHz within ±6dB, with bass extension down to approximately 30Hz (-6dB). The ESL-989 is recommended to be driven by amplifiers delivering around 100 watts, with a maximum undistorted input voltage of 40-50V peak. It weighs about 25.3 kg and measures 1335 x 670 x 315 mm (H x W x D). The design is a dipole radiator, requiring careful room placement for optimal performance. The sound character is noted for its purity, coherence, and natural bass without artificial peaks, providing a spacious and three-dimensional soundstage. The cabinet is finished in black with a cloth wrap and plastic base and top cap, with some criticism of the aesthetics and plastic speaker terminals. Overall, the ESL-989 is praised for its low distortion, detailed and revealing sound, and unique electrostatic technology that allows the speaker to 'disappear' in the soundstage, creating an immersive listening experience.