The following information is from the Quad web site:

The ESL-989 shares much of its technology with the ESL-988, but it is a larger model with two extra bass panels and a higher rated power supply. The extra panels increase the bass output, but also contribute to an enhanced performance in the mid-band, which was already widely regarded as the cleanest in the world. Although referred to as ‘bass panels’, the additional electrostatic panels are, in fact, full range (as are all the panels), but the increase in surface area allows a greater volume of air to be moved, leading to an improvement in the lower frequencies. This particular development had been anticipated for many years, but was never previously regarded as commercially and practically viable.

The ESL-989 is Quad’s finest loudspeaker. It is a true full range electrostatic loudspeaker reproducing music with an ease and naturalness that is best described as uncanny. It has a virtual absence of the familiar loudspeaker problems of coloration, distortion, phase and frequency response errors. All that remains is the music and the original ambience. To the listener these are the very ingredients needed to create a real sensation of being there. The Quad electrostatic loudspeakers are unique and continue to be in a class of their own, but now have the versatility and range to cope with a much wider repertoire.

Our consignment model is in the finish pictured above - beautiful to look at, beautiful to listen to.