The Original, Most Iconic Loudspeaker - QUAD ELECTROSTATICS
Designed by QUAD founder, Peter Walker in 1956, Quad demonstrated the first true full-range electrostatic loudspeaker. This remarkable product (known later as the ESL 57) used a virtually mass-less plastic film as a moving diaphragm between two charged plates. Compared with moving coil loudspeakers, the ESL 57 was free of unwanted colourations and distortions. This landmark product remained in production, virtually unchanged, for 28 years.
The ESL was the world’s first full range, ultra low distortion electrostatic loudspeaker and set standards for accuracy and fidelity in loudspeakers that remains unsurpassed to this day. A labour of love for founder Peter Walker, the ESL-57, as it came later to be known, is still revered by audiophiles all over the world.
The ESL is the complete embodiment of our company ethos “The Closest Approach To The Original Sound” and the ESL series reproduces a sound which is indistinguishable between hearing a pair of loudspeakers and having the performers right there in front of you. We are equally proud of our latest models, the ESL-2912 and ESL-2812 which have built on the original concept with improved efficiency.
The QUAD ESL-57 was also recently voted into Stuff Magazines chart of “The Top 100 Best Gadgets Ever”, being the best gadget for 1957.
The QUAD ESL 57 remained in production until 1985 with 54,000 pairs having been sold during the production run,
QUAD's second Electrostatic, the ESL 63 was introduced at the CES in 1981 (although the project was initiated in 1963), the ESL 63 was in production until 1998.
Over the years several significant upgrades to QUAD's illustrious electrostatic loudspeakers have taken place. Initially under the stewardship of the Walker family and then the Verity Group, QUAD was then aquired in 1998 by the International Audio Group (IAG) who set out to replace the ESL 63 with the all new ESL-988, a direct replacement for the out going model. At the same time the ESL-989 was introduced, having 50% more radiating area than the "63'" and being some 16" taller.
In 2005 QUAD launched the all new ESL-2805 and ESL-2905, bring the number of Electrostatic Loudspeakers in the QUAD Range to four. In terms of performance they represented a great improvement over the older 2805/2095 models: having stiffer frames and better electronics. The next challenge for QUAD's engineers was to improve the performance even more, in 2012 the new ESL-2812 and ESL-2912 models were launched replacing the 988, 989, 2805 and 2905 models.
These two models are currently the pinnacle of QUAD's development of the Electrostatic loudspeaker. These two models were the result of QUAD visiting, Alastair Robertson-Aikman the founder of SME Limited and probably the World's greatest modifier of QUAD Electrostatics Loudspeakers. What they learnt from that visit has resulted in a speaker that will play louder, go deeper in the bass while retaining all the attributes of the models that had gone before them.
The Quad ESL is more accurate than any other loudspeaker?
Why the Quad ESL is able to do so is simply because of the moving part of the Quad ESL, the electrostatic diaphragm, which is a thin layer of stretched Mylar, ten times thinner than a human hair and so light that it approaches the mass of air to which it is coupled.
As a result there is no inertia inherent in the moving parts of the Quad ESL and the diaphragm is able to respond to musical detail and transients with unparalleled precision. The Quad ESL is one of the few speakers that can reproduce a 1kHz squarewave precisely and cleanly.
To achieve this astonishing feat the Quad ESL uses a system of highly charged stator elements on either side of the diaphragm which is coupled to a power supply that produces the neccessary 5kV of EHT (Extra High Tension) charge that controls the diaphragm. How this extremely high voltage charge is produced and consistently maintained at the diaphraghm to stator interface is the key to the low distortion of the ESL.