The Original, Most Iconic Loudspeaker
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 ESL-57 was also recently voted into Stuff Magazines chart of “The Top 100 Best Gadgets Ever”, being the best gadget for 1957.
Overview, Quality Control, For A Quality Sound
Pictured is an image from the late ’50s of the final hand-finished assembly process after mylar stretching and cabinet construction.
Although manufacturing is achieved today on a much larger scale, the same approach to quality has never faltered. Many processes from circuit board assembly to piano gloss finishing use hand-finished techniques, with quality control procedures each step of the way.
Matching wood-veneered panels now adorn the top of the speakers and the sides of their substantial bases, formed from high-density plywood to further damp frame resonances and smothered in layers of piano lacquer. The shielding cover on the base is embossed with the Quad logo and all typography is now in gold laquer paint; the gold-plated cable terminals, corresponding PCBs and wiring have also been enhanced.
Technology, Why is the Quad ESL 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.