Quad ESL-57 Electrostatic Speaker Review, Specs and Price

Quad ESL-57 speaker review 1959
The Quad ESL 57 (1957)

The Quad ESL-057: World’s Best? In 1936, Peter Walker founded a company later to be known as the Acoustical Manufacturing Company. They produced portable public address systems and a hefty loudspeaker set-up the size of a bookcase. The company also manufactured an acoustical amplifier that fit into a suitcase-sized case. In 1956, just twenty years after founding the company, and in the midst of HiFi record popularity, Walker introduced the Quad ESL-57 (electrostatic loudspeaker). The design was radical, incorporating panels sandwiching an ultra-thin sheet of PET film. The sound produced was lifelike and the unit sold for about 54 pounds (around eighty US dollars). The ESL was the world´s first full-range electrostatic loudspeaker. After 500 were produced, the design was modified to accommodate the appearance of stereo records. In 1959 the ESL-57 was licensed to the German Braun Company and sold in Germany as “Braun LE1”.  In the 25 years of its production, 60,000 Quads were sold.

Quad ESL-57 Review

The Quad has a cultish following, so even now many prefer it to modern speakers. The speaker makes no noise on its own, and that is a plus; what you hear is the pure recording. Quads respond well over a wide range of frequencies, though it is at its best at mid-range and treble.
The speaker only goes down to 40 Hz, so the lowest bass octave is missing. Still, the vibrant sound from the Quad is sufficient to all but teeth-gritting ultra-low tones. The Quad ESL-57 thin diaphragm provides low sound distortion. The unit is highly directional, especially in the treble range, so they must be angled inward. The up-side to that is when they are at an angle, a “sweet spot” is formed where you can locate the soundstage easily by the tones. The main problem users see with the Quad ESL-57 is that, because of the age of the units, it is difficult to find one in good working order, and once put into use, they require maintenance.

Four Most Common Repairs of the Quad ESL-57

These speakers were built to use “good amplification of 15 watts.” Today, units of 100 watts are not uncommon. This can cause an “arced” treble panel. The most obvious signs that this has happened are:

  1. Sparks are visible in the dark at high volume
  2. You hear ticking noises or a whistling
  3. At high volume there is bad distortion keeping the volume moderate will help avoid this. Also, installing a clamp board will protect your treble panel from blowing up by regulating the voltage that goes through it.
  4. Weak high tension power is another problem that users of the Quad ESL-57 experience. The signs you have this problem are:
    • Low sensitivity ( you have to turn up the amplifier)
    • Uneven sound between left and right
    • No sound at all.
Quad ESL-57 hifi vintage advertisement speaker
Original advertisement for the Quad ESL-57

This can make you turn up the amplifier increasingly over time as the problem grows. The result will be that you blow up the treble panel at some point. As the risk increases slowly and can catch you unaware it is a good idea to have the Quad checked periodically. Periodic maintenance is also advised to combat the third problem on the list: leaking bass panels. If the Quad is experiencing this, you will notice a humming noise or the absence of bass. The high voltage operation of the bass panel can cause corrosion over time. The fourth of the repairs listed here is a leaking dust cover. If the dust cover is slack, or torn, dust in the unit can cause weird noises during playback. Obviously, when you notice this, the fix is to replace the dust cover.

Refurbishing the Quad ESL-57

Fortunately, since so many of these popular speakers were made, there is a store of original parts that can be refurbished to repair your unit. Acoustic dealers offer this service; many will deliver the parts by mail. Because they are original parts there should not be a problem with their fit. The Quad ESL 57 is arguably the most respected speaker ever made. Devotees would rather repair the units than buy new speakers which to them are inferior. There are also plenty of options available to upgrade the Quad´s vintage design.

Quad ESL-57 Price: $650-1200
(Depending on overall condition, a used pair in moderate condition should be at around $650)


  1. I acquired mine secondhand (obviously!) around 1995. They have since been serviced by One Thing Audio in 2002. Driven by a custom built 4 x EL34 valve amp they are the most natural and uncoloured speakers I have heard in over 45 years of hi-fi listening. Yes, they lack deep bass and the highest treble but remain unsurpassed in their midrange presentation. With added supertweeters and a sub there is nothing better. _

  2. Mine were made in 1976, the year in which I bought them. They cost me NZ$3,000. I have never had anything done to them. I can't understand what people meant about lack of bass. They were favoured by organists, for goodness' sake. Nothing can create more bass than an organ. I've been told mine might have lost some bass, though I can't detect it; I've even played recordings that I considered were too "bassy".

  3. I bought mine used about 20 years ago and they have provided me with many hours of great music and I've yet to hear anything, regardless of price or size, that equals these rascals. I play them at a nominal 93 db level as measured by a lab grade audio level device and the reproductin is excellent. Although I have a number of quality amplifiers to drive them with, my favorite is a pair of 70 watt gain clone chips that I packaged up some years ago and with that I retired my dyna tube amps and other things. When I want music production rathter than music reproduction I use a Mondo AB systems 480 watt per channel beast and a pair of AR303s or a pair of Bose 901 II with equalizer. Quite a range of speakers and amps but the ESL 57 are still the "Real reproducers"

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