Exceptional sound quality,

They do need a little help from a sub and supper twitters

There is an alluring sound of the speaker because of the dipole effect; however, the goodness ends there.

There are some inherent weaknesses in electrostats. First, they are very inefficent which makes them difficult to drive. Some will argue to just add more power; but wait, inefficiency is a flaw that is not overcome. This inevitably means that the transducer material (plastic) is very lossy, which translates to a loss of detail--they actually resist current put to them and thus will fart out before reaching a reasonable concert level SPL. This is manifest in the fact that they rarely have enough treble in them, because they just aren't fast enough to reach 20k hz or beyond. Also, because of their limited excursion, they cannot produce bass and other dynamics naturally as a piston type cone speaker. Also, the sound off the back of the plastic panel diaphram is slightly later than the sound off the front, which creates phase error; something that will inevitably spear the micro details to the ear. Also, the panels are so large that they create an unatural image and sounstage. A vocalist or a guitar is not as big as the wall. On the contrary, a good box speaker can create a 3D effect in the listening space with the musicians of proper size. Also, the panel is routinely used to cover frequencies from the treble to the lower midrange, but there is no reasonable way for the panel to move at 15k cycles at the same time as 300 cycles--something must give--the end result is more detail smears and or a lack of treble. Also, plastic is known to color the tone of the signal; so if you like the sound of muted plastic instruments, this speaker is for you. This is one of the reasons why these speakers are almost always demo'd with uncomplicated acoustic type music with midrange only. If you want to hear what they are really cable of doing, play some rock or pop with them, something with not only midrange, but with complex bass and treble passages at the same time; the speakers will fall apart and quickly reveal their inabilities to fly with the box cone speaker. In the end you have a speaker that has a large cool sound, but lacks treble, bass, SPL output, refined tonality, proper imaging and detail because of its inherent design flaws. I suggest sticking with a well designed large box speaker, thus with a large woofer and all low mass, low loss material drivers such as paper cones and soft domes. There was a time when box speakers sucked and thus the electrostat was created (late 50s); however that time is long gone and manufacturers make a much better box speaker

These are by far the best speakers I have ever owned and/or listened to...and spent time on. I previously owned about 7 (seven) different specimen in a period of over three years, meanwhile sold most of them and kept two with the highest WAF (Wife Acceptance Factor). The ones with black fronts (golden being "prohibited" by better half ;-)); and a nice set of oak spiderlegs (both constructed & attached). All in all a complete overhaul has been performed during a period of about three years, ending in 2019. All cabling has been upgraded to silicon high power lines. The two EHT units replaced with completely new ones, all transformer components have been changed, conformal coating (re-)applied to the stators; all rivets have been drilled out and removed, the flimsy plastic loudspeaker posts are now golden connects. One of the prejudices is that 57s produce insufficient bass. I beg to differ - consider trying a freshly refurbished pair. In summary: be aware (!): these speakers can become highly addictive and are time consuming - most of all in combination with a Quad 303 or 405-2. In retrospect: must have spent literally 100's of hours studying, refurbishing and listening to "Walkers' Little Wonders" with a big grin on my face.

Standard plastic loudspeaker connects too flimsy; fronts easily dented; rather low WAF; units super (!) directional (complicated to find sweet spot); some spare parts are costly (stators; panels; EHT unit; transformer); increasingly hard to obtain a set in a reasonable price range; older 57's suffer from insufficient bass signal; rather bulky size hence hard to transport; potentially highly (!) addictive when functioning correctly.

I have owned a pair of these speakers since 1976 and they are still going strong. I have never had anything done to them. The front covers are rather easy to dent, unfortunately. I have a dent in both of mine. One happened when we moved house (I think) and the other when a knock at the door startled me and I dropped the vacuum cleaner hose, which struck the speaker. As far as I'm concerned my Quad equipment doesn't need replacing, though it would be nice to be able to listen to downloaded High Res music through it. I accept that this is never going to happen. I don't have $50,000 to $100,000 for new equipment.

None as far as I'm concerned. I suspect many people whose speakers no longer work have been abusing them. There was good reason why these speakers were often preferred by organists. Nothing can produce as much bass sound as an organ!

I have owned a pair of these speakers since 1976 and they are still going strong. I have never had anything done to them. The front covers are rather easy to dent, unfortunately. I have a dent in both of mine. One happened when we moved house (I think) and the other when a knock at the door startled me and I dropped the vacuum cleaner hose, which struck the speaker. As far as I'm concerned my Quad equipment doesn't need replacing, though it would be nice to be able to listen to downloaded High Res music through it. I accept that this is never going to happen. I don't have $50,000 to $100,000 for new equipment.

None as far as I'm concerned. I suspect many people whose speakers no longer work have been abusing them.

I will not repeat what so many have already said except to comment on the narrow listening. While I agree that these speakers are more sensitive to positioning and the room it is not untrue for other speakers as well.

The bottom line is the listening experience no matter where you are is excellent. I have mine in my main living area and the TV has been moved out. No matter where I am in the room ( kitchen and living area together, wider townhouse so 2.5 longer than wider. ) I can hear all the good things that have been said about these speakers.

Having said that listening alone in the sweet spot is extra special.

About 15 years ago i used to have a set of these ESL57. They were not in good shape but still quite impressive. They started to tick when you would play a little louder. I sold them and bought several other sets of speakers.
About seven years ago I found a dutch company ESL Labs (I'm dutch myself) that was specialized in refurbishing and restoring ESL57's. So i decided to find a set (not necessarily a very good set) to have them completely rebuilt at this company. New transformers, new foils, new connectors for the wires to the power amp and a overload protector. Buying the set and rebuilding them costed me about € 1600 in total and there is absolutely no other set in this budget range (new or used) that can compete with the ESL57.

The sound is so amazingly neutral. If you found a good position for your ESL's (they need space) and you found your sweet spot (it's true what everybody says: it's a small spot) they seem to disappear: you only hear the instruments in their original position, original size and with their original sound. You hear things you never heard before in the music you know so well.
The backside of this medal: so many CD's have bad recording quality and that is also revealed by listening through these ESL's.

I have a Quad 303 power amplifier (there are so many power amplifiers that cannot drive these ESL's, but this one is great). All the parts of this unit has been replaced by new parts. Especially for the big elco's I advice to do this with every amp that is older than about 10-15 years. The quality of these parts fade away and you'll hear the difference.
Further I use a Rotel pre amplifier, a Harman Kardon CD player (which is also the DAC for my Sonos Connect) and a Project 2 turntable. All this stuff is 10-15 years old or more and I really don't want to replace anything of my set. The ESL's will follow me until I die :)

My friend has a set of these Quads. Since we're both audio buffs, we'd sit and listen several times.
The pro is the sound and imaging are stellar -- once you got everything dialed in.

Unfortunately, there are several cons.
First, the "sweet spot" is very fine, almost for a single person. It took a while to arraign the speakers so they listened well. Being on the floor with a slight upward pitch, the focal point for the listener ascends. The floor footprint is rather large, so these are not for a small room and the listening area must be dedicated to just that.

My pair of 57s is middle-aged (late70s) and still sounds breathtaking. Let me amend that: the music sounds breathtaking. This iconic 50+ year-old design has simply no sound of its own, none that I can hear at least.
A sublime design - were I a speaker builder I would either give up or do my best to copy this - that closes the book firmly on nonsense like exotic cables, expensive power cords and the like. Like Sri, I use a bog-standard set of interconnects, having got rid of all my expensive designer gear. Result; bliss.

I've attempted to augment the bass with a variety of subwoofers, some being rather expensive; nothing, repeat nothing was an improvement on the original. I would say the same for supertweeters.

This is the end of the line. Unless they get eaten by giant moths (unlikely) I am devoting my time to music from here on. No other speaker has what the 57 does: a midrange to die for. The extremes of frequency are utterly unimportant by comparison. The treble, like the power of a Rolls Royce engine is "sufficient". So is the bass. Why you would want more is beyond me. For those recordings that require a lift or a tilt down I have tone controls, but I use these exceedingly rarely.

I imagine that there are a few dealers of high-end gear out there that would like these speakers to vanish off the face of the earth....it must be upsetting to realise that the last 50 years of progress has been less than progressive....

My only criticism of any importance is against myself: I try not to think of the money and time that I have spent/wasted in the last 25 years! Peter Walker got it right first time, and the fact that there is a small army of listeners who will never be parted from their 57s is a wonderful testament to that. I am one of them.

Just bought a late serial numbered version of these immortal classics. Mine are in the 45000 range, which makes them near the end of the run. I consider this the best audio purchase I have made in the last 25 years.

Simply put, there is NOTHING that come close to the sound of the original Quads. I have owned the later Quads, including the 63s and the 989s. They sound veiled and bright in comparison.

In the fairly narrow sweet spot, these have a mesmerizing sound. Strings sound meltingly pure. Voices sound spookingly real. The sound of these speakers is like listening through an open window to an instrument or voice just outside.

They have sufficient bass to satisfy almost anyone, save those who treat their stereo as a toy wanting to hear subway trains or subsonic nonsense. Even in my very large room, they play loud enough for me.

The main weakness is that they are a very narrow dispersion design. The stereo image is really only satisfying for one person.

Don't waste another nickel of your hard earned money on nonsense like cables to fix badly designed products. I am using these with zipcord. The sound is better than anything I have ever heard in the last 25 years! I can now die in peace! I paid 1600 for these. I would not sell them for 10 times that price!