One Thing Audio
Quad
Reviews, ESL 57, Vintage Virtues
By Haden Boardman
The Quad Electrostatic - it's either the most fantastic loudspeaker ever produced or the most overrated piece of Fifties kitsch, a 'speaker so odd it makes you wonder just what on earth all the fuss is about.
Peter Walker's original ELS 57 electrostatic was not based on anything radically new, and in some ways can be directly linked to the work of an American, F.J. Hunt. What it was, and what it remains, is one of the world's audiophile bargains, a commercial product that broke moulds, set standards and will still be impressing people well into the 21st century.
So, now you know my view, but what about the detractors'? Well, the Quad ELS does have its flaws. I have never met the perfect speaker, and I know I never will, but ultimately you have to decide if this loudspeaker's shortcomings are something you can live with or not.
Its main drawback to me is its acoustic power output - the '57 is just not capable of playing-at earsplitting levels. Electrostatic technology is a nightmare to work with: the bigger the panel, the louder it will play, but the higher the polarizing voltages (danger!) and input it will require (causing lower sensitivity). This also makes the design harder to manufacture (larger panel gaps, greater electrical insulation), never mind 'putting up' with the things in your home.
Walker realized this problem, and I think the resultant size is more than able for the results the '57 gives. If you're still not happy with volume levels below 11 out of 10 on the dial, then the ELS is not for you. In an average room, just over 100dB is about the maximum SPL a single pair can realistically generate.
Another foible is the fact that electrostatics are also pretty directional- you have to sit on axis to enjoy the very best sound. With a stereo pair, this can get quite selfish in your average British semi! Some people don't like this and do not even try to hunt out the 'sweet spot' - they have their head too high and the 'speakers too low.
As I have said before in these pages, good stereo transducers should be directional - all dome tweeters should be binned and decent cones developed instead! The (original) electrostatics behave as a true line source. As such, the acoustic output does not drop off with distance as much as you might expect compared to a normal two-way box 'speaker. The ELS 57s do benefit from a room of reasonable size, as Quad used to recommend. However, one of the best sets I ever heard was in the tiniest room, no more than six foot by eight foot, and with a low ceiling!
In the average room, positioning can be tricky; in an ideal world, there would be just as much space behind the 'speaker as in front of it. Never put a '57 flat against a wall - it will sound appalling. Position them at least one meter from a side wall as well. Bear this in mind if you are considering buying a pair - these 'speakers are far from 'plug 'n' play'.
BASICALLY SPEAKING
The worst accusation leveled against the '57s is that they lack bass. Frankly, this is balderdash. The ELS design has the cleanest, crispest bass I have heard, even if its extension won't do justice to Bob Marley or any Drum 'n' Bass.
The real obstacle here is people's idea of what bass should sound like. The majority of commercial loudspeakers these days are brewed from Theile and Small parameters. I am not knocking the research of either Theile or Small, just the products which result from mediocre designers taking the easy route of blindly plugging numbers into equations without bothering to do any homework. This has led to an almost total stagnation of ideas in the speaker market.
The sad fact is that most of us have grown up with ported boxes that suffer exaggerated bottom-ends and badly colored bass. This artificial box-speaker 'slam' can make the Quad sound as if it lacks weight - it doesn't, it happens to be very accurate down to 45 Hz. Still some people may miss the bass bloom they've become accustomed to. Subwoofers are not my cup of tea but it is true that one of decent quality can 'lighten the load' on the '57's and allow them to play a little louder. By introducing a box in the bass, you can also gain a little coloration where most people want it.
The Quads' midrange is the best bit. Voices are amazing - no alternative can get close to the level of transparency offered by these units. The seamless integration across the whole midrange means Aled Jones or Louis Armstrong communicate clearly. The treble is similarly open, with no 'spit'. 'sizzle' or metallic 'ting'.
Some have complained in the past that the high frequency are not especially extended, but to be honest, like the coloration in the bass, it's mainly the artificial additives they are missing. Mind you, there is some merit to adding a high quality ribbon tweeter like a Decca-Kelly to the setup as it adds a little more 'air' to the soundstage.
LOADING UP
One thing you have to be very careful of is matching the '57's to an amplifier. A medium power, push-pull valve amp is about right - valves don't mind the nasty capacitve load and don't tend to get too upset by the downright vicious impedance curve (would you believe it swings from as low as 1.8ohms to over 60ohms?) Calling the Quad nominal 16ohms loads is a bit of a joke. Most well-engineered solid-state amps are equally suitable. For safety sake, though, check with the manufacturer before you risk melting your poor amp.
Power-wise, you only really need 25watts to drive these electrostats. With that 16ohm load, no harm will occur if there's little more power on tap. If your '57s have been serviced by Quad, they will have fitted a 'clamp' circuit which helps prevent overdriving and the terminal damage which results. These devices are a necessary evil when using big transistor amps, but personally I believe they spoil the sound, and if I know the 'speakers are going to be used with a moderately-powered valve amplifier, I usually remove them.
Now the worst part: servicing. Until recently, all parts were available direct from Quad. Sadly, some chemical or other going out of production meant that Quad could no longer offer spare panels for the older ELS. I'm still puzzled by how they managed to find something to build the ESL 63s and the new electrostats with, though. It would be easy to get the impression that they didn't want to keep all their old 'speakers up and running. Anyway, the good news is that the panels are now available from several sources, with Quad Gmbh in Germany having acquired the original jig.
One more word of warning; everything can and will go wrong with an ELS. With age all of the panels fade and die. EHT (Extra-High Tension) units which generate the panels' polarizing voltage, fail. Even the capacitors and resistors on the base of the audio transformer eventually give up the ghost.
Unless you can prove potential purchases have been fully serviced you can budget on at least £ 500 to sort them out. Make sure you consider this if buying a set blind or with no documentation since even a '57 on its way out can sound impressive.
As a matter of course you should replace all passive components with the best your budget can afford. Original EHT units should be swapped for some' of the newer types too - this alone can transform a tired-sounding pair. In addition, Russ Andrews recommends fitting separate EHT units to all of the panels for a worthwhile improvement.
The panels themselves can be somewhat trickier. The most delicate is the treble panel, which is swiftly barbecued by solid-state amps run too loud. A dull overall sound and crackles indicate duff treble panels. The bass units can suffer as well, losing efficiency and going pop! it is a good idea to remove the grilles and check the 'clingfilm' dust covers for tiny rips and tears.
WARNING: BEFORE YOU REMOVE A SINGLE SCREW, UNPLUG THE SPEAKER FROM BOTH THE MAINS AND YOUR AMPLIFIER AND LEAVE WELL ALONE FOR AT LEAST ONE HOUR.
The voltages within the Quad '57 can kill. Dust and moisture are the enemies of all high-voltage devices, especially ones that rely on this kind of technology to move air. Without doubt, the expanded metal grilles make a real mess of the sound, and total recluses who live on their own with no cats, dogs or rug rats would be advised to remove them completely (see warning text above For those of us without such an option, just give the
entire 'speaker a good clean out with one of those canisters of compressed air.ONE STEP BEYOND
There are so many modifications which can be applied to the Quads. However, in addition to what has been suggested already, here are a few more tweaks to consider:
- Use a decent, rigid 18in.-24in. stand. You can perhaps use even two under each' 'speaker.
- Located inside the back of the ELS panels is a covering of what looks like sackcloth. This does nought for the sound, and the tweeter panel has an even thicker chunk of felt; remove them!
- Stacking. If you are going to have a pair of crazy old 'speakers, why not be really perverse and have two pairs in a stack! Extra efficiency higher SPLs and better bass are the rewards. This requires a properly rigid frame. Most people build one which screws into the sides of the '57s in place of the wooden end cheeks.
- New frame. The original wooden carcass is not of the most solid build. Major gains can be had by building a stiffer frame.
- Ribbon tweeter. If you want to stack two pairs of '57s, this is the sort of frame you'll need. Adding a Decca-Kelly or an ATD ribbon can bring with it slightly more spaciousness. Wire in a single 6dB/octave filter - most people prefer a 2uF cap, although there's invariably room for experiment
In terms of value it is quite difficult to put a figure on the '57s. It can and will cost hundreds of pounds to get a pair back into pristine condition. At junk shops and car boots Quads have been know to go for pin money. Privately, people tend to want a bit much for tired examples, so be careful.
Later black-grille versions with IEC mains sockets command the highest prices, and it's not unrealistic to expect to pay around £1000 for a well-serviced pair. If buying 'as is' with no demo, pay as little as possible, say £50 single or £ 120 a pair.
The ELS 57 is still an awesome 'speaker. It may be nearly 45 years since 'Walker's Wonder' was first demonstrated but it remains a show-stopper to this day. If, for a fantasy moment, the ELS was still being made, you would be looking at about £2500 in new money, and I feel it would be worth every penny. (One thing Note: circa 2003, double that!)
I am not alone in preferring the older ELS to the newer ESL 63, in spite of the fact that it is much better built. I'm not taken by the audio delay circuit on the latter. Sonically, there are areas where the older model beats the newer hands down, especially in the upper-mid and treble. Maybe it's that wonderfully Fifties style that draws me to the older 'speaker. Maybe it's because it's such a bargain, and very underrated in this country.
The Quad ELS 57 is tweakable, fun and offers high-end sound at a low-end price. Call me the number-one fan!
This article first appeared in HiFi World April 1999.
