Vintage Whine

The Original QUAD ESL

Issue 24

The first question that will probably come to mind is, “what’s with all the caps on ‘QUAD’, Leebs?”

Well, faithful reader, I’m glad you asked. I’ll get to that after a little background:

I’ve previously written a bit about how electrostatic loudspeakers (ESLs) work, way back in Copper #8.  In this piece we’ll look at the history of the best-known ESL, and try to understand why, 60 years after its introduction, many still consider it the best loudspeaker ever built.

Back in 1936, the teddibly English Peter Walker founded a company called S.P. Fidelity Sound Services. Despite my usual bull-headed research,I’ve been unable to learn what “SP” stood for. No matter: within two years, the company was known as The Acoustical Manufacturing Company, producing a portable PA system in Huntingdon, Cambridgeshire.  A tuner, pre-amp and amp for home listening (likely not yet called “hi-fi”) followed; when war came, production focused on the portable PA.

After the war, the company produced a well-regarded speaker system, the Acoustical Corner Horn. According to the company’s literature,
“The loudspeaker incorporates a freely suspended ribbon for the mid-high and high frequencies, this being loaded front and back and arranged to radiate in all directions (including the rear). A cone unit is used for the lower frequencies, the back of which is coupled to the air through a two section acoustic filter.”  The moving coil woofer was made by Goodmans, a company which will appear again in our story. The system combined direct radiation of the woofer and a rear-loaded horn. The ribbon driver utilized high-powered permanent magnet materials developed during the war (AlNiCo, perhaps?). Apparently, only a few hundred examples of this interesting design were produced; amazing photos and source material can be found on The Art of Sound website.

In 1953, Elizabeth ascended the throne, a British team climbed Everest, and Acoustical launched their Model II power amplifier (valves, of course, and still around today, somewhat modified). The Model II received the designation, “Quality Unit Amplifier, Domestic”—shortened to the acronym, QUAD (ah-HA!).  As a recalcitrant stickler for tradition when it suits my purposes, I think of the company in all caps, just as I do for FIAT and SAAB—other acronyms that slipped into common usage as proper names.

In 1955, Walker exhibited two different electrostatic speaker designs: one was open-backed and reproduced mids and highs; the other was a full-range unit in an infinite baffle enclosure. (Meanwhile, across the pond, add-on ESL tweeters were being produced by Janszen and Pickering, amongst others.) The next year, the open-back (“doublet”) unit was developed as a full-range device, and was shown at the 1956 London Audio Fair, along with another full-range ESL designed by E. J. “Ted” Jordan for Goodmans, and a tweeter from Leak. Details of the speaker’s origins and design were provided in an excellent 1957 article by Ralph West in the UK mag, Hi-Fi News (click “history” in left-hand column, then “click here” on the History page). You’ll note that the speaker was referred to as the “Quad electrostatic loudspeaker”—not all caps. Oh, well.

To review: the QUAD electrostatic (all RIGHT: Quad. Sheesh.) was, like all electrostatic loudspeakers, essentially a capacitor. A conductive plastic film acts as the diaphragm of the speaker, and is positioned between perforated metal grids. A charge is maintained on the diaphragm, and as the high voltage to the grids varies with the music signal, the diaphragm moves, producing sound.  With controlling plates on both the front and back of the diaphragm, the Quad is a push-pull design, which has lower distortion than a single-ended design. In the Quad ESL-57 (common, erroneous nomenclature; the factory only referred to it as “the Quad Electrostatic Loudspeaker”), the speaker utilizes a step-up transformer to couple output of an amplifier to the plates. Unlike many ESLs, the QUAD is not a “one-way” design, but has a tweeter panel surrounded by woofer panels on its left and right. This gives the ESL-57 limited dispersion, creating a tightly-focused “sweet-spot”, especially as only the center few inches of the tweeter produce frequencies above 7 kHz.

Quad Braun

Braun produced the LE1, an ESL 57 built under license in Germany, for many years. The angular, minimalist Dieter Rams design has its fans–I’ll take the classic Quad with its bronze metal grille.

Amazingly enough, the Quad ESL stayed in production until 1985, with about 54,000 units having been produced during its run. A new model, the ESL-63, was produced alongside the original model from 1981 until 1985. The ’63 addressed some of the issues of the original, including the narrow sweet spot and miniscule power-handling, by presenting a spherical wavefront radiating from the center of the diaphragm via  the use of a delay line, and a protection circuit which (mostly) eliminated overdriving the speaker. The fact that the ’63 started development in 1963 and didn’t reach production until 1981 should tell you how difficult it was for Walker to improve upon the original.

And yet: many preferred the ’57, and still do. The ’63’s use of a single, full-range unit, combined with the completely different radiation pattern, meant that the two were…different. Gordon Holt’s initial review of the ’63, linked above, decried its mellower character and still-inadequate power-handling.

Why does that odd little ’57  still have such a following? I can tell you that in my 45+ years of audiophilia, I’ve had exactly three demos that totally messed with my conceptions of  that which was possible with reproduced music, and all were memorable because of the speakers used. One featured the original Magneplanar Tympanis, which projected sound in a way that baffled me, and originally led me to call their sound “jukeboxy”. Another featured Hill Plasmatronics, which within their limits, simply sounded like real sound. The third game-changing demo utilized the ESL-57, which simply sounded like real music.

I don’t know how to explain the distinction between the Plas and the ’57; but I still kick myself for not buying that nice minister’s Quad system for the grand sum of $300. I expect I’ll still end up with a pair of ’57’s some day. Pleanty of people have had them forever, and never left them.

Quad kessler bookSays  our own Ken Kessler,  who literally wrote the book on the subject (Quad: The Closest Approach), “It’s hard for those outside of the UK to appreciate either their impact on the home market or to understand the genuine affection held for the brand that perseveres to this day. Devoted Quad ’57 owners are eccentrics who – like those who ‘get’ Alfa-Romeos and Lancias, or Alpa cameras – tolerate whatever quirks the Quads suffer, such as limited bass and output levels. Why? Because all the rest borders on the divine.

“Transparency, speed, detail, openness, freedom from nasties: as the speaker approaches its 60th anniversary, it remains one of the most natural-sounding transducers ever produced. In my humble opinion, the only designs I would place in the same area of the firmament devoted to music reproduction are the the BBC LS3/5A and the Apogee Scintilla. Audio notables including Dave Chesky and Tim de Paravicini swear by them, for good reason, which is as high as praise can be. Heard of their best, they are simply transcendent.”

Michael Trei wrote for Art Dudley’s Listener mag back in the day, still writes for Sound & Vision, and is known as one of the world’s foremost experts on turntable set-up. He’s also owned Quads for decades. Michael writes, “Like most loudspeakers, the Quad ESL 57 is a bundle of compromises.

“Quad’s founder Peter Walker said it best. When asked in a 1978 interview whether he was satisfied with the ESL 57 he replied, ‘Oh no, we think our loudspeaker very poor, but we think that the others are even poorer!’ Whereas most good quality conventional loudspeakers can do most things competently, the ESL 57 barely covers some areas of playback at all, while performing at true state of the art levels in most others.

“Whether or not this will work for you depends on your own priorities.

“People often say that the speakers don’t have any bass, and that they won’t play loudly at all. That’s not really true: the bass does roll off quickly below 50 Hz, but for the nine and a half octaves above that they are sublime. As for volume capability, I can easily get 100dB peaks from the listening chair, which is plenty for most sane people, although perhaps not the local frat house boys. Incidentally, when I say listening chair, I mean that literally, because the 57s are so directional at high frequencies, that they really are a one person speaker. Think of them as being a bit like a giant pair of headphones.

“Given these compromises, the ESL 57 can sound like a very small window on the recording, but it’s also the most transparent, coherent, and focused sounding window you’re ever likely to encounter. Mating them with a subwoofer can be successful if you’re careful not to overdo it, but most added super tweeters are unnecessary and  destructive to the overall cohesion. If you get a pair, charge them fully before playing them. This can take days if the panels are old and tired, but you risk damage if you try to crank them up prematurely.”

Speaking of Art Dudley, the former Editor and Publisher of Listener and current Deputy Editor of Stereophile is a longtime Quadophile (?). Art explains how he was brought into the cult. “Quad Ode: It wasn’t until age 42 that I first heard a Quad ESL—appropriately, during a visit to the UK, at a fine shop in the south called Chichester HiFi. A few years later, I made up for lost time by buying a pair of ca-1959 ESLs from an antiques dealer in New Orleans, and dove head-first into fixing them up. I can still remember the way I felt when I got my ESLs up and running: I put on “Repent Walpurgis” from Procol Harum‘s debut album, and sat transfixed as a bit of technology from the first year of the Ford Edsel changed my point of view, in this case by deepening my relationship with a record I’d been listening to for decades. Chills went down my spine, and I found myself on the verge of tears. (I might have been overtired, but still . . .)

“Since that day, other speakers have come and gone, but my Quad ESLs have never left me, and never will. They can play any kind of music, albeit sometimes by making the sounds fit the speakers rather than the other way around, and they are never less than convincing. It’s a horridly overused word, but I’ll say it anyway: Peter J. Walker was a genius.

My favorite explanation of the creamy goodness of Quads came from composer/record producer/digital pioneer David Chesky:

“Here is the real inside scoop..

“In the mid 50s Pete as I called him came to my  pad to hang out. Pete was an avid cyclist and wanted to go into the bicycle business. I was making a couple of grilled cheese sandwiches for lunch and he started staring at the cheese between the two toasted breads. And it just hit him right there. A membrane between two stators would make an amazing way to fix broken bike tires.

“I said Pete, maybe you should make a speaker like that…I lent him 50 bucks to start the thing off… and that was it, the birth of the Quad 57.

“And I have been digging them ever since……”

Thank YEW! Try the veal, tip your waiter, we’ll be here all week!

Next issue, we’ll take a look at the culture that has helped preserve and occasionally even improve Quad ESLs, for the last sixty years.

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