Quad ESL-63 loudspeaker Larry Greenhill part 3

The US Monitor stayed very close to the sound of the my early '63s for most vinyl recordings and CDs. The new speakers played louder than my originals, and there was an enhanced openness, particularly in the upper midrange. In addition, the amplifiers continued playing as I cranked up the volume control (my older Quads would shut down just as the amplifier's protection circuits or fuses acted). By comparison, my older ESL-63s had a "dark" tonality. In many respects, the "intact" US Monitor (with its metal screens on) sounded like the older Quad with the screens off (footnote 1). As a result, I heard more inner detailing, depth, and a better sense of spatial location in the new US Monitor. The US Monitor appeared to have more upper midrange and less bass than my old ESL-63s. This may represent some lack of rigidity in the older Quads that adds an added "whumph" in the midbass area, a byproduct of the less rigid speaker frame's vibration.

Image width excelled, with rock-stable specificity and needle-sharp focus in the far lateral field. Dispersion in the US Monitor was generous—it became possible to move around without losing the stereo image (no pinpoint "sweet spot"!). Two people (who no longer need to be Siamese Twins) sitting side-by-side could easily experience the speaker's superb imaging. The US Monitor has quickly become my hands-down favorite over all other speakers in reproducing the female voice. Grain is gone, and I felt I could "blow-up" (figuratively!) any aspect of the musical texture and find more detail. I find the image height is less restricted than that of the original ESL-63s. Although the Quad-supplied "Stand and Deliver" metal stands diminish the bass extension, the speakers become more accurate in the midbass when so elevated.

The US Monitor reproduced live recordings with a sense of immediacy and coherency that added greatly to their energy and realism. Billy Joel's Toys in the Attic was wonderful, and listenable with an immediacy I had not found before with dynamic systems. Glenn Gould's Goldberg Variations had transient speed and transparency, both on vinyl and CD, that had just not been apparent to me with other systems. The other element I must comment on: coherency. There was a sense that the soundfield emanated from a point, both bass and highs, so that I was not aware of separate transducers (which was accurate, for there is only one radiating element per loudspeaker).

Location Two
The second location was picked to allow for comparisons between the US Monitor and Sound Lab A-3s. The listening took place in Glenn Hart's (footnote 2) rectangular 15' by 24' living room, heavily carpeted and furnished with two overstuffed couches. The Sound Lab speakers were placed at one end of the room, 3' from back wall and side wall and on either side of French doors that opened onto a porch. The 6' Sound Lab A-3s sat immediately behind the Quads for listening comparisons.

Just to test the Quad's ruggedness, we used a pair of Moscode 600 amplifiers, rated at 300Wpc. The A-3s, by the way, were set up by toeing them in at 25 degrees across the door opening. A large number of vinyl records were auditioned, using an Oracle turntable and a Koetsu Black cartridge. This was followed by a highly revealing California Audio Labs Tempest II CD player and some favorite CDs. A noncontrolled format was used, listening to each selection fully, then switching to the other speaker.

First, a caveat: The listening situation in room 2 was not optimal for the Quads. We chose to leave the Sound Lab A-3s in place because of the limited time for setup and listening. The Quads' frequency balance and imaging can be affected by placement because of the bipolar sound-radiating pattern. In many ways, it may have favored the Sound Lab A-3s, which kept the "favorable" position in the room. Even so, the Quads and Sound Labs both sounded eminently natural and smooth. The Quad imaged beautifully, producing a three-dimensionality rarely exceeded by the Sound Labs.

Vocals proved very revealing. The Quads excelled on a Philips LP of soprano Fredericka von Stade, whose voice was less shrill and strained than on the A-3s. Lou Reed's Walk on the Wild Side on CD showed impressive front-to-back depth on both systems. The Tempest II CD player did pinpoint a possible frequency-balance shift in the Quads, perhaps due to their location in that room. On one CD of female vocals (Radka Toneff, Fairy Tales; Odin, BB, Oslo-Norway Records, Tottesgate), the voice took on a chestiness over the Quads that seemed to shift her entire range down. A pop vocalist, Basia, showed no changes in vocals, but the bass synthesizer took on a midbass emphasis. Using the wonderful Vanguard recording of the Weavers' 1962 Carnegie Hall Reunion ("Guantanamera"), the voice of Pete Seeger seemed more natural and less nasal on the Sound Lab A-3s; in addition, the soundstage on the A-3s was wider, and Seeger's voice was positioned further to the right.

Orchestral music showed a similar effect, with the string sound on the Quad having a very smooth, non-fatiguing quality. The A-3s, if anything, were more analytical, emphasizing inner detail. On the Pulcinella Suite, I heard what sounded like a pizzicato on violins over the Quads; the A-3s resolved this sound into a clear low-frequency drumbeat. In all fairness, the Sound Labs' ability to yield this type of low-end detail would be expected from its much larger panel system.

Clearly, the US Monitor had a very "civilized" character, and sounded smoother and less bright on some recordings than did the Sound Labs. We even noticed that vinyl record noise was less apparent on the Quads. (Perhaps this is in agreement with JGH's observation, in his original review. He found that the Quads were free of a 7kHz brightness often found in other "exotic" loudspeakers.) The comparison with the A-3s may be unjust, not just because the positioning favored the Sound Labs, but because the Sound Lab is a full-height, 6' curved panel speaker which costs 50% more than the Quads. Still, the A-3 is something of a standard at this magazine.

It is a great credit to the US Monitor that it was a serious contender with this much bigger, more expensive ESL. Both speakers proved highly detailed, natural sounding, and clean. The Quad excelled in a pinpoint three-dimensionality that gave the imaging solidity, while the A-3s created a very wide soundstage. On some recordings, we admired the A-3s' speed, snap, and open high end; it seemed more "correct." On others, it was amazing how the Quads, in a disadvantaged position, could generate a palpable, solid sonic image that we felt we could reach out and touch. The comparison should be repeated in other settings, however, if you decide to narrow your speaker selection to these two units. It is quite possible that moving the Sound Labs into a different position would have enhanced their ability to create a solid, three-dimensional image. Similarly, the openness and "correct" balance of midrange and midbass I heard from the US Monitors in my own living room could have been captured in Hart's room with different placement. Many ESLs are sensitive to room positioning.

As a current owner of the older Quad ESL-63, would I pay for a factory-sponsored upgrade to the level of the new US Monitors, if such a deal existed? Definitely! But since this is not possible (sigh!), I will have to struggle with the decision facing many Quad ESL-63 owners—should I buy a new pair of $3990 US Monitors and sell the ESL-63s? After all, I now have a suitable amplifier that won't break down (either amp or speaker) with ESL-63s. Tighter bass and a more open upper midrange make the new US Monitor a clear winner over older Quad ESL-63s. The US Monitor is much more open (perhaps because of those new metal screens), faster-sounding, with tighter bass, and slightly less blurred highs than on my ca 1983 ESL-63s.

The big news here is the Quad's increased ruggedness and reliability; it also displays slight to moderate improvements in sonics. I was impressed that the Quad (to my ears) bettered the "top-seed" A-3 system in solidity of imaging and on some recordings of high soprano voice. The speaker can't be damaged by any signal level that I threw at it (those of you who know the ML-9 will respect its punch!). It now is an acceptable speaker for pop and rock; what it loses in bass sock it more than makes up in naturalness and imaging. It is rugged, sturdy, can be moved around by one person, and is easy to place in a living room, having a good WAF (Wife Acceptance Factor, footnote 3). It can even be shipped for repairs or grille-cloth changes by UPS (the Sound Labs A-3 is platenized and shipped directly by a special trucking service). Sonically, the Quad remains one of my all-time favorite loudspeakers in terms of imaging, focus, low distortion, and low listening fatigue.

For those who are first-time buyers, the US Monitor is a godsend. If you must have an electrostatic, you will appreciate the speaker's long and honorable origins, development, and well-developed protection circuit. Its price point is set well below the most expensive Sound Labs, Apogees, Duntechs, and IRS Betas. They may excel in the deepest bass range, have more dynamics and greater soundstage width, but the US Monitor will hold its own in naturalness of sound, pinpoint three-dimensional imaging, and signal coherency over the frequency range (sounds emanating from a single source).

Footnote 1: I gave up the "barefoot" ESL approach—no metal screens—when my cat began to use the old Quads as a scratching post!—Larry Greenhill

Footnote 2: Glenn Hart, an audio writer in his own right and the Sysop of the CEFORUM on Compuserve, kindly donated time, his living room, and his Sound Lab A-3s for these tests. He also contributed valuable opinions.—Larry Greenhill

Footnote 3 Thanks again to Glenn Hart, who did not coin this term—it was Lewis Lipnick—but from whom I heard it for the first time!—Larry Greenhill

Echolane's picture

I imported my Quad ESL-63 from a London store in summer 1985 after reading a glowing review of them in Opera News. They were considered the ideal speakers for opera and classical. Unfortunately, they were unaffordable at their US price point. Luckily, I discovered they were less than half that in England, even adding in transportation and a small import duty and I have been enjoying their lovely sound ever since. I often joke that I will be buried with them, they are that wonderful for the kind of music I like, opera and classical. I snapped up a pair of US Monitors in 2023 that had just been restored to like new which should keep me happy the rest of my life.

While it’s true that they do not produce a lot of bass I’ve never missed it. But a friend loaned me a subwoofer and I’ve decided to keep it. I have it turned to barely there and am quite happy with it set to barely there. Without the need for a crossover, the sound is seamless, the midrange and highs are exquisite. I have to add that it is also fun to own them because they tend to fascinate my visitors.