Quad ESL-989 electrostatic loudspeaker John Atkinson May 2003
The world of loudspeaker enthusiasts, divides readily into three camps: those who love horns, those who love panels, and everyone else. Though perhaps dwarfed by the third group, what the first two lack in numbers they make up for in passion. Art Dudley writes about this divide in his "Listening" column this month, and while I've never gone down the horn route to happiness, I have at various times in my life dabbled with panel speakers. I owned a pair of original Quads for a long time, and MartinLogan Aeriuses and CLSes as well as various Magnepans have graced my listening room for long periods. I understand what it is, therefore, about panels that causes their owners to resist the blandishments of box speakers.
So when Stereophile recently published reports from Larry Greenhill on two electrostatic speakers priced almost identically, the $7999/pair Quad ESL-989 (reviewed in November 2002) and the InnerSound Eros Mk.III (April 2003), I decided to hang on to both speakers for a while following the appearance of the reviews, to see how they sounded and measured in my own listening room.
Art Dudley describes above his experience with the Quad ESL-989s. Suffice it to say I was sad to see these unprepossessing panels leave my room to take up residence in his. There were two areas where the '989s were the best speakers I have experienced. Stereophile's founder, J. Gordon Holt, has stated that it's in the midrange where music's magic lies: if a speaker doesn't get the midrange right, it doesn't matter what else it does get right. Well, the ESL-989 got the midrange right. Got it right. Instrumental tone colors sounded more natural than I have experienced from any other speaker, as did voices. Singers just hung in the air between the speakers, palpably real.
It wasn't just the lack of coloration. The imaging, too, was superbly stable—precise enough, in fact, that the sonic signature of the microphone used to record a voice was localized in precisely the same position as the image of the voice. This was very noticeable on Ella Fitzgerald's The Songbooks (CD, Verve 823 445-2), which compiles recordings from different sessions that took place between 1956 and 1963. But oh, was Ella in the room with me!
Too areas did prove problematic. The first was practical, in that my Mark Levinson No.33H monoblocks were not happy driving the Quads—at levels above a couple of watts, the amps went into protection. As the Levinson amp has a balanced output stage, I suspect that the Quad's black input terminal is connected to ground, which is a no-no with an amp like this. I ended replacing the Levinsons with the excellent Lamm M2.1 solid-state monoblocks that Paul Bolin reviewed in April, with great success.
The second problem concerned the Quad's low-frequency balance. It took some experimentation with positioning to get the low-bass/upper-bass transition optimized, but even then there was a residual richness evident. Most of the time this was not a problem, but when the recording was overcooked in the same region—the JVC XRCD release of Oscar Peterson & Dizzy Gillespie (JVCXR-0219-2), for example, which has some awesome foot thumps—it all got a bit soggy. If your room is not a good match with the '989, then the smaller, less expensive ESL-988, which Sam Tellig wrote about in his November 2001 column, may be the better speaker for you.
I imagine that this behavior correlates with the excess of upper-bass energy that can be seen in fig.1's blue trace, which shows the Quad's in-room response averaged across an area centered on my ear position. The low bass extends down to the 31.5Hz band, and the dips at 63Hz and between 300Hz and 500Hz are not as deep as usual. In the treble, the blue trace starts to roll off above 8kHz, which is due to the speaker's restricted dispersion in its top octave. (This limited radiation pattern was shown in the original review, November 2002, p.140, figs.3 and 4.)
Fig.1 Quad ESL-989, spatially averaged, 1/3-octave, freefield response in JA's listening room (blue); on-axis response at listening position (red).
But, as shown by the minimal difference between the blue trace in fig.1 and the red trace, which is the average of the measured spectra taken on the vertical plane that passes through the listening position, the dispersion in the three octaves below 8kHz is excellent. Peculiarly, I was not aware of there being an excess of low-treble energy, as this graph would indicate. But the shape of the red trace in fig.1 does correlate very well with the quasi-anechoic response that appeared in the original review (November 2002, p.139, fig.2).—John Atkinson