Celestion SL600si loudspeaker & DLP600 digital equalizer 1992 part 3

Then I hooked up the DLP600. Apart from slightly more HF energy, there didn't seem to be much obvious difference in the sound. I continued listening, putting on one CD after another. The system did seem to sing that evening. Then I switched out the EQ. "Good grief, Charlie Brown—who put Vaseline on the lens?" If subtle when switched in, the DLP600's effect on the system's overall quality represented a major loss of quality when switched out. To paraphrase Gertrude Stein, there was simply more there there with the DLP600.

I asked Digital Lad Robert Harley to come over for a second opinion. His verdict? "It's a focus control! Without the DLP, the soundstage seems diffuse, images reasonably well-defined but lacking palpability. With the DLP, it all pops into focus just as when you finally get your telescope focused on a faint galaxy." (Reviewer by day, RH transforms into an amateur astronomer by night. The rest of us here in New Mexico just wonder when he sleeps.)

The Duruflé Requiem has long been one of my favorite pieces of music, its contemplative feel so much more appropriate to the acceptance of the inevitable than, say, the bombast of the Verdi and Berlioz masses. Telarc's 1987 Atlanta recording of it, coupled with Fauré's better-known Requiem (CD-80135), is perhaps the best-performed and best-sounding, though it tended to midrange murkiness via the '600Si. Not with the DLP600 in the chain. Again, there was that essential clarifying of tonal textures. At the chorale in the first "Kyrie," trumpet and trombone are doubled in octaves. Without the DLP, their sounds tend to merge into generic brass; with it, not only can the two instruments be identified more easily, but a slight "chorus" effect becomes audible as the upper partials of the two instruments beat with each other. The voices, too, become more separate sonically, more integrated musically with the DLP600.

Incidentally, the stately moving organ-pedal line in this music quite gives the lie to the Celestion's "minimonitor" tag. With the speakers optimally set up in the room and driven by appropriate amplification, like the Mark Levinsons, the organ pedals sound deep and even.

The soundstage could also be heard to deepen, as instruments acquired a more coherent relationship with the reflections of their sounds from the walls of the recording site. On recordings that I had thought sounded rather cloudy—the Dutoit/Montréal performance of Mendelssohn's Midsummer Night's Dream (London Jubilee 430 722-2)—the soundstage opened up, with more of a sense of space apparent. This is an area where the SL600s had always fallen behind the time-coherent designs from Thiel and Vandersteen. The DLP600 significantly improved the speakers' performance in this area.

This improvement in quality did not just benefit classical recordings. I first heard bass guitarist Dean Peer's album Ucross (Redstone RR91012) in the Kinergetics room at Stereophile's 1992 LA Show, played on a pair of Avalon Eclipses reinforced in the bass with the Kinergetics SW800 stereo subwoofer system. Playing a Kubicki bass that I was astonished to learn had just four strings, Peer performs a virtuoso set of short solo pieces—with no overdubbing—that are not only musically interesting but also demonstrate every bass-playing technique known to man (and some that aren't). In particular, Peer is a master of the use of "artificial" harmonics, in which the left hand frets a note in the normal way but an additional finger lightly touches the string at what would normally be an antinode to kill the fundamental and allow a higher harmonic to sound. This may sound easy until you consider that he is doing this to every melodic note in a fast passage while also playing a bass line.

Without the DLP's EQ, the SL600Sis still managed to present a well-defined, punchy bass sound. With it, the sound became less homogenized, less "loud," while the inner play of musical voices was more apparent. The artificial reverberation used sounded less "white," less noiselike, and more spatially set back within the stage. Cymbals, too, sounded less white, less like noise and more like real acoustic objects. The SL600Si's dark high frequencies were straightened out, instrumental tonal qualities sounding considerably more natural with the DLP in the chain.

It's rare that recorded sound approaches the real thing, but at one point in my auditioning, I was almost fooled. I was playing the CBS Odyssey double-CD set of the Bruno Walter performances of the first two Mahler symphonies (MB2K 45674), which I recently bought because the Japanese CBS-Sony CD I had of Symphony 2 just doesn't come close to the LP. I was following the score—first and second symphonies are included in one Dover volume, incredible value for just $14.95—and was astonished to hear in the last movement percussion instruments that sounded incredibly real—except I couldn't see them on the page in front of me. Pressing Pause on the remote revealed a distant neighbour banging away at a piece of wood, but such was the realism of the speaker's transients when processed by the DLP that I had almost been fooled into thinking that the real was recorded. Almost.

Was the improvement offered by the DLP600 achieved without compromise? Apparently so. At times, I thought I heard a slight increase in noise modulation on flute and female chorus, but this seemed to disappear when I attempted to focus on it. I suspect the EQ is a trifle excessive in the top octave, which adds a very slight "ffff" to the sound. I also tried to listen for a slackening of rhythmic tension and reduced bass slam, both symptoms of increased data jitter, but these were conspicuous by their absence.