Dunlavy Audio Laboratories SC-IV loudspeaker Page 2

Then there's the matter of the grille: The SC-IV manual states that the grille frame and cloth are "almost perfectly transparent," and that "the performance of the loudspeaker has been optimized with the grilles installed." Of course, I had to find out for myself.

The grilles are easy to remove and replace, so I spent a fair amount of time listening to music with the grilles on and off. My conclusion is that the effect of the grilles is admittedly minor, but, at least in my system, not negligible. With the grilles removed, the sound was just a bit more immediate, as if a veil—or, say, a grillecloth—had been removed.

Still, I'm ambivalent about unequivocally recommending removal of the SC-IV's grille. Some of my reservation is aesthetic: The speaker as supplied is an attractive piece of furniture; with the grille removed, it becomes an objet d'audiophile. Also keep in mind that I was listening off-axis; the sonic effect of the grille may be different in a setup where on-axis listening is optimal. So, like all tweaks, this is one that audiophiles should try in their own systems to find out if it represents a significant improvement.

This is a fabulous speaker! On my first day with the review pair, with the drivers not broken-in and the setup not even close to being ideal, I was hearing things on familiar records that I'd never heard before. They continued to improve with playing, reaching higher and higher levels of performance as I tweaked the setup and worked at optimizing the selection of associated components.

The most startling of the SC-IV's many strengths was the impression it gave of providing an unimpeded pathway to the musical source and to the sonic characteristics of other components in the reproduction chain. Call it transparency, revealingness, resolution, or clarity: The SC-IV had it in spades. With a good recording, the sound of instruments in an orchestra and individual voices in a chorus were presented with a timbral and spatial definition that was simply stunning.

Listening to Golden String's newly remastered release of All Star Percussion Ensemble (GS CD 005), I was struck by how individual each instrument sounded, and how clearly each instrument was defined in space. On disc 1, track 8 of Candide (Deutsche Grammophon 429 734-2), I could hear that one of the tenors in the chorus appears to have aspirations for becoming a soloist: He doesn't quite "blend." I heard all sorts of subtleties of orchestration, such as the fact that during "Mira," from Carnival (Polydor 837 195-2), the accompaniment at one point features a cello and a concertina playing the same notes.

In a previous review, I mentioned that the first CD I ever bought was 42nd Street (RCA RCD1-3891), and that I've played it countless times. I thought I knew this disc pretty well, but listening through the SC-IVs, I heard for the first time what is clearly a bad edit on "Getting Out of Town": at 0:13, the voice repeats the end of the word and is in a different space.

The differing sonic personalities of various amps and cables were easily identifiable, as were the effects of varying the tonearm VTA or demagnetizing the cartridge. One consistent effect—on both CD and LP—was that I could hear more clearly the ambience of the recording site, as well as low-level noises generated by the recording equipment itself. On Chesky's second Test CD (JD68), track 47 has, according to the liner notes, some RFI which may be apparent "on the very highest resolution playback systems." I'd listened to this many times before, and I had to really concentrate to hear it. With the SC-IVs, the RF noise was immediately apparent, spatially distinct from the music itself.

Normally, this sort of resolution has its downside, high-resolution components being described as "ruthlessly" revealing—ie, telling us things we may not have wanted to know about problems with a recording and with associated components. To some extent, this is true of the SC-IV. It's not particularly forgiving of faults in the recording process or of problems elsewhere in the system. (The original Quads are certainly "kinder" to poorly recorded material.) However, unlike many of the products that fall into the "ruthlessly revealing" category, the SC-IV doesn't seem to exaggerate existing problems—it merely reports them, together with the music. It is, in a word, accurate.

Some audiophiles have been accused of being "soundstage freaks," of placing an inordinate value on the width and depth of the soundstage and the precision of imaging, perhaps neglecting such other important sonic attributes as timbral accuracy and dynamics. If you're one of these soundstage freaks, you must listen to the SC-IVs! The "Mapping the Soundstage" test on the Stereophile Test CD 2 was reproduced with more apparent realism than I've heard before, Larry Archibald's footsteps sounding absolutely spooky as he walks to the back of the church.

In my room, I've generally found it difficult to get a clearly defined image outside of and level with the speakers (for some reason, images that are outside and deep are much better). The SC-IVs did not transcend this room limitation. However, they were no worse than any other speakers I've had in the room. (If only I had a listening room like the one in Tom Norton's new house...)

On the LEDR test (Chesky JD37), the SC-IVs went as high on the "up" test as the Unity Audio Pyramid Signatures did, the previous champ in this room, and, as with the Pyramid Signatures, the sound meandered a bit on its way up. (Again, I suspect room reflections.) For most records, the image was somewhat higher than ear-level, giving me the impression that I was looking up slightly to the stage. This is exactly the type of soundstage height I prefer—I don't care for speakers that make me feel like I'm sitting in one of the cheap seats in the balcony, looking down at the stage.

Of course, not all audiophiles are soundstage freaks. Many—including he-hates-it-when-people-refer-to-him-as-the-venerable J. Gordon Holt—place greater value on a realistic balance across the frequency range, and on the ability of a loudspeaker to accurately reproduce the timbral qualities of musical instruments and voices. Tonal balance is heavily influenced by the room and associated equipment (as, indeed, are other sonic qualities). But as far as I could tell, the SC-IV came amazingly close to the ideal of total neutrality. No part of the frequency range seemed to be emphasized; with the best recordings, instrumental and vocal timbres sounded much as they do in real life. The highs were extended without being overly etched, providing the right amount of upper-frequency "air." (My listening room has a fair amount of sound absorption; in a very live room, the SC-IV is likely to sound overbright.)

In my initial listening, I noted a bit of excessive midbass weight, but this tendency all but vanished when the speakers were spiked. The difficult midbass-to-low-bass transition was handled exceedingly well: The string bass on the "Bass Resonance" track of the second Chesky test CD had plenty of body without being heavy or sluggish. This track revealed an extremely low level of the "box" coloration that is the bane of box loudspeakers—even ones with cabinets made of exotic materials like Fountainhead (footnote 5). (Planar speakers like electrostatics or full-range ribbons, boxless by definition, don't have box resonances. But they have other problems—like panel resonances.) The relative freedom from box coloration meant that music played through the SC-IVs for the most part just seemed to be there, having little to do with the two large objects in the middle of the room.

A cursory look at the SC-IV's deep-bass spec (–6dB at 27Hz) might lead one to think that the the speaker bass would not be too impressive in this area—but then, cursory looks are often misleading. The specs are based on anechoic measurement, which doesn't take into account the effect of "room lift"; and we have to keep in mind the SC-IV's sealed-box alignment, which produces a more gradual rolloff than a ported system. In fact, the low bass was superb in both extension and quality—I'd have to rate it superior even to the previously reviewed Alán IV and the Unity Audio Pyramid Signature, neither of which are slouches in this department.

Organ-pedal notes and bass-drum fundamentals came through with full force, providing the proper underpinning to large-scale music. Testing with a sinewave generator, I got a clean 23Hz tone, with a rolloff at 20Hz. I would expect bass extension to be even greater in a larger room. Only monster-class speakers and heavy-duty subwoofers do better than this. However, in spite of the SC-IV's fairly high sensitivity (91dB/W/m) and benign impedance curve, I found that the tube amps I had available (Quicksilver Silver Monos and Luxman MQ-68c) were not very good matches—the bass became rather sluggish. The Bryston 7Bs and the Krell KSA-100S worked much better. I'd hoped to make use of the Melos Triode 200ST, a scheduled-for-review tube amp that has a reputation for sounding non-tubey, but didn't receive it in time.

Resolution, soundstaging, timbral accuracy, tonal balance, bass extension. What else is there to consider? Dynamics and "pace," that's what. Can the speaker, as Martin Colloms might say, boogie?

Now, I avoid boogieing whenever possible—not just because I'm a MAG (Middle-Aged Goat); I wasn't a boogie-man in my teens or 20s, either. I do, however, appreciate a speaker's ability to communicate the music's rhythm, and I also believe that, for the ultimate in realism, some records have to be played loud. One CD that I discovered just recently is Mickey Hart's Planet Drum (Rykodisc RCD 10206), a 1992 Grammy winner in the "World Music" category. This recording, which features a variety of drums and other percussion instruments, is an awful lot of fun, and simply begs to be played loud. I had it up to peaks that read about 105dB (C-weighting, fast response) on the Radio Shack spl meter. (The meter's inertia is such that the short-duration peaks were probably significantly higher.) The bias indicator lights on the Krell KSA-100S resembled a Christmas tree, but the sound was loud and clean, with a tremendous sense of rhythm, and with the lower-pitched drums having a punch-in-the-chest kind of power. I value my hearing too much to listen at this sort of level for too long, but it's good to know the capability is there.

Dynamic performance was at least as impressive at what, for me, is even more important: the "micro" level—the subtle variations in loudness and timing that give music its pulse. This is most readily appreciated at moderate and low playback levels, especially late at night with the lights out. Very few loudspeakers sound equally good at high and low levels (as is true of most singers—see my "Singer's Corner" Sidebar); the SC-IV belongs in that rare category. Late-night listening sessions with the SC-IVs became voyages of discovery, each record revealing more musical information than I'd thought was there.

Concluding thoughts
I started this review with a Dunlavy Audio Labs quote claiming that measurements can reliably predict a speaker's ability to reproduce music. The SC-IV is a result of this design approach: It measures exceedingly well, and sounds superb. Has John Dunlavy proven his hypothesis?

Maybe yes, maybe no. The "academic" answer is that the evidence presented is consistent with the hypothesis, but does not by itself prove it. In order for measurements to be useful, we must know what to measure, how to measure it, and, once the measurements are collected, how to interpret them.

This last phase is the most difficult, and it's here that I suspect that John Dunlavy's many years of experience in designing and building speakers is a factor, over and above the measurements themselves. Furthermore, although the DAL factory in Colorado Springs has a first-rate speaker-measurement facility, its listening room is also well set up, and Dunlavy has admitted to me that the development of his latest speakers has involved much more time spent in listening tests than in measuring per se.

For the audiophile, of course, questions about the role of measurements in speaker design are, well, academic. We're more interested in the outcome than the process, and we use our ears to evaluate that. In fact, it was the sound of the SC-IV that first brought it to my attention. When I heard it at the 1993 Summer CES, I had the feeling that I was listening to something quite special. Having had a pair in my listening room for the past three months, I know the speaker is very special. In my opinion, it's not only an outstanding speaker for anything anywhere near its price level, it's also a genuine contender for Class A status [if it had true high-level extension to 20Hz, like DAL's larger SC-VI—Ed.].

It's been said (footnote 6) that if a reviewed component is really good, the reviewer should shed tears of sorrow while he or she boxes it up to return it to the manufacturer. We might call this the Audiophile Lachrymal Response Test (ALRT), and the speakers that I've had in my listening room for review in the past two years (Acarian Alán IV, Unity Audio Signature One, and Pyramid Signature) have all passed it—at least metaphorically. I must now admit that the DAL SC-IV did not pass the ALRT. Oh, I suppose it would have, but, anticipating extensive responsiveness on the ALRT, I decided not to put myself through this aversive experience. I'm buying the review pair.

Footnote 5: One owner of electrostatics told me that he dislikes the Wilson WATT/Puppy—known for having one of the most inert cabinets in the industry—because it sounds boxy to him.

Footnote 6: By John Atkinson, during a dinner at the Old Mexico Grill in Santa Fe on December 11, 1993, if you must know.

Dunlavy Audio Labs
Company no longer in existence (2008)