A Reprint from May 1999, Vol.22 No.5


Equipment Reports
Acarian Systems Alón Circe loudspeaker
Wes Phillips

Who knows not Circe,
The daughter of the Sun, whose charmed cup
Whoever tasted, lost his upright shape,
And downward fell into a groveling swine?
John Milton, Comus

Actually, maybe you know not Circe, so here's a refresher: When Odysseus landed on Aeaea, Circe placed an enchantment upon his crew, turning them into swine. Odysseus was unaffected because he was protected by an herb called Moly, a gift of Hermes, and he forced Circe to restore his crew's human forms. Odysseus then hung out with her for a year (fathering Telegonus, among other pastimes) before she dispatched him and his shipmates off to the underworld to consult Tiresias.

Description: Floorstanding three-way dynamic loudspeaker system with external passive crossover. Driver complement: 1" aluminum-dome tweeter mounted on open baffle, 5.5" pulp/plastic-cone midrange on open baffle, 10" pulp-cone woofer in sealed enclosure. Crossover frequencies: 400Hz, 3500Hz. Frequency range: 20Hz-25kHz. Sensitivity: 87dB/W/m. Impedance: 8 ohms nominal, 4 ohms minimum.

Dimensions: 52.5" H by 12.75" W by 15" D. Weight: 130 lbs each.

Serial number of units reviewed: 101/102.

Finish: Cherry with black cloth. Price: $12,000/pair. Approximate number of dealers: 60.

Manufacturer: Acarian Systems, Ltd., 181 Smithtown Blvd., Suite 104, Nesconset, NY 11767. Tel: (516) 265-9577. Fax: (516) 265-9560. Web: www.alonbyacarian.com .

Circe was the daughter of the sun god Hellos and the ocean nymph Perse. As Aetes' sister and Medea's aunt, she figures prominently in Apollonius' Argonautica, cleansing Jason and Medea for their treacherous murder of Absyrtus. Tough broad -- busy, too.

What's the audio connection? No clues here -- unless it's that this Circe, from Alón by Acarian Systems, also is capable of casting a spell. Certainly that seemed the case at HI-FI '98 last June, where the sound in the Acarian Systems/Cary room was the talk of the Show. Didn't see 'em change anyone into a swine, though--anybody who left the room a pig had probably walked in that way.

Evolution is a change from an indefinite, incoherent homogeneity, to a definite coherent heterogeneity.
The Circe is a floorstanding three-way system with an external passive crossover. Designer Carl Marchisotto explains, "We use an external crossover to reduce degradation caused by the crossover components being vibrated or modulated by magnetic fields within the speaker. Obviously, inside the speaker is not the best place to mount a sensitive electronic device." The crossover contains three separate boards -- one for each driver -- and has a hard-wired harness of Alón's own Black Orpheus cable connecting it to the Circe's three sets of binding posts. It also has three pairs of posts, which accept the speaker wire from the amplifier. Marchisotto recommends triwiring the crossover to the amplifier, thus keeping the signal paths discrete all the way back to the amp. Reacting to complaints that triwiring a speaker can lead to cable costs higher than that of the speaker itself, Marchisotto developed his own speaker cable, Black Orpheus, and offers a 10' triwired harness for $550. The bass cable uses coaxial construction, with a solid inner core and a braided outer layer made of silver-plated copper, both metals oxygen-free. The midrange and HF cables are uni-axial, using silver-clad strands and OFC in the same bundle. The cable is roughly equivalent to 13 AWG. "We take some flak over our use of a very thin insulation," Marchisotto notes; "some people equate a thick cable with a good cable. But in audio we're not dealing with high voltages, and thick dielectrics load up the capacitance, which causes losses."

Marchisotto is not exactly forthcoming concerning the crossover technology. "It's not a classical crossover. The slopes are sharper than a first-order but not as sharp as a second-order."

"So what does that make it?" I asked.
"A good crossover."
Ah.

The Circe itself is reasonably understated in a Vandersteen sort of way. The whole unit is clad in black fabric, with a cherry-wood top cap. The sealed bass enclosure houses a 10" long-throw pulp-cone woofer. On top of this cabinet is a small slanted baffle that houses a 5.5" pulp-cone midrange unit and a 1" aluminum-alloy dome tweeter. The two upper-range drivers are set into the baffle, which is open to the rear, so that they perform as dipoles. Wooden dowels support the decorative top plate above the baffle board and provide a framework for the speaker cloth.

All three drivers employ alnico magnets, which Marchisotto prefers for their "better fidelity, lower distortion, better low-level resolution, and more stable magnetic field, which translates into a more musical (more authentic, I think) harmonic structure. Alnico magnets also provide a more realistic sense of dynamics."

The midrange and woofer cones are made of pulp-based materials: Long-fiber wool is used for the woofer, while the midrange driver has a double treatment layering two different plastics over a pulp base. Marchisotto is adamant: "We prefer the low-level resolution and more natural sound of pulp-based drivers because we have found that alloy and higher-tech materials have colorations that cannot be totally compensated for in the crossover in the midrange. The HF driver is an aluminum-magnesium alloy. We don't mind using a metal dome for this frequency range because the resonance is above 25kHz, which is outside the range of hearing. Internal wiring is Black Orpheus. The six pairs of binding posts are substantial solid-copper Cardas Musicposts, which Marchisotto leaves unplated, preferring their sound that way.

If we want things to stay as they are, things will have to change.
Maybe it was Circe's transformative powers that inspired the speaker's name. As I shuffled amplifiers and wires, the speakers went through some real personality changes. Marchisotto is insistent that the Circes be used only with components of the very highest quality, which, for him, include single-ended triode amplifiers such as the Cary CAD-805C monoblock. So I had Dennis Had send me a pair and began the proceedings with a Marchisotto-approved system consisting of an Audio Research CD2/DAC3 or Linn Sondek LP12/Lingo/Cirkus/Ekos/Arkiv/Linto front-end driving the Conrad-Johnson ART and Cary 805C combo.

First, we spent a great deal of time finding the right interconnects. Two that worked well were the Siltech SQ-80 G3 and AudioQuest Lapis. There are probably other cables I could have tried, but cable comparisons aren't high on my list of fun activities. I can hear the tonal purity that people respond to in single-ended amplifiers, but I suspect I'm just not an SE kinda guy at heart. The highs were sweet and lovely, but I found the Circe's overall sound flaccid and very old fashioned with the 805Cs. Nor was I getting the low-level resolution I thought a $12,000/pair loudspeaker ought to exhibit. It was as if I'd stepped back in time 25 years. By dialing in more negative feedback, I did get the amp to control the bottom end better, but the top end's purity suffered as the bass tightened up. For my tastes, and in my room, this was not a magic combination.

"The bass was impressive -- the bottom end is
taut, tuneful, and quite deep."

The far more powerful Audio Research VT200 was a different kettle of fish entirely. Highs were now extended and detailed -- less sweet, perhaps, but light-years removed from harsh or forward. The midrange was extraordinary; I could hear waaay into recordings now. And the bass was impressive as the dickens. I got similar results when I tried a Mark Levinson No.332 and a pair of Accuphase M2000s, but the overall harmonic signature was considerably less rich. I don't go so far as to insist on SE triodes, but tube amplification sure did seem to bring out the best in the Circe. One other setup consideration: Since the Circes are dipoles above 400Hz, you must position them carefully. They need breathing room to their sides and, in my room at least, quite a bit of space behind them. In a rectangular room, I'd start with them placed on the long wall first. In some rooms they might benefit from some slight toe-in, but not in mine -- I pointed 'em straight forward, about 6' apart and 4' from the front wall, with my listening chair 10' in front of them.

The one remains, the many change and pass.
If'n you ask me, the Alón Circe needs a fairly hefty amplifier. But properly driven, the Circe delivers the bass goods. The bottom end is taut, tuneful, and quite deep. I really enjoyed listening to recordings with extreme low-frequency information, such as Robert Rich's Seven Veils (Hearts of Space 11086-2), an electroacoustic fantasy on Eastern trance-inducing music.

I realize that a lot of audiophiles have nothing but contempt for this whole genre of music, claiming that since it is an artificial construct, without reference to a real-world performance, it is thus not as worthwhile as more "authentic" music types, which at least are performed in concert halls, stadiums, drawing rooms, or coffee houses. But this is a false distinction, to my mind, once we're talking of recordings -- unless we're referring to that very small handful recorded in a purist two-mikes-in-a-hall fashion. Almost any studio recording these days has an audio environment constructed by its engineer, who chooses how much acoustic space informs the instruments, and where the instruments are represented in the soundstage -- to the point where different instruments in the mix may be informed by different acoustics, even when recorded in the same space at the same time. The best "soundscape" manipulators, such as Rich, create sonic worlds as rich and fascinating as any captured by the purists -- some might even argue more so.

Seven Veils sounded fantastic on the Circes. The bass was incredibly deep and articulate, brimming over with warmth. The differences in the manipulated acoustics used in each piece were easily distinguished. The admittedly artificial soundstage didn't sound that way -- Rich is a genius at constructing believable soundscapes, and the ones on Seven Veils are convincing.

The bass on Jimmie Vaughan's Out There CD (Epic EK 67653) was powerfully boogielicious as well. Vaughan doesn't use a bass player, most of the bottom on this disc coming from his own tasty guitar work and Bill Willis' Hammond B-3. Yet on this disc as well, I was aware of a bottom-end warmth quite different from that of the similarly priced B&W Nautilus 801 that I reviewed in January.

Is this a characteristic of the Circe, or the difference between a well-designed ported enclosure and a sealed-box design? I can't say for sure, but the Circe's bass signature reminded me of the AR-3 and the larger Advent loudspeakers -- classic designs from my youth. Not bad company to keep, but representative of a sound that won't appeal to everyone. I have to admit I find it quite attractive, but I'm not sure I'd want to experience it every day.

The midrange and top end certainly do not partake of any classic coloration, however. Time after time, I was drawn into the music through the exceptional purity of the Circe's mids and highs. Voices and winds sounded remarkably present. Having played (badly) in my day a fair amount of recorder and end-blown flute, I'm intimately familiar with the sounds of these instruments, and most recordings (and hi-fis) tend to blunt the sharp harmonics they produce. In a recorder ensemble, no matter how mellow the primary tones, the overtone structures are filled with clangor, a property the Alóns reproduced with astonishing verisimilitude on the Flanders Recorder Quartet's Armonia di Flauti (CD, Opus 111 OPS 30-201). The speakers reproduced not just the sound of four recorders, but also that of the space in which they were being played, with an immediacy that bordered on the frightening.

Here's a funny thing: My old Verve and Milestone LPs sounded fantastic on these speakers. Of course, many of them are just great-sounding records, but there seemed to be an affinity between the Alóns and my vintage jazz discs that just worked magic. Some of this might be attributed to that hint of bass warmth -- which certainly did suit the bass lines of Leroy Vinnegar, Ron Carter, Reggie Workman, et al -- but that wasn't all of it. There was a rightness and balance to these '60s-era discs that was impossible to deny. I can't explain it, but I certainly did dig it.

One other minor quibble: The Circe seems voiced for seated listening- stand up and there's a shift in perspective that, while relatively minor, I found slightly disconcerting. This isn't the huge tonal change you get with some loudspeakers, but rather a shift in the soundstage. Seated, I was surrounded by the stage, looking into it in front of me. When I stood, the soundstage shrank. It seemed as if I was looking down into it from a balcony. This may not bother everyone as much as it did me, but some performances draw me to my feet -- and such a change in perspective takes me out of the music for an instant. Bummer.

It would be tempting to blame this on the top plate, which is only 4.5" above the tweeter and just has to affect its dispersion. But it could be a crossover artifact instead.

Associated Equipment

LP playback: Linn LP12/Lingo/Cirkus/Ekos/Arkiv.
CD playback: Audio Research CD2/DAC3, Linn Sondek CD12, Sonic Frontiers Transport 3/Processor 3.
DVD player: Denon DVD-3000.
Preamplification: Audio Research Reference One, Conrad-Johnson ART, Mark Levinson No.380S; Linn Linto phono section.
Power amplifiers: Accuphase M2000, Audio Research VT200, Cary CAD-805C, Mark Levinson No.332.
Cables: AudioQuest Lapis, Madrigal CZ-Gel 1, Siltech SQ-80B G3.
Accessories: API Power Wedge Ultra, Cinemedia PowerPRO 20 AC line balancer, OSAR equipment and amplifier racks.
Room treatment: ASC Tube Traps, Studio Traps, Bass Traps; RPG Abffusors; rasorial critter.

-WesPhillips

The philosophers have only interpreted the world in various ways; the point is to change it.
I recently reviewed the B&W Nautilus 801 (January 1999, Vo1.22 No.1), whose $11,000/pair price is quite close to the Circe's $12,000/pair. Both speakers are quite sensitive to the ancillary components that must be used with them. But the two speakers sound quite different from one another, and I don't imagine they'll appeal to the same listeners. The B&W is dynamic as all get out, and can play loud enough to cause structural damage. The Alón did a superb job of presenting dynamic contrasts and shadings, and played plenty loud enough for me - even in head banging moods -- but didn't convey the same sense of unlimited dynamic potential as the N801. This is an area where different people will react according to their nature. Not everyone needs to peel the paint off their walls with sheer loudness.

The Alón Circe has a midrange and high-frequency purity that is nothing short of magical.

Allied with this sense of greater loudness potential, the B&Ws also seemed to possess greater volume in terms of soundstage size. The N-801s just projected more sonic real estate. The Circes' soundstage was detailed and densely packed with information, but felt more constrained.

The B&W to my ears, has a tauter leaner, more muscular bottom end. The Circe's generous bass is extremely supple and tuneful, but it is warm and, perhaps, a shade less well defined. Again, a matter of taste.

To use a visual analogy, the differences between the two speakers struck me as similar to the difference between videotape and film. Videotape has a "realness" that is not to everyone's liking. Edges are sharply defined, and colors don't have the rich saturation they have in film, while light has a starkness that seems harsh in comparison to film. The B&W seems to me similar to videotape -- no one can deny that it depicts reality, but some folks might wish the edges weren't quite so ungiving. The Alón also reflected reality, but colors were subtler -- richer, some would say -- and the illumination was often softer.

I wish I could pick and choose qualities from the two, but that would create a third speaker, one not under review here. Ultimately, I'd go with the Nautilus, but I truly do comprehend the Circe's transformative magic.

How strange the change from major to minor every time we say good-bye.
Some experts take great glee in pointing out that a loudspeaker is the least perfect component in the audio chain, but lately I've come to the conclusion that what they really mean is that the speaker is the most personal link in that chain. Speakers are what we listen to when we listen to a hi-fi; they are the component in which design perhaps comes closest to being an art, not simply science.

The choices that went into designing the Alón Circe have produced a speaker that I respect rather than love, but I can see where that could go the other way for another listener. It has a midrange and high-frequency purity that is nothing short of magical, mated to deep, well-tuned bass that I found a trifle warm, but that someone else might well find enchanting. At this level, speaker choice is truly a matter of personal taste.

But if you're a tube-using music lover with a yen for '60s jazz, the Alón Circe just might be the closest thing to a time machine you'll ever hear. With the right system and the right music, you can easily ask yourself, "How could it get any better than this?"

Measurements

The big Alón's sensitivity was to specification at an estimated 87dB(B)/2.83V/m. Its impedance plot of magnitude and phase against frequency (fig. 1) dropped below 6 ohms only in the upper bass and upper midrange, with a moderate phase angle across most of the band other than in the bass. The Circe will be relatively easy to drive, which presumably explains why listeners have had success using the speaker with SE triode amplifiers. But note the very high impedance peak at 39Hz: 24 ohms. This will exaggerate the midbass with such amplifiers. It also indicates that the quite large sealed bass bin is tuned relatively high in frequency, which will impact ultimate bass extension.


Fig. 1 Alón Circe, electrical impedance (solid) and phase (dashed).
(2 ohms/vertical div.).

Some wrinkles can be seen in the impedance traces between 180Hz and 240Hz and at 26kHz. The latter is associated with the metal-dome tweeter's "oil-can" resonance and should be subjectively benign. However, the former indicates the presence of some cabinet resonances in the lower midrange. Fig 2., for example, shows a cumulative spectral-decay plot calculated from the output of a plastic-tape accelerometer fastened to the center of a cabinet side panel. A very strong resonance can be seen at 207Hz, with two more just above and below that frequency. All things being equal, I would have expected this behavior to add an over-warm chesty quality to spoken male voice. As Wes Phillips didn't note any problems in this region in his auditioning, I must assume this cabinet problem looks worse than it sounds.


Fig. 2 Alón Circe, cumulative spectral-decay plot of accelerometer output fastened to bass-cabinet
side wall (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2 kHz.)


Fig. 3 Alón Circe, crossover electrical drive signals to the three
drive-units, measured at the speaker terminals with the crossover
loaded by the three units.

Because of the Circe's external crossover, it was possible to do a more through analysis of the crossover behavior than usual. Fig. 3, for example, shows the actual electrical drive signals supplied to the three drive-units. The electrical crossover frequency between the woofer and the midrange unit appears to be around 550Hz rather than the specified 400Hz, while that between the midrange and tweeter is 4.2kHz. The actual acoustic crossover points will be different from the electrical ones, due to the differing drive-unit sensitivities, of course. The tweeter has an overall rising drive signal over most of its passband, while the woofer driver peaks by 2dB around the cabinet tuning frequency, suggesting some series resistance in its path. The rolloff slopes are approximately first-order, other than the midrange unit's low-pass slope, which is second-order.


Fig. 4 Alón Circe, response at 50" of woofer without crossover (top)
and with (bottom) both curves corrected for microphone response.


Fig. 5 Alón Circe, response at 50" of midrange unit without crossover (top)
and with (bottom), both curves corrected for microphone response.


Fig. 6 Alón Circe, response at 50" of tweeter without crossover (top)
and with (bottom), both curves corrected for microphone response.

Figs 4, 5, and 6 compare the raw drive-unit response with the response as filtered by the crossover for the woofer, midrange unit, and tweeter, respectively. Without any equalization, the woofer's output extends up to the presence region (fig.4), with then a very sharp rolloff. The crossover both pads down the woofer's level and starts to roll off its output above 600Hz. The midrange unit, too, has its level dropped by the crossover (fig.5), With its output gently rolled off above 4kHz. A sharp spike in the unequalized output can be seen at 9.5kHz; this is suppressed by only about 8dB compared with the reference level at 1kHz. Note also the peaks and dips between 1kHz and 2kHz in the midrange unit's output. This unevenness will be due to the unit's acoustic environment - the dowels are probably too small in diameter to present an acoustic obstacle in this frequency region, but the top plate and the top of the bass enclosure should produce strong reflections.


Fig. 7 Alón Circe, acoustic crossover on tweeter axis at 50", corrected
for microphone response, with the nearfield woofer and midrange
responses plotted below 355Hz and 600Hz, respectively.

A similar effect can be seen in both the equalized and raw responses of the tweeter (fig.6). Note that the HF unit is still putting out significant energy for two octaves below its nominal passband, due to the crossover's slow-slope high-pass filter. This can also be seen in fig.7, which shows the Circe's overall acoustic crossover. The crossover between the woofer and midrange appears to lie almost an octave higher than specified. While the midrange unit and tweeter do cross over at the specified 3.5kHz, there is significant overlap. The sharp dip and peak at 26kHz in the tweeter's output are due to the resonance mentioned earlier. The peak between 40Hz and 60Hz is due to the woofer tuning, with a 12dB/octave rolloff apparent below that region.


Fig. 8 Alón Circe, anechoic response on tweeter axis at 50", averaged
across 30" horizontal window and corrected for microphone response,
with the nearfield woofer response plotted below 300Hz

Fig.8 shows how these individual responses add up on the tweeter axis at a distance of 50". The shape of the curve is basically triple humped, with peaks and dips roughly 4dB either side of the median line, and the suckout in the high midrange most pronounced. How this response will be perceived is hard to predict, as it will depend very much on the music program whether the listener notices peaks as excesses in energy or the dips as energy deficiencies. In my own auditioning, when the speakers were being driven by the Cary amplifiers I kept latching on to the octave-wide plateau between 500Hz and 1kHz, which I felt added a slight megaphone-like quality to the balance. On the plus side, it will emphasize recorded detail.


Fig. 9 Alón Circe, lateral response family at 50", from back to front: responses 90° - 5° off-axis, response
on tweeter axis, responses 5° - 90° off-axis.


Fig. 10 Alón Circe, lateral response family at 50", normalized to reponse on tweeter axis, from back to front:
differences in response 90° - 5° off-axis, reference response, differences in response 5° - 90° off-axis.

But the speaker's perceived in-room balance will also be influenced by the way it behaves off-axis. Fig.9 shows the Circe's response plotted from 90" on one side of the tweeter axis to 90" on the other. This graph is hard to interpret, so I have also shown these same curves with the on-axis response subtracted from each (fig. 10). Between 300Hz and 1 kHz, the speaker's dipole nature can be clearly seen, but from 1 kHz to 6 kHz the Circe has wide, even dispersion. In effect, the lack of upper-midrange energy seen on-axis fills in to quite an extent to the speaker's sides. The larger the room and the farther away the listener sits, the better balanced the Alón's midrange and treble will sound. Conversely, the closer the listener sits and the drier the room acoustic, the more bothersome the discontinuity in the on-axis response will become.


Fig. 11 Alón Circe, vertical response family at 50", from back to front: responses 10° - 5° above HF axis,
reference response, responses 5° - 15° below HF axis.

Wes did comment on some changes in the Circes' soundstaging as he changed his listening height. In the vertical plane (fig. 11), big suckouts appear in the speaker's upper crossover region for extreme off-axis angles. But smaller changes in listening height affect the integration between the midrange unit and tweeter. In fact, I got the flattest on-axis response just below the tweeter, around 40" from the floor.


Fig. 12 Alón Circe, impulse response on tweeter axis at 50"
(5ms time window, 30 kHz bandwidth).


Fig. 13 Alón Circe, step response on tweeter axis at 50"
(5ms time window, 30 kHz bandwidth).


Fig. 14 Alón Circe, cumulative spectral-decay plot at 50" (0.15ms risetime).

In the time domain, the Circe's impulse response (fig.12) is dominated by the tweeter's ultrasonic ringing. However, some reasonably strong reflections can be seen in this graph at between 1.5ms and 2.5ms after the initial impulse. These can be more clearly seen in the speaker's step response (fig.13); as I said above, I suspect these are due to the midrange unit's sound bouncing back from the top plate and the top panel of the bass enclosure. The step response also shows that the Circe is not a time-coherent design, despite its gently sloped-back baffle and its use of what appear to be first-order crossover filters. While the tweeter and woofer are connected with positive acoustic polarity, the midrange is wired out of phase to give the best amplitude-response integration between it and the other two units. As a result of the strong early reflections, the Circe's waterfall plot (Fig. 14) looks hashy. But this should not be misinterpreted as indicating the presence of resonances. Only the ridge of energy associated with the tweeter's ultrasonic peak is a true resonance.

These enigmatic measurements lead me to suspect that the Circe is very fussy when it comes to optimizing setup and room placement. However, as Wes found, with enough care taken, the result can be very musically satisfying. -John Atkinson