Crystal Cable Arabesque Minissimo Diamond loudspeaker
I've known the Dutch engineer Edwin Rijnveld since the 1980s, when he founded the Siltech cable company. I was impressed by the expertise evident in both the Siltech SAGA two-chassis amplifier, reviewed by Michael Fremer in our October 2014 issue, and in the expensive, glass-enclosure Arabesque speakers Edwin designed to be produced under the brand name Crystal Cable, run by his wife, Gabi. I was talking to the Rijnvelds at a dinner they organized last January, at the 2016 Consumer Electronics Show, to honor musician Graham Nash, who was attending the show on Stereophile's behalf. When they suggested I review the newest Crystal Cable speaker, the stand-mounted Arabesque Minissimo Diamond ($19,995/pair with stands), I didn't have to be asked twice.
The Arabesque Minissimo Diamond
The Diamond uses the same enclosure as the original Arabesque Minissimo: a small two-way speaker, introduced in 2014, that uses a unique thin-wall enclosure featuring, other than a flat front section for the drive-units, continuously curved side and rear walls. Viewed from above, the Minissimo's cabinet resembles a serifed font's comma lying on its side. The monocoque enclosure is milled from a single piece of aluminum-loaded polymer, with both the curvature and thickness of the walls optimized using Sweden's sophisticated COMSOL Multiphysics app. As there are no parallel surfaces other than the top and bottom panels, the cabinet shape minimizes the production of internal resonances; just as important, the absence of any sharply defined acoustic discontinuities around the drive-units eliminates disturbances and reflections of the radiated wavefronts.
The tweeter is made by SEAS. As its name implies, the Diamond edition replaces the original speaker's beryllium-dome tweeter with a 1" diamond-diaphragm dome developed in conjunction with Crystal Cable and using a silver voice-coil. The fragile dome is protected by a laser-cut, acoustically transparent grille. The 6" woofer, made by ScanSpeak to Crystal's specification, remains unchanged, with a tri-lobed emblem pressed into the 4"-diameter, laminated-paper cone, though Crystal Cable now matches each pair's drive-units to within 0.3dB. The woofer is reflex-loaded by a downward-firing, 1"-diameter port in the speaker's base.
There are also significant improvements inside the Diamond Edition: monocrystal silver internal wiring, WBT NextGen silver biwire terminals, and a different crossover topology called Natural Science, claimed to maintain true in-phase output from the drivers. The crossover filters use non-inductive silver-in-oil capacitors, 5" carbon resistors, and "multistranded, perfect-lay, hexagonal winding, air-core, vacuum-impregnated" inductors.
The speaker's enclosure is finished in automotive gloss paint and the two speakers of each pair are mirror-imaged. The speaker is permanently fixed to its stand, this comprising three damped, chromed tubes and a heavy base embossed with the enclosure's "comma" profile. Carpet-piercing spikes are provided; I used them.
The Arabesque Minissimo Diamond's manual suggests that placing the mirror-imaged speakers so that the larger curved sidesthe commas' tailsface outward gives the deepest soundstaging, so that's how I set them up. Reversing these positions is said to work better in wide rooms. The manual recommends a listening distance of 1 to 1.5 times the distance between the speakers; in my room, the tweeters were 78" distant from one another and 101" from my ears, with the speakers toed in to the listening position. The left and right speakers were 38" and 50" from their respective sidewalls, this asymmetry due to the right-hand side of my room having a raised section behind the speaker with two stairs leading up to the vestibule, which gives the right and left speakers different acoustic environments.
Crystal recommends a distance of at least 12" from the wall behind the speakers, with 24" being optimal. Unfortunately, this wasn't possible in my room, as my equipment racks stand against that wall. I experimented with various placements and ended with the woofer dustcaps 80" from the wall behind the speakers, which is close to where KEF's LS50s performed best in my room. Despite this, the low-frequency, 1/3-octave warble tones on Editor's Choice (CD, Stereophile STPH016-2) were still reproduced in good measure down to the 63Hz band, with the 50Hz and 40Hz tones shelved down and the 25 and 20Hz tones inaudible.
But the definition of bass instruments was excellent. The low-pitched drums and bass marimba notes in "I Say," from Happy Rhodes's HR>5 (16/44.1 ALAC, Aural Gratification), had sufficient weight and were well differentiated, despite occupying the same pitch space. Charlie Haden's double bass in his solo in "Turnaround," from Jim Hall/Charlie Haden (CD, Impulse! B002176502), had an excellent combination of body tone and attack, though it sounded perhaps a bit too rich in the upper bass. And Pino Palladino's Fender bass in the slow blues "Out of My Mind," from the John Mayer Trio's Where the Light Is: John Mayer Live in Los Angeles (16/48 ALAC file ripped from DVD-V, Sony 8697-722727-9), sounded both impressively even and in full measure.
Bass guitar and double bass don't produce any energy below the midbass, so to test how much low bass was missing, I played a recording I'd made of Jonas Nordwall performing the Toccata of Widor's Organ Symphony 5, which has high levels of energy below 40Hz (24/88.2, AIFF file). The lowest notes were indeed missing in action, even though the woofers' excursions looked to be around 0.5" peakpeak. (The maximum linear excursion) is 0.75".) More significant, the Minissimo Diamonds opened a deep, well-defined, transparent window on the acoustic of the First United Methodist Church of Portland, Oregon.
The Crystal speaker's excellent imaging and clarity were a consistent factor throughout my auditioning. The half-stepspaced tonebursts on Editor's Choice spoke very cleanly, with no discontinuity between the ranges handled by the woofer and tweeter. Though the woodwind countermelodies in Rachmaninoff's Vocalise, with Iván Fisher conducting the Budapest Festival Orchestra (DSD64 file, Channel Classics), were set well back in the soundstage, they were readily audible without any feeling that they were being spotlit. When I listened to the dual-mono pink-noise track from Editor's Choice, the Crystals reproduced a narrow central image with no splashing to the sides, and the image of my Fender bass in this CD's "Channel Phasing" track was locked firmly in space.
When it came to tonal quality, getting a handle on the Minissimo Diamonds was less straightforward. Pink noise revealed a slightly midrange-forward balance, though the treble was smooth and free from coloration. This was with my ears level with the tweeters, which are 36" from the floor. The balance didn't change significantly as I raised my head a few inches, but a hollow quality became evident when I stood up. Both the John Mayer track and Rachmaninoff's Vocalise sounded a tad mellow, particularly with the sweet-sounding First Watt J2 amplifier, reviewed by Herb Reichert elsewhere in this issue. By contrast, the top octaves of the cymbals in "A Cockeyed Optimist," from the Fred Hersch Trio's Sunday Night at the Vanguard (CD, Palmetto PM2183), didn't sound rolled off, whereas the midrange of the piano was a little too prominent.
The midrange of Robert Silverman's Steinway in his performance of Beethoven's Diabelli Variations (16/44.1 ALAC file, Stereophile STPH017-2) was also a little forward, but this recording sounded surprisingly dynamic. In the fugue of Variation 32, when Silverman pounds out the theme with his left hand, the Minissimo Diamonds sounded larger than they are. This was with the Pass Labs monoblocks; but with the First Watt J2's low 20dB gain and the Crystals' low sensitivity, I could get only just enough loudness, the peaks measuring around 93dB (Studio Six SPL meter app set to C-weighting and Fast). The speakers ran out of steam with the First Watt with the John Mayer track and with September's "Recording of the Month," Van Morrison's . . It's Too Late to Stop Now . . . Volumes II, III, IV & DVD (CD, Exile/Columbia/Legacy 8887513474). If these speakers are to sing, they need more than 25Wpc.
At a hair less than $20,000/pair, Crystal Cable's Arabesque Minissimo Diamond is very expensive for a small two-way loudspeaker. However, it looks drop-dead gorgeous, sounds superb when matched with an appropriate amplifier, and though the low bass is absent, it has a more convincing low-frequency balance than you'd expect. If your pockets are sufficiently deep, give it a listen.