2018 HIFI+ CCi
"The thing about this system is even at its entry point as discussed, it’s more than good enough." Alan Sircom has reviewd a complete Crystal Cable system for Hifi + magazine.
Crystal Cable system by Alan Sircom
As the name suggests, Crystal Cable is best known for its range of interconnects, loudspeaker cables, and power cords. However, keeneyed readers will note that the brand has spent all of this decade manufacturing loudspeakers, and for the past few years has been showing a distinctive amplifier (and plinth-like subwoofer) at Munich, Las Vegas, and more. Finally, that system is ready for prime-time. However, unlike the other systems tested in this issue, we took a step-by-step approach to assembling our Crystal system. We stayed with the basics: amp, speaker, and cable, although in this case it meant CCI integrated amplifier, two flavours of two-way loudspeakers, a clever little hat thing that sits on top of those loudspeakers, a subwoofer/ loudspeaker stand, two ‘families’ of cable, and everything south of the dCS front end used by Crystal all made by the brand and all made in the company’s factory just outside of Arnhem in the Netherlands. Each of these steps along the way made a tangible and material difference to the performance of the system – some more significant than others.The rationale for the whole system approach is not the usual one. The company – joined at the hip to Siltech – isn’t making loudspeakers to make an impact in the loudspeaker market; it’s instead to deliver a design that’s both revealing enough to showcase what the loudspeakers can do and is as musically rewarding as Gabi from Crystal Cable might choose for her home listening. That’s the joy of both owning an audio brand, and having a husband who is one of the sharpest tools in the audio box; the world is your oyster. Rather than make follies or one-off projects for personal use, we all get to benefit!
“That’s the downside of having the sharpest tool in the audio box on tap... the search for perfection means never signing off the design.”
The place to start is the newest addition to the Crystal Cable line-up, the CCI (or Crystal Cable Integrated) amplifier. Well, newest in terms of product launches; the amplifier has been on display and on show at audio expos for several years, going through a few perfectionist final tweaks (and that’s the downside of being having the sharpest tool in the audio boxon tap... the search for perfection means never signing off the design). The amplifier itself is a cube about the size of a medium-sized two-way standmount and is
deceptively clever. The compact, cuboid chassis of the CCI amplifier is there for a reason: it delivers both space and thermal efficiency. So despite its 100 Watt/ channel rating in Class AB, its cooling design and extensive protection means that the Cube chassis runs cool enough that it can be placed almost anywhere. Where it gets really fun is in the use of an optically-decoupled, standing bias, Class AB design. If the phrase ‘optically-decoupled, standing bias’ rings a bell, it’s because the circuit is derived from Siltech’s revolutionary Light Drive output stage used in its air-gaspingly expensive SAGA amplifier. CCI’s fully-balanced line-stage offers six inputs, each with individual gain settings, while software controlled relays totally isolate unused source components for optimum sound quality. Each stage of the amplifier, as well as the control circuitry, has its own independent, dedicated power supply. These are sophisticated Power Factor Corrected switch-mode designs, fully enclosed and heavily shielded. In short, don’t let the size fool you; this is one serious amp design. Crystal Cable’s first loudspeaker was the tower Arabesque Glass (which is still in production almost 10 years after its introduction). Subsequent designs (including the Minissimo) have been scaled down from that tall, glass tower, but feature very similar design principles. And those design principles are sticking closely to the parameters expressed by COMSOL Multiphysics, the modelling software used by the company. And, by treating the air inside and outside a loudspeaker as a gas (because, well, it is a gas), and using COSMOL’s gas-dynamics package, Crystal Cable has created a design that has a natural resonant delay due to cabinet structure and not a forced resonant delay from cabinet damping. For the basic Minissimo, Crystal Cable uses the same ScanSpeak Illuminator drivers it used in the Arabesque Mini; a 25mm beryllium tweeter and 150mm laminated cone paper mid-bass design, with the port firing downward, and a one-piece block matrix cabinet of resin and metal, from which the basic Minissimo shape is milled. The last piece in the Minissimo jigsaw is the crossover, an updated variation on the theme of a second-order network that Crystal Cable calls its ‘Natural Science’ crossover. This is designed to create a 12dB/octave slope while trying to minimise phase and time domain distortions. This means no nasty low impedance dips, and means that while the Minissimo is 3dB down at 48Hz, the slope is very gentle and is only -6dB down at 38Hz. At the other end of the scale, the tweeter extends to 38kHz and the crossover point is 1.8kHz. The trade-off is 86dB sensitivity. “That’s the downside of having the sharpest tool in the audio box on tap... the search for perfection means never signing off the design.”
“Because it’s a great track, Jim Reeves has a lovely voice, and a friend probably buried his father’s horse to the song once upon a time.”
The Minissimo doesn’t stop there. There’s an uprated model called the Minissimo Diamond. Crystal Cable and SEAS developed a diamond tweeter design that improved high-frequency performance over the standard Minissimo while retaining in-phase output across both drivers. This loudspeaker is further improved by pair-matching the bass units, adding custom-designed capacitors in the crossover, adding bi-wire terminals, reworking the cabinet damping, and rewiring the internals with the firm’s top Absolute Dream cables. There is also a top-plate baffle and mass-loading device specifically for the Minissimo and Minissimo Diamond. Called the Scala (after the opera house, of course) its 3D shape is machined from a solid billet of aluminum. The staircase shape is modelled once again using COMSOL physics. Its acoustic behaviour is also modelled carefully to further improve the sound of Minissimo series speakers, by extending the baffle and thereby moving the baffle step further from the tweeter. This is a potential add-on at any time, to either Minissimo model, and in listening it definitely justified its place in the system. The last component in the chain was the Submissimo subwoofer. Featuring horizontally opposed 330mm drivers are arranged in a force-cancelling configuration, each driven by its own independent power amplifier. Rather than using electronic equalization to extend low-frequencies, it compensates for non-linearities and variations in the drivers themselves. The enclosure itself is a curved wall composite construction, designed to absorb and dissipate the drivers’ unwanted mechanical output before it can feed back into the acoustic output, distorting timing, pitch, and textural information in the process. This also makes the top-plate inert, allowing a pair of Submissimos to take over the role of loudspeaker stands. We could only muster one. We started the listening session with Crystal Cable’s lone ‘off-the-reel’ Special series cables, in loudspeaker, interconnect, and power cord form. They use high-purity silver-gold alloy and silver-plated oxygen-free copper conductors, and although Crystal Cable provides the hardware, this is designed to be finished in store. At Special level, with the standard loudspeaker and no subwoofer in the mix, the system had an extremely light touch; not lightweight, but deft and delicate. It’s very audiophile, but ‘The TennesseeWaltz’ played by Allan Taylor [Hotels and Dreamers, Stockfisch], gave the perfect example of what this system does best. Just him, his guitar, and a slide Dobro. OK, this can sound impressive played through a clock radio, but what the Crystal system does is make it musically communicative. Extremely musically communicative. It has surprising bass too, for small instruments played through small loudspeakers, to the point where you think at least one of those small things is a lot bigger in reality. But it’s the musicality that makes it score so highly. It’s clear this system is not simply a technical exercise, but a set of devices born out of sheer passion for music. Normally that would sound trite, but with Gabi Rijnveld’s child prodigy musical background, it rings true. It’s strange that a system that is designed as a platform to show up changes in cables is so comfortable playing with the company’s entry-level cables. The sound has dynamic range, energy, flow, and is extremely musical (that word again... get used to it). And yet, it’s more than that. It’s a system that invites you to listen to a really diverse range of pieces of music, like ‘Adios Amigo’ by Jim Reeves [RCA single]. Because it’s a great record, Jim Reeves has a lovely voice, and a friend probably buried his father’s horse to the song once upon a time. It’s that sort of system. You’d expect it to be more overtly resolving of difference.
That is, until you change something. Then you realise that on top of that layer of wonderful, effortless music, there’s something extraordinarily insightful playing. We stepped up the pace by adding the little Scala ‘hat’ to the Minissimos. This added greater width to the soundstage and made the mid and upper end frequency range seem considerably more engaging – on a system that was already extremely engaging in and of itself. I could have gone back to playing Jim Reeves over and over again, but moved over to ‘Chan Chan’ by the Buena Vista Social Club, from the album of the same name [World Circuit]. This had an additional sense of effortlessness compared to its Scala-free playing. Those old Cuban musicians really chugged along with an infectious rhythm, but what the Scala did was help you listen into the sound of EGREM Studios in Havana at the end of the 1990s so rich and atmospheric was the sound.
Having improved the treble, it was the turn of the bass, with the addition of a single Submissimo between the speakers. This made it a perfect plinth for the CCI amp. We played ‘Father Lucifer’ by Tori Amos from her Boys for Pele album [East West]. Not the best known track on the album, but its combination of her slightly thin sounding piano, breathy vocal, and very percussive playing style, with that distant horn playing in the second verse makes it a very subtle track to use with a sub. If the sub integrates well, it will sound like Tori Amos at her piano. If it doesn’t it will sound like Jerry Lee Lewis covering a Tori Amos track. No filler, and no killer here! The Submissimo integrated perfectly. Other, more typical tracks in my arsenal of listening tests (King Curtis for example) showed the Submissimo has substance as well as lightness of touch. The best praise I can heap on any subwoofer applies here; it made a good speaker sound bigger and better. Now it was time for a cable change, and we upgraded the full set of Special Cables for Micro Diamond. Regardless of cable type, Micro Diamond uses annealed gold/silver alloy conductors, helically wrapped in a dual layer of ultra-thin Kapton foil as a shield. The different use cases in audio demand more or less conductors, but the basic properties of the cable remain the same. We’re cooking on gas now. Out came tracks that never see the light of day normally, like ‘Stella by Starlight’ from Joe Pass’ Virtuoso album [Pablo]. This album lives up to its name and Pass’ chord voicing and solo technique leavesjazz guitarists speechless. It’s not a good recording to play because the jazz ennui that strikes any guitarist (no matter how good or how long it’s been since they picked up a guitar), but also because on a less than perfectly poised system, it can be mistaken for jazz noodling (it goes on a bit) usually because some element in the system is a bit too enthusiastic (or too unenthusiastic) with its legato, and it either sounds too ‘choppy’ or ‘blurred’. Here, his impossibly perfect playing is presented in all its glory. Damn him. Around this time, I jotted down a couple of badly repetitive lines that encapsulate the whole listening process with Crystal Cable’s system: “musically speaking, this is one of the most musically musical systems to play music through. It’s musical integrity is only bettered by its ability to resolve the musical intent of the music playing.” You get the drift! Other, more typical tracks in my arsenal of listening tests (King Curtis for example) showed the Submissimo has substance as well as lightness of touch. The best praise I can heap on any subwoofer applies here; it made a good speaker sound bigger and better.
Now it was time for a cable change, and we upgraded the full set of Special Cables for Micro Diamond. Regardless of cable type, Micro Diamond uses annealed gold/silver alloy conductors, helically wrapped in a dual layer of ultra-thin Kapton foil as a shield. The different use cases in audio demand more or less conductors, but the basic properties of the cable remain the same.
“What sounded child-like and screechy became soaring and powerful. So it was with every track played on the Minissimo Diamonds.”
The last part of the system update was to move to the Minissimo Diamond speaker. At this point we are really cookin’. This system moved into a new level. It retained all the good points (yes, that includes sounding ‘musical’... but that was so-o-o last page), but now started to demonstrate the sort of sophistication, elegance, and high-end ‘sheen’ (in a positive way) that separates the good from the great. Curiously, the biggest change in improving the tweeter was a clearer and more defined bass, and more natural midrange. I played with moving the Scala ‘hat’ on and off at this point, and felt under the circumstances it was wholly appropriate to listen to some Maria Callas, although this time singing Mozart. I’d played this track several times during the listening test and it was clear Callas was outside her comfort zone. Her voice was forced and pinched. It was still her, but not the best of her. But on the Diamonds (with the Scala in place, naturally), it was Callas again. What sounded child-like and screechy became soaring and powerful. So it was with every track played on the Minissimo Diamonds. We didn’t get to the end-point… not even remotely. The cables increase the performance of the system as we move from silver-gold to monocrystal and improve the lot of the whole shebang as the number of monocrystal conductors increase. We are also using just the one subwoofer, where two (one acting as a stand for each speaker) would be even better. The reason why these next steps remain untrammelled is part pragmatism (there was no second subwoofer available to test) and part practical (swapping out the already quite spendy Ultra Diamond cable for Absolute or Ultimate Dream could easily quadruple the cost of the whole system, which no-one in the real world is ever going to do). As it is, the refinement of the diamond tweeter, the subwoofer, and the cable change all take a substantial toll on the wallet of the owner, adding considerably more to the overall cost of the system. It’s hard to pick out one component in all this for additional praise, as each step in the chain made a sound that you would struggle to think came from so small a system, but the next step made it even better. However, if it were just the one to choose, I’d probably go with the amplifier. It was a constant companion throughout the whole test, it harnesses a lot more of the performance of the extraordinary SAGA than a solid-state cube has any right to do, and it would never run out of steam at all during the test. But this is a close-run thing. I could just as easily find the Diamond loudspeakers (with the Scala) to be the best, and of course there are those excellent, svelte, cables...The thing about this system is even at its entry point as discussed, it’s more than good enough. I suspect the reality is few will stay at this level. This is as much a proof-of-concept for Crystal Cable’s cable designs as it is a fine sounding system in its own right, and I suspect many of those who buy this system would never dream of staying with the basic cables used at the start of this test.Back to overview