⌈ CRYSTAL CABLE is a brand owned by INTERNATIONAL AUDIO HOLDING, along with the Siltech brand. It is a specialty manufacturer offering cabling, from interconnects to headphone and AC power cables, and also has a line of speakers. The chief engineer of both brands is Edwin van der Kley-Rijnveld, who puts his ideas into practice this way. However, the "face" of Crystal Cable is Gabi van der Kley-Rijnveld. We are testing her MINISSIMO FORTE speakers. We are testing them as the first in the world. ⌋

˻ PREMIERE ˼

T IS NOT COMMON that a company specializing in other sectors of the audio industry makes also loudspeakers. It happens, of course, and there are also companies trying to have a "complete" offer so that a customer can buy an entire, or almost entire, system from them. This mercantile approach is not so pointless, after all, because in this way the company can optimize the individual components so that they work with each other under the most favorable conditions possible.

But there is a second group of manufacturers, much smaller, for whom such additional products are needed for the development of their basic products, they are to be a reference for them. And because a lot of work and even more money was involved in their development, to compensate at least partially for it, they become available to customers. It is never possible to fully reimburse the costs of their development, but they can be significantly compensated in this way.

Just as a quick aside, what comes to mind are PS Audio, a company specializing first in power supplies and then in digital sources and amplifiers, for which the Aspen FR30 speakers were the way to complete their own system, and Ayon Audio, which is pursuing ideas for advanced speaker systems and even a turntable at sister company LumenWhite.

If I were to think about it, right next to them should also stand International Audio Holding, owner of the Siltech and Crystal Cable brands. Back in 1998, the former offered the unconventional SEPA amplifier, based on unusual tube technology, followed by the powerful Pantheon XXV loudspeakers. Crystal Cable, the CCi amplifier, and Arabesque loudspeakers also have their "reciprocity". Introduced in 2009, costing €45,000 at the time, they brought a sophisticated realization of the idea of glass-enclosed speakers.

Their secret was the proper shape of the baffles, which avoided standing waves and most importantly reduced resonances, so that the walls of the speakers did not need to be damped. Arabesque introduced into Crystal Cable's "vocabulary" a specific shape, with one wall curled back. To design such a zigzagged profile, Edwin Van der Kley used not only classical computer programs, but also COMSOL Multiphysic software, assisted by Frank de Pont, who was part of the team that wrote it.

Doug Schneider, editor-in-chief of the "Soundstage!", wrote about the software:

COMSOL is a multiphysics software application that, with sufficient technical knowledge, can be used to simulate anything before it actually gets built. NASA Technical Briefs Magazine, an official NASA publication, voted it Product of the Year in 2006. NASA researchers use it to simulate some of their most ambitious projects before they ever get made. However, this isn't a product for a do-it-yourselfer. Despite having post-secondary education in computer science and working in the computer field for 13 years, I am incapable of using this program. Furthermore, it's a "tool" that requires a thorough understanding of physics to make use of it. It's used in the aerospace and auto industries, and can be used almost anywhere else you can think of where real physical products integrate with the real world.

⸜ DOUG SCHNEIDER, Amsterdam, Arnhem and the Arabesque, "Soundstage!", January 2009, → www.SOUNDSTAGENETWORK.com, accessed August 3rd 2023.

The COMSOL system is extremely expensive, and at the time its use cost a small fortune. Not surprisingly, its use in audio was rare, and Edwin's designs were among the absolute exceptions. He made his first statement by designing Phanteon loudspeakers, and then used it for the Arabesque and subsequent smaller Crystal Cable loudspeaker designs.

▌ MINISSIMO FORTE

MINISSIMO FORTE SPEAKERS are stand-mounted, two-way bass-reflex speakers with a hybrid active-passive crossover. They are integrated permanently into the stands, and they require not only a music signal, but also an AC power supply to operate. However, they are not active speakers, which we will come back to.

At the same time, they are the latest model in Crystal Cable's long series of stand-mounted speakers. After all, Arabesque received a partner in the form of the small Arabesque Mini speakers, followed by Arabesque III, and then Minissimo, Minissimo Diamond and finally the Minissimo Forte speakers we tested. The series is complemented by a subwoofer and Scala - a component laid on top of the speakers.

⸜ CABINET The MINISSIMO FORTE repeats the shape developed for the top speakers in 2009. Although the front panel is flat, the sides are rounded, and one of them is curled back. The enclosure is made from a block of aluminum; previously it was a mix of resin and metallic powder. The Forte model managed to further refine the exterior and external shape, so that, as Edwin told me, the enclosure hardly vibrates at all.

Attention is drawn to the complex internal shape - instead of smooth baffles, they are covered with something like "ridges", as if a module used to modify room acoustics had been integrated into the speakers. It bears the company's name MAD (Multiple Absorption and Dispersion). Company materials say that breaking up resonances "allows the drivers to play, not the cabinet," and the result is said to be "coloration-free, crystal-clear sound with an incredible amount of detail." The rear panel also features circular decoupling elements for the speakers and stands.

As I said, the stands are integrated with the speakers, they are one unit with them. They are shaped like a tall column with a flat back panel. The Minissimo Forte have been fixed so that they seem to float in the air. The speaker features the most important technical innovation of these designs and one of Siltech's most important innovations - a hybrid active-passive crossover.

⸜ CROSSOVER I don't know if you remember, but when visiting the Siltech and Crystal Cable factory in Elst, in the Netherlands (more → HERE), one of the highlights was listening to the flagship Symphony speakers and the Minissimo Forte prototype. The latter were still classic bookshelf speakers, but with an external device to which speaker cables were connected and which was powered from the "wall".

Normally, we would say that this is an active or semi-active speaker (like Arabesque). However, the tested model is a classic passive design, with a large passive crossover, only that it is balanced. This is possible because a buffer amplifier is placed in front of it. It has a gain of 1, so it only provides current, not voltage. As Edwin says, this is one of his more important developments in years. The crossover was assembled with nice oil capacitors from Mundorf, and the NC122MP series NCore amplifier was purchased from Hypex Electronics. It is a class-D amplifier with a switching mode power supply.

This design allowed eliminating all the coils from the crossover that are an issue of passive designs. Another important feature of this circuit is that the amplifier "sees" a 16 ohm load (as in designs from the 1950s and 1960s, rather than 8 or 4 ohms. It also managed to achieve a very high efficiency, as high as 95 dB/2.83 dB. The manufacturer says that 15 watts is enough to drive them, but it can also be 150, it all depends on what you want to achieve. And another advantage is the ultra-low distortion of 0.2%, while in classical speakers this level is an order of magnitude higher.

⸜ DRIVERS The Crystal Cable speakers use two Scan-Speak drivers, already used in the Minissimo model. The highs are reproduced by a 25mm beryllium dome with a neodymium magnet and a solid aluminum alloy front, while the mids and lows are reproduced by a 15cm Revelator series driver with a laminated paper cone. It has been stiffened with a characteristic flower-shaped embossing. The manufacturer says it pairs them with a tolerance of 0.4 dB. The cabinet is ventilated with a bass-reflex located on the underside.

The internal connections were made with the company's Crystal Cable Infinite Crystal Silver, which is a monocrystalline silver cable, and the speaker terminals were purchased from WBT, a NextGen model. The Minissimo Forte are available in one of three finishes: champagne ("Champagne"), red ("Fire Glow Red") and black ("Matt Black").

▌ SOUND

˻ HOW WE LISTENED ˺ The Crystal Cable Minissimo Forte speakers were tested in a HIGH FIDELITY reference system. I used both the two-box amplifier I use every day, consisting of an Ayon Audio Spheris III tube preamplifier and a Soulution 710 solid-state power amplifier, and Leben CS-600X. They were connected to the Soulution 710 by Siltech Triple Crown cable, and to the Leben by Crystal Cable Art Series da Vinci. The sound source was an Ayon Audio S-10 II-T transport connected via three BNC cables to the converter section of an Ayon Audio CD-35 HF Edition SACD player. I used two two-and-a-half-meter Crystal Cable Ultra2 Diamond Power cables to power the speakers.

The speakers stood 230 cm from the listening spot and 230 cm from each other, counting from their vertical axis, slightly closer to each other than, Harbeth M40.1 that I use everyday. They were 90 cm from the rear wall, also from their axis and top edge. The speakers pointed directly to the listening position.

The distance between the speakers and their leveling were determined with the use of the Bosch PLR 50 C meter. More information on setting up speakers can be found in the article Mikrodostrajanie. Czyli ustawiamy głośniki (Eng. Micro-setting, i.e., we are setting up speakers), HIGH FIDELITY № 177, January 1st 2019, → HERE. More on HF listening room acoustics in Pomieszczenie odsłuchowe “High Fidelity” w oczach Mariusza Zielmachowicza (Eng. “High Fidelity listening room in the eyes of Mariusz Zielmachowicz”, HIGH FIDELITY № 189, January 1st 2020, → HERE.

⸜ RECORDINGS USED FOR THE TEST ⸜ a selection

⸜ ERIC REED TRO, Blue Monk, M&I Jazz MYCJ-30386, CD (2006).
⸜ TILL BRÖNNER & DIETER ILG, Nightfall, Masterworks/Tidal Master FLAC MQA Studio 24/96 (2018).
⸜ NAT 'KING' COLE, Love Songs, Master Tape Sound Lab | ABC Record AAD-245A, "Almost Analogue Digital" series, Master CD-R (2015); more → HERE.
⸜ AIR, The Virgin Suicide (Original Soundtrack), Virgin/Tidal, FLAC 16/44.1 (2000), reviewed → HERE.
⸜ ANJA GARBAREK Briefly Speaking, Virgin/EMI Music Norway 6080226, CCD (2005).
⸜ STEPHAN MICUS, Winter's End, ECM Records/Tidal, FLAC 16/44.1, reviewed → HERE.
⸜ GARY BURTON, CHICK COREA, Crystal Silence, ECM Records/Tidal, FLAC MQA Studio 24/96 (1973/?), reviewed → HERE.
⸜ ANTONIO CARLOS JOBIM, Stone Flower (CTI Records 40th Anniversary Edition), CTI Records/Tidal Master, FLAC MQA Studio 16/44.1 (1970/?).

The recordings used in the test can be found on the playlist HIGH FIDELITY: Crystal Cable Minissimo Forte , available on Tidal → HERE.

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WE TEND TO THINK OF STAND-MOUNT SPEAKERS as "monitors." It's a term taken from the "pro" world, where small, usually two-way, speakers are used to monitor sound during recording, mixing and mastering in recording studios in what is known as the "near field." This means that these loudspeakers lie on the mixing table or stand just behind it, or behind the desk on which the keyboard and computer display are located.

The near-field helps cancel out some of the room's acoustic response, because most of the sound comes to us directly, rather than through reflections from the walls, floor and ceiling - these are shifted enough in time that we hear them as echoes, rather than smeared sound. These small speakers are also designed to visualize to the sound engineer how a given musical material will sound through small radio and car speakers.

The name "monitor" implies ultra-precision and super-accuracy, but this is not the case, or at least not always. An exception was the BBC LS3/5a loudspeakers, which in many versions were used not only for sound evaluation in the BBC mobile studio, but also found a place in countless audio systems, often as the cheapest component of the system. And that's because, although small, they were true monitors. The Minissimo Forte go a step, or two, further.

Their sound is incredibly transparent, where they differ from the LS3/5a. The closest to them are the versions offered by Harbeth, but only to a certain level. This is because the Dutch speakers possessed a skill, allowing even better insight into the recording. But that's not all. As such they would be just another open-tone, bright sounding speakers. And they are not, because this "insight" of which I speak concerns not only the technical space of recordings, but also the emotional and even artistic space. Let me explain what I mean.

Listening to ERIC REED TRIO’S CD entitled Blue Monk I was able to appreciate its excellent production. Recorded in December 2005 at New York's Avatar Studios by Ted Henderson, the material was commissioned by Japanese label M&I Jazz, produced by Makoto Kimata and mastered in Japan by Kazuhiro Yamagata. Recordings of this type, especially contemporary ones, say from the 1980s onward, are wonderfully recorded, really well played, but they have something of an "order" about them.

I have the impression that American jazzmen treat them as an adventure, an opportunity to interact with musicians and/or producers from Japan, so they don't feel constrained by limitations, they are much more relaxed than when it is their "regular" album. So, on the one hand, we have the opportunity to listen to them as if they were playing an (unrecorded) concert, but also, on the other hand, it is never a masterpiece. Maybe I'm wrong, it's not a rule by the way, just my impression, but these types of albums are usually boring.

And why do I say this - high-end speakers show the first of these elements, technique, the best ones also convey the relaxed atmosphere of recordings. But they very rarely do what the Minissimo Forte does. These monitors momentarily showed everything I wrote about in the previous three paragraphs. To be clear - I listened to the Blue Monk album with great pleasure, it's a good performance. But also my thoughts on this type of recording, American-Japanese collaborations, took even clearer shape.

I can point to the reasons for this in the incredible resolution of the sound and its absolutely coloration-free tonality. At first the sound seems light, but only until, as at 3:02 of the Blue Rose track, Carl Allen plays a drum solo for a while. I could clearly hear a deep foot extension. But it's an ultra-fast descent, momentarily faded out, and thus easy to mistake for lightness. But already in A Thousand Kiss Deep, a cover of a song sung by Leonard Cohen on the Ten New Songs album, performed by the duo, the latter's double bass had fantastic timbre and clarity.

It is clear that the bass in Sleep from ANJA GARBAREK's splendid Briefly Speaking album was not as low as from my Harbeths. Even the LS3/5a in the Musical Fidelity version seemed to play it stronger. There, however, it was all about the coloration of the mid-bass breakthrough, which gave the sound volume. Here it was clean and clear, and the bass extended lower.

The most important thing, however, was that in almost every other case TILL BRÖNNER and DIETER ILG bass I'm talking about drowns out some of the sounds, covers them up, as if the speakers can't handle such high volume, making the midrange and treble lose clarity. The Crystal Cable speakers played the entire track with remarkable effortlessness and I heard so many things in the mix, so much going on there, that I found it hard to believe.

It can be said, and it comes easily to me, that the speakers from Elst play organically. It's a buzzword, often overused, but here it is most appropriate. And that's because I found no element in the sound of these designs that stands out from the rest. All the components here play in unison, so to speak. It is together creating something more than the individual components. For in addition to excellent timbre and detail, there is also an incredible soundstage. Wide and deep, with outstandingly presented layers.

When NAT 'KING' COLE sings "The very though of you" from the song of the same title it is not magnified, which is easy to do, but it is not withdrawn in the mix either. Although, when more reverb is superimposed on the vocals in the next one on Love Songs, which is a direct copy from the "master" tape to the Gold CD-R disc, we "see" it a little further away. But not so much that it was diminished and minimized. It still was a dense, warm vocal.

This is because the speakers are extremely skillful in showing what a given recording really is. Without embellishment and without "hitting" individual elements to the point where they "pop" out of the mix. Listening to Playground Love, the opening track of the AIR duo's soundtrack album for The Virgin Suicides, it's better heard than with many other speakers for the money that the vocals have been duplicated, perhaps even tripled, and then spread out in phase.

The same was true of the song Black Mother, from STEPHAN MICUS' amazing album Winter's End. Recorded entirely in the artist's island studio, using many instruments that are unusual for us, it has an incredible energy to it. And again - the test speakers wonderfully showed how many layers and tracks the chorus in this piece was composed of. But now something else caught my attention. Turning the volume knob of the Ayon Audio Spheris III preamplifier up and up, as if I were not going to stop, the sound stayed internally arranged, clear, and remarkably relaxed.

Normally it's the case that the louder you go, the less resolution and selectivity you get, as overdrive and cabinet problems start to come into play. The Minissimo Forte seemed not to notice that I was playing them so loud, they sounded perfectly, similar to when I listened to them quieter. I repeated this test with a completely different kind of music, namely theBrasil (Aka Aquarela do Brasil) by ANTONIO CARLOS JOBIMA.

The version available on Tidal is really very good. So the sound of the instruments was wonderful in its depth and undercurrent of warmth. However, when Jobim's vocals came in, I found that they were recorded much worse, with more narrowed bandwidth and strong compression. It was still a very satisfying reproduction, but I was waiting for the part where you can hear the instruments themselves, because it was amazing in energy and naturalness. More often than not, the speakers forgive this difference and show the leader's voice in a warm and close way, because that's how the whole thing sounds.

The thing that caught my attention just with this track was that the noise, quite a strong noise from the tape, was not emphasized by these speakers. I heard it, I knew it was there, but that's because I know the album so well. It was better heard in the Crystal Silence, from GARY BURTON and CHICK COREA'S album of the same title. The ECM label did not use Dolby noise reduction in its analog tape recordings, believing that it alters the sound in an unfavorable way.

But it made even more sense with it, because it turned out that I was listening very loudly, and I didn't realize it. Despite this high volume, Burton's vibraphone was not penetrating or bright. It had amazing layers of harmonics that made it seem deeper and denser than usual. Well, and those extra-musical details, the creaking of the chair under the pianist or under the vibraphonist, coming from other places, that is additionally selective, is a thing that is difficult to repeat, and is, after all, part of this recording.

▌ Summary

WRITING ABOUT PRODUCTS like Crystal Cable's Minissimo Forte is a pleasure. Although you need to know what to look for and what to compare them to, i.e. you need to have some experience to understand what you get with them, they will also enchant those who have nothing to do with audio and just want to listen to music.

These are not large speakers, so to get lower bass it is worth placing them close to the rear wall. They will play better with low-feedback amplifiers than with high-feedback amplifiers, perhaps even working in Class A. And they require high-end electronics and cabling. But that's because these are real monitors, not pretend monitors. If only they stood in good recording studios, we would have more well-recorded music.

Their sound is incredibly resolving and selective at the same time. And at the same time saturated, without "over-saturation", it's not that kind of playing. I heard no compression or coloration with them, no matter how loud I listened to them or what kind of music I played. They seem completely "absent" in the sense that it's hard to relate the sound to them, and the music comes from between them, from behind them and from the outer edges.

All this means that setting them up in small to medium sized rooms may be the best option that these rooms and their owners have ever encountered. That's why, after I finished the main part of my listening, I ran through all the playlists on Tidal I have, checking to see how a particular song with the Crystals sounded. I was genuinely curious to see how they would play, something that happens to me more and more rarely. The Dutch speakers refreshed something in me that had been somewhat dulled by years of working in the industry and that had become "professionalized" - sensitivity. And that's something no amount of money can buy. ●