SUPRA CLASSIC 2.5H Speaker Cable — A Listening Report

This time I thought I’d write about the speaker cable I somewhat impulsively bought the other day — the SUPRA CLASSIC 2.5H. SUPRA is a consumer audio brand by Swedish cable manufacturer JENVING, distributed in Japan by Saec. They’re rather obscure here in Japan, but apparently they’re a major brand boasting the largest production volume of audiovisual cables in Europe.

Among SUPRA’s speaker cable lineup, the SUPRA SWORD — a high-end speaker cable backed by a distinctive patented theory — caused quite a stir some time ago with its reputation for a new dimension of sound quality. I tried the CLASSIC 2.5H, which is the entry-level model sold in Japan, with the fairly light hope that perhaps some essence of the SWORD might be felt even here.

The polyethylene jacket of the CLASSIC 2.5H is a vibration-damping, flame-retardant, halogen-free material — light blue in colour with a pleasantly soft feel. In appearance it’s nothing out of the ordinary: a perfectly common thin parallel-type speaker cable. The conductors are a 2.5mm² twisted construction of 320 strands of ultra-fine 5N high-purity copper wire (OFC oxygen-free copper). Tin-plated conductors in a pure Hi-Fi speaker cable are perhaps a little unusual these days.

The CLASSIC 2.5H has a sibling in the CLASSIC 1.6, which shares the same construction but with fewer conductors, and two models above it — the CLASSIC 4.0 and CLASSIC 6.0 — with more conductors.

I connected the CLASSIC 2.5H to Sub-System A. The speakers are the AUDIOPRO Image11 — Swedish, like SUPRA. The amplifier is the ONKYO A-1VL, and the CD player is the CREEK Evolution CD. The first thing I noticed when sound came through the CLASSIC 2.5H was its richness of reverberation — the resonance drifts and lingers in a most generous way. I have a preference for a live, hall-tone-rich sound, so this was quite a pleasing impression. It has a fast transient response with well-defined outlines — a distinctly Hi-Fi character. The surface of the sound image carries that slight bloom particular to multi-strand conductors, and combined with the abundance of reverb, it has a sensitive, almost electrostatic-speaker-like quality about it. The high frequencies are therefore vivid and attractive, but on the other hand the low-frequency weight is rather restrained. Perhaps that is simply the nature of the most affordable model with the thinnest conductors…

Because the upper musical range is quite sharp, there is a possibility that extended listening may become slightly fatiguing. The very top end and the rendering of background detail are quiet, with a fairly ordinary level of information retrieval. At first listen the surface clarity is high and it comes across as Hi-Fi and high-resolution, but the more you listen into it, the impression grows that it doesn’t quite extend to information retrieval in the deeper sense. Not merely because it’s also Swedish, but the CLASSIC 2.5H shares a similar sonic character with the Audiopro Image11 — as though an additional layer of colour has been applied on top. It’s a very different matter from the Audiopro ALLROOM SAT, though…

The sense of energy is modest and the overall tendency is reserved. The sound image is slender, delicate, and refined — so I think it genuinely suits classical music, and early music or chamber music in particular. The musical nuance is rich and the musicality is high. Cables of this delicate, high-resolution type tend more often than not to produce a sound that is expressionless and lifeless, but the CLASSIC 2.5H overflows with a distinctive, dignified nuance that seems to draw one towards the pianissimo end of things, which I find quite appealing. That said, the lack of physical weight and energy means it is not well suited to bright, bouncy, exuberant expression — it has a faintly melancholy, wistful quality about it. The resonance is clear and transparent, and at first hearing it comes across as vivid and cool, but the more you listen, the more you sense a certain inner warmth within the sound itself — and it may be precisely this looseness of detail that marks the difference from a more expensive cable. The conductors are tin-plated, but I did not detect any character I would attribute to the plating. The tonal colouration falls within the territory of OFC twisted-copper wire — as if listening through a pair of sunglasses — which is quite different from the fresh, crisp character one might imagine from the tin plating or the pale blue jacket.

Newly released stereo mini plug to RCA conversion cable: SUPRA BILINE-MP. A sophisticated cable that converts the output of iPods and other portable music players into a delicate European sound.

If the tonal character of the CLASSIC 2.5H were taken as a base, with the frequency range extending smoothly downward, a moderate sense of energy added, and information retrieval increased considerably — well, the SUPRA SWORD, which enjoys such a high reputation for extraordinary sound quality, is something I’d like to try at least once. As for the entry-level CLASSIC 2.5H tested here: it sounds impressive on first listen, but there is an undeniable lack of vitality, and the sharp rise of the delicate mid-to-high frequencies can at times become a little noticeable — so despite the initial “oh, that’s rather good” pull, after a few hours of listening I found myself growing weary of it. The bloom inherent to twisted-wire construction does contribute to the cable’s delicate charm, but it might be worth crimping on SUPRA’s own Y-lug or banana plug terminations to tighten up the contact points and add a touch more smoothness to the surface of the sound… though only if crimp-type rather than screw-type terminations are available.

The SUPRA EFF-IRB RCA cable is also a long-time favourite that I have been using for many years.

The CLASSIC 2.5H’s richly reverberant sense of spaciousness is genuinely impressive, so I think it works rather well for enhancing the surround effect of small surround speakers. Or, in the case of a small speaker that doesn’t have the same level of resolution as the Image11 to begin with, it might sharpen things up considerably and give a strong sense of Hi-Fi. Had I chosen the CLASSIC 4.0 or CLASSIC 6.0 with their heavier conductors, the bass would likely have been more substantial and the overall balance improved. Even so, there is an undeniable appeal to that nuance-rich, delicately drifting tonal character — and assuming that quality is retained and further refined in the step-up models, I’ve been idly thinking it might be rather nice to use the mid-range SUPRA LINC 4.0 to build a DIY mains cable for my CD player.

Further impressions of the SUPRA CLASSIC 2.5H can also be found in this article

Founded in 1976, JENVING specialises exclusively in AV cable production, boasting the largest production volume in Europe and receiving the highest acclaim in world markets for its quality. The first introduction to Japan came in 1995 with the SUPRA PLY speaker cable, which at the time attracted considerable attention by clearly presenting a theoretical basis for high sound quality in speaker cables — a theory centred on the challenge of how cable construction should address inductance. Since then, JENVING has continued to introduce new products one after another with ideas that overturn conventional wisdom, and the launch in 2002 of a completely new concept in speaker cables — the SUPRA SWORD — as a world-patented product, is still fresh in many memories. The CLASSIC series represents the ultimate speaker cable capable of demonstrating in practice the theoretical correctness that has been developed to this point. The conductor bundles of up to 756 individual tin-plated high-purity copper strands (320 in the 2.5H) exhibit high resistivity at the insulation level, while the semi-insulating jacket structure minimises leakage current between strands, successfully suppressing the rise in impedance at high frequencies. The result is a dramatic reduction in transmission loss, and by eliminating phase deviation between fundamental tones and their harmonics, the cable achieves a well-balanced, wide-band dynamic range with considerable headroom — and this is its defining characteristic.