In-akustik NF-2405 and LS-2405 Air Pure Silver interconnect and speaker cables
Cables are and always will be a controversial subject in the audiophile community. They are the first thing that detractors point at and call snake oil, yet enough open eared enthusiasts have heard the differences they make to encourage cable makers to aim for the stars. It’s true that virtually any cable will carry an audio signal just as it’s true that any car will get you from A to B if it’s not broken, but you can easily imagine that you will arrive in a more relaxed state if you travel in air suspended ease than on the hard suspension of small car. In the case of cables what you want is the minimum of loss. A cable that delivers more information without adding to or distorting it will produce a more accurate result than one that adds its own characteristics or simply fails to deliver the complete signal.
Achieving a lossless cable that doesn’t place its own signature on the sound is surprisingly hard. If it were easy then we would all have perfect cables and the market would be relatively quiet. As it is there are numerous cable brands using all manner of techniques to achieve this apparently simple aim. How to differentiate them is tricky but most agree on a few things, among these are that air is a fabulous dielectric or insulator, it has less discernible character than almost any alternative. Another is that all other things being equal silver is a better conductor than copper; it certainly measures that way and a great many cable makers use silver in their best models.
That is certainly the case at German company In-akustik who make a wide range of cables with prices ranging from the beer budget to the cor blimey – as you might imagine the 2405 Air Pure Silver cables are from the latter end of that scale. The NF-2405 Air Pure Silver interconnects are the best they make but the matching LS-2405 speaker cables are a couple of rungs down from the apex of the Referenz range but still distinctly spendy and the most expensive I have reviewed.
Should you spend more on cables than you would on components? Not in total perhaps but these and other high-end cables make a good case for spending a high percentage of the overall system cost this way. Perceived value is usually a problem with cables but you can see from the material used and the complex way in which these cables are constructed that they go some way to offset this criticism. There are certainly more straightforward cables on the market that cost as much.
In-akustik’s thing is air dielectric. They use perforated discs to spread the conductors in a helical array along the cable. In the LS-2405 speaker cable there are four 1.2mm square conductors for the positive signal and the same amount for the return. The actual wire strands have a lacquer dielectric and these are wound around a supporting core to form a mesh tube. This is a complex cable to build and not something you can buy off the reel from an industrial cable company.
The NF-2405 interconnect uses a similar approach but doesn’t require as much silver as is used in the speaker cable. In the XLR terminated version there are three conductors for a balanced connection with shielding around the outside of the discs that spread them apart. This makes the cable larger than most interconnects with a 25mm diameter, but it’s not stiff and the tails for each plug make the ends more flexible. I had expected the XLR plugs to have silver pins but they are tellurium copper, presumably because pure silver tarnishes when exposed to air. Like the LS-2405 the strands inside the cable are lacquered to avoid this.
Both cables have In-akustik’s own plugs. The NF-2405’s XLRs are rhodium coated and can be rotated by plus or minus 45 degrees. The cable is flexible but doesn’t like twisting so this is a useful feature. The LS-2405 comes with both 4mm banana plugs and spade connectors which fit to a universal ball joint that allows them to be moved to the most practical angle and then fixed in place with the supplied hex key. In situations where the cable is hanging off the back of an amp or speaker, this flexibility is very convenient.
Sound quality
I was supplied with a one metre pair of balanced NF-2405 interconnects and a three metre set of LS-2405 speaker cables. I started out using the interconnects between a Bricasti M11 Classic DAC and my Moor Amps Angel 6 power amplifier; the DAC has a decent onboard volume control so there’s no need for preamp in the chain. It took the place of an Atlas Ailsa Duo cable which is less than half the price so I was expecting a quality lift, and I wasn’t disappointed. The NF-2405 has both phenomenal clarity and real power in the bass allied to superb definition – the life force in the music doubled in intensity via this In-akustik interconnect.
It makes most cables seem dynamically restrained, in fact, the way it adds to the drive and impact of the music is genuinely thrilling. When you play a great recording like Birds (Dominique Fils-Aimé) the solidity and presence of the voice is spellbinding. The way that the NF-2405 both opens up the soundstage yet gives it more three-dimensionalsolidity is pretty damn spectacular. It really brings out the clean snap of the beat and the burr off the double bass on this. Another familiar track revealed that the In-akustik exposes oodles of fine detail, making the nature of quiet sounds much easier to identify, in this instance a softly brushed snare.
On Keith Jarrett’s rendition of Everything I Love I was struck by the way that the complex playing at the start of the track was that much easier to follow, there seems to be more space between the hands and the notes such that what he’s playing is easier to comprehend. This interconnect appears not to blur the attack and decay of the notes but resolves precisely what’s going on without apparent tonal or temporal colouration.
Adding the LS-2405 between power amp and PMC prophecy9 speakers also has the effect of opening up the sonic picture: high frequencies being particularly well resolved and bass coming through very strong indeed. This presentation made Jarrett’s vocalising slightly more obvious and brought out the sizzle in the cymbals. There is an abundance of detail across the board and this brought expression to Cleo Reed’s voice as well as power in the bass line on her Salt n’ Lime track, all this accompanied by the slight hardness that compressed productions designed for the pop market often exhibit, not too bad though in this case. This In-akustik cable is very revealing and very fast, dense material is not robbed of its complexity but it’s a lot easier to appreciate what’s going on. The rapid-fire vocals of In My House were particularly pleasing, I hadn’t realised that Kendra Morris enunciates the lyrics so precisely despite having played this track many times in recent months.
It occurred to me that using cables that cost significantly more than the loudspeakers in the system might not be the best way to understand what the cables do, so for context I wheeled in the Dali Epikore 9s. These have a more relaxed balance than the PMCs but are very capable indeed with bass extension to die for; they brought out the shape, power and depth that the 2405 cables were delivering and revelled in the huge quantities of detail coming down the helical conductors. This brought out the drum and bass lines on In My House a treat, the latter being particularly dextrous and entertaining and easy to follow thanks to the In-akustik’s ability to avoid any fudging of the transitions where each note stops and starts.
The Velvet Underground’s Rock & Roll is not the sweetest recording around and that much is apparent in the brash sound, but that doesn’t get in the way of it being a great song when delivered via cables as capable as the 2405 Air pairing, in fact the groove was irresistible and it’s easy hear why this band almost single-handedly launched the British indie scene that came a decade later.
I picked out Philip Glass’s Koyaanisqatsi as you do and revelled in the remarkably calm and low organ notes that the 2405s helped the Dalis to resolve. Silver cables have inclined to a light, bright balance in my experience but that is clearly not the case with the In-akustiks, here the bass warrants inclusion in the thus far imaginary Now That’s What I Call Low End compilation that a major label should have the sense to release!
I also tried the NF-2405 between preamp and power amp while using my turntable and phono stage. Here it replaced Atlas Arran Ultra Grun RCA cables which again are not in the same price league as the silver In-akustiks but pretty decent cables. This time the upgrade was more marked with the silver interconnect delivering an immensely quiet, calm and dark background for the music, allowing all four dimensions to be expressed precisely yet in an incredibly natural fashion. This source always sounds better than the digital but here the gulf between the two expanded significantly. I have played Herbie Hancock and Norah Jones’s version of Court and Spark an awful lot but rarely has it sounded so good. The piano at the end was mesmerising, Hancock is better than most of us realise.
I then decided to try the vinyl version of Koyaanisqatsi just for a bit of low-end fun. It turned out to be nothing short of jaw dropping: the power and nuance of the piece was off the scale and I have to admit it brought a tear to my eye. I have always liked this title track but don’t think that it has ever had the emotional impact that it did via the In-akustik 2405 Air Pure Silver cables.
Conclusion
These are obviously extremely expensive cables but in the context of an expensive system, and there are plenty of them out there, they are not excessive and have plenty of competition. The 2405 cables with their air dielectric and silver conductors prove that what In-akustik is doing works. It delivers a signal that appears uncoloured and replete with detail whilst being uncannily coherent.
I have been resistant to silver as a conductor largely because early experiences were of massive transparency but limited bass performance, the NF-2405 and partnering LS-2405 Air Pure silver cables have reframed my opinion and I will be looking out for the material at every opportunity from now on.