Inakustik NF-4005 Air interconnect & LS-4005 Air speaker cables
Even hard nosed industry lags that have seen everything were taken aback by the sheer girth of Inakustik’s cables when they saw them in the system, the NF-4005 Air interconnect appears to be almost as wide as it is long such is its hawser like bulk. Both this and the matching LS-4005 Air are 40mm in diameter, so nowhere near the one metre length of the XLR terminated interconnect, but they are the nearest thing to an anaconda that I have had in the system, ever.
The size is a result of the construction, the images show this very clearly, a series of discs are used to space the conductors within the cable so that air can be used as a dielectric instead of a more conventional insulator. Most cables have lacquer, plastic or sometimes natural materials between the conductors to keep them apart but any material that is in such close proximity will affects its sound. Most will agree that air is the ultimate insulator, it allows the conductors to carry the signal with the minimum of impact on sound quality. Finding a way to keep the conductors separate in a cable construction that can withstand the rigours of twisting, bending etc has always been the challenge.
Inakustik is based in Ballrechten-Dottingen in the south west of Germany and has been making cables since 1977, the company started its own record label in 1986 and sells a range of titles on vinyl and reel to reel tape. Both the NF-4005 Air interconnect and LS-4005 Air speaker cables are based around the same low loss air dielectric technique and their conductors are arranged in a helical topology in order to maximise space between the various strands. These are made of high purity OFC copper that is carefully selected prior to being drawn into strands, Inakustik’s top cables employ silver but the 4005 Air models are close to the best copper models they make.
The difference between the NF-4005 Air interconnect and LS-4005 Air speaker cables is in the quantity and nature of the conductors, the interconnect has two (three in the balanced) whose strands are woven around a tube to form a helical weave, and each conductor is spaced well apart from the others. In the LS-4005 Air speaker cable 15 conductors form a denser and slightly different weave around a tube with a central core.
The speaker cable can be terminated in bi- or single wire connectors using Inakustik’s flexible ball-head plugs or spades. This is quite a clever system for avoiding stress in the cable at the point where it’s connected to amp and speaker, a situation which varies a lot but usually results in the cable having to bend to accommodate the connection. The ball-joint allows you to connect the plug or spade and then have the cable itself at whatever angle works best.
A hex key in the box is for tightening up this ball-joint once the best position has been established, a process that ensures a good connection between cable and connector. Inakustik use tellurium plated copper connectors because the plating is much more durable and consistent than gold and copper is a much better conductor than brass, can’t argue with that.
Both 4005 Air cables are terminated without solder using high pressure crimping, 1.5 tonnes apparently, this ensures a reliable and stable connection with the minimum of transition resistance. .This is something that occurs with every connection in a signal path as you are probably aware. The NF-4005 Air interconnect supplied for review was terminated in XLR plugs but both this and the RCA alternative have point to point connections; that is the conductor continues all the way from one plug to the other without the use of tails to provide flexibility. Despite their bulk the Inakustik cables are surprisingly soft and flexible which makes it easy to hook up a system and stops anything sticking out at inconvenient angles.
Sound quality
I started with the LS-4005 Air speaker cable between the Moor Amps Angel 6 power amp and PMC prophecy9 speakers and got a result that was rather good, the sound having a very precise wave shape which sculpted imaging with considerable precision. Tonally this is a warm and rich sounding cable, probably very close to neutral and not at all Germanic in the old fashioned sense of bright, tight and forensically clean. It does sound clean but without any tonal leanness, rather you get a good old iron fist in a velvet glove presentation that delivers power with smooth leading edges that allows well recorded vocals a rare degree of purity.
This is clearly a low noise cable as well, with less less hash or blurring of detail than most. Something it achieves without any sharpness or leanness of tone, in fact it avoids any sense of grain altogether, the mids and highs being smooth clean and transparent. Adding the NF-4005 Air interconnect to the mix enhanced image projection still further and brought out extra detail which made the sounds seem more like they were in the room, the sense of presence being clearly greater.
Equally appealing is the way that the sound seems to escape the speakers more effectively, something that these PMCs are particularly good at in the first place. There is also a glow to the sound, a slight aura that makes it seem more vivid and real and is probably something that was done in the studio to make the remastered recording of Bob Marley’s No More Trouble sound better. I should mention that the timing is also very good, all too often refined cables like this emphasise detail at the expense of rhythm but that is clearly not the case here, this track grooved like a mother.
With the much more recent song Birds by Dominique Fils-Aimé, I heard a much richer, more rounded and clear rendition than I am used to, it’s as if the 4005 Air cables allow more of the colour in the recording to get to the speakers. It’s important to remember that all any cable can do is transmit signal with the minimum of loss and distortion, cables should not add to the signal nor corrupt it in any way but that is clearly a big challenge as anyone that’s compared them will know.
Inakustik seem to appreciate this and have developed cables that do very little harm and allow an awful lot of signal through without apparently altering it. They manage to deliver a huge amount of coherent musical detail which makes the end result extremely engaging and real sounding. I particularly enjoyed what they did in the voice and percussion on Birds.
Bass is also well served and not short of body or texture, the track Queen Mary by Francine Thirteen is a good test of low frequencies but can sound overly heavy on many systems which discourages level. Here there is a sense of clean control that makes it much easier on the ear, still powerful but not overblown. Much of the 4005 Air cable’s appeal comes down to the very low noise floor it achieves, this is something that is critical to the sense of ease it delivers.
A noise floor is not something that is obvious until it changes, you don’t think that a cable or component sounds hard or muddied but when the noise floor drops the sound becomes more relaxed and it’s possible to hear more detail. It’s as if your brain doesn’t have to work so hard to enjoy the interplay of the musicians and the subtle cues that help make their efforts coherent.
On Achirana by Arild Andersen (a truly beautiful ECM release from 2000) this means real tonal shine from the piano, impressively solid high frequencies and enough dynamic range to allow the recording to expand in the room. Which makes for highly compelling listening with all manner of music from Floating Points’ electronica to Keith Jarrett’s solo piano.
I rarely find speaker cables that I can tolerate let alone enjoy but the 4005 Air combination is very easy to enjoy indeed. I tried it with the Axxess Forté 3 amplifier reviewed recently and got some equally enthralling results, not least in the huge depth and solidity of image that the LS-4005 Air speaker cables allowed it to deliver. There were so many layers in some tracks that listening became a voyage of discovery, who knew that there was so much going on. The depth of tone revealed was particularly attractive, and contributed to the handclaps on Birds sounding more real and present than I had previously encountered.
Conclusion
Inakustik clearly go to great lengths with the 4005 Air cables and this pays off with a richness and depth of sound that makes the asking price seem reasonable. These are not off the reel cables, this company hasn’t specced a topology and had it manufactured by a large cable company, they build them by hand