Inakustik Referenz NF-404 Micro AIR Interconnect Cable Review: The Art of Losing Nothing

Welcome to our Inakustik Referenz NF-404 Micro AIR Interconnect Cable Review. This is a cable built on a refreshingly honest idea. Interconnects are often sold on how much they will “improve” your system. in-akustik takes a more disciplined view. The best cable, they argue, is the one that loses the least of the original signal. Here at The Audio Tailor we have a deep appreciation for that philosophy. After digging into the engineering behind the NF-404 Micro AIR, we think it is one of the most intelligently designed interconnects in its class. Here is why.

The Philosophy: Cables Should Just Stay Out of the Way

“Cables can't work miracles. The best cable isn't the one that squeezes the most out of your hi-fi setup, but the one that loses the least of the original sound. Cables should just sound natural and stay out of the way.”

— Holger Wachsmann, Product Developer, in-akustik

On the surface, that sounds modest. In practice it is a demanding brief. A truly transparent interconnect has to defeat three enemies without adding any character of its own:

• Capacitance
• Signal noise
• Electromagnetic interference

The NF-404 Micro AIR tackles each one with a dedicated engineering solution. Every cable is hand-made in in-akustik's own factory in Germany. The goal is an open, precise and detailed presentation. That comes not from added sparkle or warmth, but from removing the obstacles between the recording and your ears.

Understanding the Enemy: Capacitance and the Low-Pass Filter Effect

Line-level RCA and XLR outputs carry very weak signals. Those signals are acutely sensitive to a cable's electrical properties, and capacitance matters most of all.

Every cable's dielectric stores electrical energy and releases it with a slight time delay. In effect it behaves like a tiny battery. It soaks up part of the audio signal and discharges it a fraction late. in-akustik offers a lovely analogy here. Think of the crackle when you pull off a synthetic jumper. That is energy stored in the plastic being discharged. The same thing happens, on a smaller scale, inside the insulation of an audio cable.

The audible consequences are real. High capacitance acts as a low-pass filter. It attenuates high frequencies, introduces phase shifts and blunts transient precision across the whole spectrum. A high-capacitance cable can leave a system sounding slightly rolled-off, slightly smeared and a little less alive than the recording really is.

The ideal dielectric would store no energy at all. That material is air.

Micro AIR Technology: Air as the Dielectric

You can't switch off the laws of physics, but you can use them cleverly. in-akustik's Micro AIR technology uses a complex, diamond-shaped insulation structure. This precision geometry forms tiny air chambers between the conductors, and it does three things:

• It increases the distance between conductors.
• It raises the proportion of air in the insulation.
• It dramatically reduces capacitance compared with any solid dielectric.

Lower capacitance means far less of that low-pass filtering. High frequencies keep their integrity, phase relationships stay accurate and transients stay sharp. Those are the cues your brain relies on to hear texture, attack and space.

The NF-404 Micro AIR follows directly from in-akustik's acclaimed Referenz AIR Helix cables. It applies the same air-dielectric principles in a more compact and versatile form. It suits an entry-level audiophile system just as well as a full reference installation.

Guided Copper: A Defined Architecture for a Defined Signal

Conventional conductors bundle their individual strands loosely. Where those strands touch each other unpredictably, micro-distortions occur. Those random contact points generate signal noise, and you hear it in three ways:

• Harshness in sibilants, such as the “S” sounds in vocals
• A veiling of fine high-frequency detail
• Weaker spatial imaging

in-akustik's Guided Copper construction is designed to eliminate this. Each conductor is built around a central PE wire, with the OFC copper strands arranged around it in a precisely defined geometry. Additional PE wires separate and insulate each copper strand from its neighbours. Every contact point is controlled and every wire sits in its designated position.

The result is a stable, uniform signal path with interference and noise significantly reduced. That preserves the fine details, clarity and timing behind convincing imaging and transparency. The conductors themselves are high-purity Oxygen-Free Copper (OFC), chosen for excellent conductivity and signal fidelity.

Symmetrical Architecture and Double Mono: Built for the Real World

Modern listening rooms are full of electromagnetic noise. Switching power supplies, Wi-Fi routers, mobile networks and smart devices all add to the electrical smog. The NF-404 Micro AIR uses a symmetrical signal architecture and Double Mono technology in both its RCA and XLR versions. Stray signals that get into the cable are effectively cancelled by the balanced layout, so transmission stays stable and low in interference.

Shielding is tailored to each termination:

• RCA: a floating shield
• XLR: a 2-fold braid plus foil shield

This matters because few of us listen in a lab. Your system might share a cabinet with a streamer, a router and a TV. Your amplifier rack might sit next to a power board full of chargers. In either case, the NF-404 Micro AIR is engineered to keep the background quiet.

Connectors and Build: German Engineering at Every Junction

A cable is only as good as its terminations, and in-akustik has not cut corners here:

• Tellurium copper contacts with rhodium coating for a durable, high-integrity connection
• Pressure-grouted connector assembly at 1.5 tonnes for a firm, permanent bond between conductor and contact
• Solid metal connector housings
• An 8.5mm cable diameter with a PE network jacket

Every NF-404 Micro AIR is made by hand in in-akustik's own German factory. Each cable goes through functional testing, mechanical testing and live performance verification before it leaves the building. This is not an outsourced product. It reflects a manufacturing culture built on a love of music and a passion for precision.

Sonic Character: Open, Precise, Uncoloured

in-akustik describes the NF-404 Micro AIR's sound as open, precise and detailed, with a natural, uncoloured character. That follows directly from the engineering:

• Low capacitance means treble isn't softened and transients aren't blurred.
• Controlled conductor geometry means sibilants stay clean rather than spitty.
• Strong EMI rejection means a darker, quieter background for low-level detail to emerge from.

What you should not expect is a tonal “flavour”. This cable isn't designed to warm up a lean system or add sparkle to a dull one. It is designed to let your components sound like themselves. For listeners who have carefully chosen their source, preamp and power amp, that is exactly the point. If you are unsure whether neutrality or a voiced cable best suits your system, our team is always happy to talk it through on 1300 308 711.

Who Is the NF-404 Micro AIR For?

• The system builder who values transparency. You have invested in your components and want to hear them without a cable editorialising.
• Balanced-system owners. The XLR version, with its 2-fold braid and foil shielding, suits fully balanced DAC, preamp and power amp chains.
• Vinyl and streaming enthusiasts alike. Weak line-level signals benefit from low capacitance, whether they come from a phono stage or a network player.
• Real-world rooms. Anyone whose hi-fi shares space with Wi-Fi, switch-mode supplies and other EMI sources.
• Those building a matched loom. The NF-404 pairs naturally with in-akustik's LS-404 Micro AIR speaker cable for a consistent system-wide approach.

Lengths of 0.75m, 1m, 1.5m and 2m cover most interconnect runs, and custom lengths are available on request. If your rack layout calls for something unusual, drop us a line at sales@theaudiotailor.com.au and we'll help you sort the right configuration.

Key Specifications at a Glance

Specification	NF-404 Micro AIR RCA	NF-404 Micro AIR XLR
Connector	2 × RCA → 2 × RCA	2 × XLR (f) → 2 × XLR (m)
Technology	Micro AIR, Double Mono	Micro AIR, Double Mono
Design	Symmetrical	Symmetrical
Conductor Design	Guided Copper	Guided Copper
Conductor Material	High-purity OFC copper	High-purity OFC copper
Dielectric	Air chambers	Air chambers
Shielding	Floating shield	2-fold — braid + foil
Jacket	PE network jacket	PE network jacket
Cable Diameter	8.5mm	8.5mm
Connector Assembly	Pressure-grouted contacts (1.5 tonnes)	Pressure-grouted contacts (1.5 tonnes)
Connector Housing	Solid metal	Solid metal
Contact Material	Tellurium copper, rhodium-coated	Tellurium copper, rhodium-coated
Available Lengths	0.75m, 1m, 1.5m, 2m	0.75m, 1m, 1.5m, 2m
Customised Assembly	On request	On request
Conformity	CE, REACH, RoHS	CE, REACH, RoHS
Made in Germany	Yes	Yes

Pros and Cons

Pros

• Micro AIR air-dielectric design dramatically reduces capacitance, preserving treble, phase accuracy and transient speed.
• Guided Copper geometry controls every strand contact point, minimising micro-distortion and sibilant harshness.
• High-purity OFC conductors for excellent conductivity.
• Symmetrical, Double Mono architecture delivers strong EMI immunity in real-world rooms.
• Tailored shielding: floating shield on the RCA, 2-fold braid and foil on the XLR.
• Premium rhodium-coated tellurium copper contacts with 1.5-tonne pressure-grouted assembly.
• Hand-made, tested and verified in in-akustik's own German factory.
• Available in RCA and XLR, four standard lengths, plus custom lengths on request.
• Natural, uncoloured voicing lets your components shine as intended.
• Pairs with the LS-404 Micro AIR speaker cable for a cohesive system loom.

Cons

• Its honesty cuts both ways. It won't mask shortcomings elsewhere in your system, but it will reveal just how good your best components are.
• Once you hear what low capacitance does for your system, you may want the matching LS-404 speaker cable too.

The Verdict: Transparency Engineered, Not Promised

Plenty of cables make big claims. The Inakustik Referenz NF-404 Micro AIR Interconnect Cable instead makes a sensible promise and backs it with tangible engineering. Air-chamber insulation tames capacitance. Guided Copper geometry tames conductor noise. A symmetrical, Double Mono layout with appropriate shielding tames EMI. Premium tellurium copper and rhodium terminations, hand-assembled and tested in Germany, finish the job properly.

The result is an interconnect that does exactly what Holger Wachsmann says a cable should do. It stays out of the way and lets the music through. Whether you are refining an entry-level audiophile system or completing a reference rig, the NF-404 Micro AIR deserves a place on your shortlist.

Want help choosing between RCA and XLR, working out the right length or planning a matched in-akustik loom? Our team of Stuart, Gabby, Nathan and Vaughan would love to help. Call us on 1300 308 711, email sales@theaudiotailor.com.au, or visit the NF-404 Micro AIR product page. We ship Australia-wide.