c
In classic Astell & Kern fashion, the Zero1 comes packaged in a premium cardboard box with a glossy sleeve, proudly adorning high-resolution shots of the Zero1 IEM against a black backdrop. The technical specifications of the Zero1 can be conveniently found on the box, alongside the blown-up driver assembly dissecting the technologies condensed into the Zero1’s diminutive chassis.
Inside the box, you’ll find the ebony-coloured Zero1s and their attached MMXC cables seated in a felt-covered cardboard inlay. Underneath the top tray, you’ll see a premium clamshell-style leather case in black and a smattering of silicon and foam tips organised in ascending order according to their sizes (S, M, L).
The entire package, while straightforward, provides the bare essentials in a package that speaks to the brand’s prestigious background in luxury audio.
Design, Comfort, and Durability
The AK Zero1 has a distinctive trapezoidal form factor with an anodised steel frame. The bead-blasted/satin-finished grey faceplate has an interesting fold running diagonally through its centre, with Astell & Kern’s official logo laser-engraved into them. As far as design goes, the AK Zero1 bears striking resemblances to the “Glassmorphism” trend in web-design circles and the spartan appearance of brutalist buildings. As far as aesthetics go, Astell & Kern have not deviated in the slightest from its frontier-pushing, futuristic design language, with its ultra-modern exterior and cutting-edge engineering beneath it.
Each shell terminates in your standard MMCX, with “blue” and “red” circles indicating the L and R channels. To avoid confusion, there are two additional L and R indicators — one on each MMCX female connector (at the ends of each cable) and one faintly printed onto the nozzle side of each shell. Their nozzles are mid-length, with a wax guard protecting the three sound bores in each of them. The nozzles are adequately sized for my ears, with surprisingly deep insertion depth that surpassed preceding IEMs I’ve owned.
Throughout my outdoor usage, the Zero1 remained securely fastened to my ear canals, with outstanding ambient isolation from extraneous noise despite the pinhole-size vent on the nozzle side of each channel. However, the angular silhouette of the Zero1 presents one sticking issue. The sharp corner at the end of each channel presses against the walls of my outer ear. This unfortunate problem does detract from its wearability and long-term comfort.
Steel, while fantastic for its resilience to external wear and tear, is a denser and heavier material than aluminium — the go-to material for bespoke IEM manufacturers. For me, the Zero1’s weight did not detract from overall comfort levels, but I can foresee this being a potential problem for other listeners. But what you get in return is an over-engineered and robust IEM built without fault or error. The flawless finishing reflects the price premium attached to “Made in Japan” quality controls. Think pedantic in the best possible way.
Despite one or two ergonomic flaws, the Zero 1 epitomises luxury, precision and trendy design far surpassing the price it commands. From a pure fit and finish perspective, the Zero1 is within striking distance of build-quality kings, Campfire Audio. An exemplary showing for their first official IEM release.
Cable Quality
As mentioned, we are reviewing the Zero1 Black Special Edition with an OFC quad-braid pure silver-plated copper (SPC) cable terminated in a Pentaconn 4.4mm right-angled balanced connector. From first impressions, it has a non-descript but elegant appearance that doesn’t draw attention to itself — a visual complement to the Zero1’s austere design.
The included cables exhibit little-to-no memory retainment, making them more uncomplicated to coil and stow away without entangling them. The included cables are malleable and flexible, conforming to the contours of the outer ear, and free from pain or discomfort.
The burnished hardware at the Y-split and chin-slider and the terminations on either end each has concentric machining marks or treading for improved grip.
The default cable in the Special Edition of the Zero1 is excellent to use and quite frankly, difficult to critique. The only gripe I could find is the lack of an included 4.4mm balanced female to 3.5mm unbalanced male adapter — an option that would have made the Zero1 an ultra-versatile option for all listening intents and purposes.
Onto the next page for details on sound…
