AK's new earphone "AK ZERO1" will be released on November 12th. balance cable

As previously reported, the AK ZERO1 is Astell & Kern's first original IEM (in-ear monitor), a new start for the brand, and was developed with the aim of becoming a new standard for IEMs. This time, the release date has been officially decided, and product details such as driver specifications have also been released.

The biggest feature is the triple hybrid driver configuration with 3 different drivers. "Micro Rectangular Planar Dynamic Driver (PD: Planar Drive Driver)" and custom-designed dual balanced armature (BA) for high frequencies, "completely automated error-free process" Equipped with a manufactured 5.6mm dynamic driver for low frequencies (1PD + 2BA + 1DD / 4 drivers).

We harmonize these with crossover network management and pursue "extremely natural and accurate sound". Frequency response is 25-30kHz. Sensitivity is 96dB/mW, impedance is 16Ω, and THD (total harmonic distortion) is 0.7%.

The Micro Rectangular Planar Driver is an advanced driver specially developed to apply the planar drive (planar) driver design, which is said to be difficult to scale down in headphones, to IEMs.

Sturdy and light, square planar diaphragm is used to minimize frequency loss, and a composite diaphragm that combines a polymer film and a metal thin film provides "crystal-like clarity" like a BA driver. However, by driving with a coil shaped on a plane, it achieves a sense of realism like a dynamic type. Realized a "sound character that combines BA and dynamic type".

Although it is a planar type, it is said that by enclosing it in a metal body case similar to BA, it has given a degree of freedom in acoustic design that was difficult with the conventional planar type. By combining this with multi-networking, we have realized a design that draws out the potential of the planar type. The magnetic flux leakage of the powerful magnet that drives the diaphragm has been reduced, and the potential of the diaphragm has also been increased. Specifically, the magnetic flux density is increased to improve efficiency, and by confining the magnetic flux, it reduces the adverse effects on other drivers and contributes to higher sound quality.

Micro Rectangular Planar can be designed with the same architecture as BA. It is said that the sound quality can be adjusted in various ways. It was difficult with the conventional model due to its large size, but the miniaturization has made it possible to use the conventional development method, and the size reduction has made it possible to place it as close to the ear as possible even when making it multi-way.

In order to combine the sound of the three drivers into one, we designed a crossover network after understanding the parameters of each driver, realizing the ideal frequency characteristics that Astell&Kern seeks. Each driver is placed in an optimal position and housed in an acoustic chamber manufactured using 3D printing technology that is precisely controlled in micrometers.

Using our own advanced aluminum refining technology, we adopt a metal housing by CNC machining. It suppresses internal and external vibrations to achieve "focused and precise sound".

As a design that symbolizes the keyword "boundary to a new world" that expresses the sound of AK ZERO1, the housing is drawn with thick diagonal lines, and the shine of the cut surface emphasizes the premium feeling. Equipped with a uniquely shaped nozzle designed along the inner ear canal for a snug fit, it also has enough space to harmonize the three drivers.

In manufacturing, the company explains, "We have achieved the highest quality through a strict process, using handmade products by experienced Japanese engineers and excellent equipment."

Comes with a 120cm long 4-core pure silver-plated OFC cable for easy handling. Using high-purity silver plating, copper, and aluminum plugs, it was designed to transmit audio signals without loss. In addition, a high-precision MMCX connector is used to improve the connection quality with the cable. The input is an L-shaped 3.5mm 3-pole unbalanced.

In addition, 5 sizes of XS / S / M / L / XL silicone ear tips, 1 type (free size) urethane foam ear tips, carrying case, etc. are included.

AK PEP11 is a 4.4mm 5-pole balanced cable with an MMCX connector, and uses the same 4-core pure silver-plated OFC as the cable that comes with AK ZERO1. "Meeting the needs of demanding audiophiles who do not miss even the slightest changes in sound." We tested with several types of earphones and achieved excellent sound matching with various MMCX earphones. A Van Nuys cable pouch is included.