Astell&Kern x 64 Audio XIO | Hybrid Universal IEMs

Industry Leaders Astell&Kern and 64 Audio Join Forces to Present XIO, an IEM that Fuses Striking Design with Sonic Precision to Set a New Standard

• 10-Driver hybrid universal IEMs: (2x) DD + (8x) BA
• Features 64 Audio's patented tia, apex, and LID technology
• Faceplate representing Astell&Kern's design heritage
• Precision engineering for realistic depth and space
• Specially crafted Silver Copper cable

Astell&Kern x 64 Audio

XIO is the culmination of Astell&Kern and 64Audio’s shared philosophy on design and sound. Blending precision engineering with artistic sensibility, XIO goes beyond simply playing music. It shapes sound into a tangible experience, offering value that surpasses expectations.

Designed as a true object of art, XIO sets a new standard for high-end in-ear monitors—an uncompromising fusion of aesthetics and acoustics that redefines what's possible.

Engineered for Precision

XIO is meticulously engineered both inside and out. Its advanced hybrid system, featuring ten high-performance drivers, is finely tuned with a 4-way passive crossover to ensure every frequency is in perfect harmony. This precise tuning delivers a realistic sense of depth and a rich, spacious soundstage.

10-Driver System

tiaⓇ waveguide
The tia Ⓡ driver is designed with a direct-radiating structure that eliminates the traditional sound tube, enhancing the delicacy of high frequencies. This design minimizes damping and distortion, while the precisely positioned driver, together with a custom waveguide system, delivers a deep sense of space and airy, detailed highs.

BA Driver Manifold Assembly
The mid and upper-mid frequencies are powered by six and one balanced armature drivers, respectively, delivering smooth transitions and rich texture. Vocals, instruments, and their unique harmonic details are rendered warm and clear, creating a natural and well-balanced sense of space within the soundstage.

TRUE ISOBARIC Dual Dynamic Driver
The TRUE ISOBARIC structure features two dynamic drivers perfectly synchronized within an acoustically neutral coupling chamber, enabling precise control. This design delivers bass with exceptional depth and density, as well as powerful sound impact—surpassing what is typically possible with conventional IEMs.

64 Audio Patented Technology

tiaⓇ
Tubeless In-Ear Audio (tia) is a patented IEM design that minimizes resonance and distortion, delivering clear and vivid sound.

The tia system consists of the tia driver, single-bore design, and acoustic chamber. XIO adopts the tia driver and single-bore structure to capture the pure essence of sound.

apexⓇ
apex (Air Pressure Exchange) is a patented venting system that naturally releases pressure from the sealed ear canal while maintaining excellent noise isolation.
This technology reduces listening fatigue during extended sessions and provides a much wider, more realistic soundstage. The m15 module, standard with XIO, is specially redesigned for XIO with DLC coating on 904L stainless steel, making it a unique apex solution exclusive to this model.

LIDⓇ
Linear Impedance Design (LID) is a patented circuit that compensates for nonlinear resistance between drivers, ensuring consistent sound quality regardless of changes in the output impedance of the source device. This technology provides a stable sound signature and accurate frequency response at all times.

Precision-Milled 904L Stainless Steel Shell

The exterior of XIO goes beyond that of a typical IEM, standing out as an “audio art piece” that satisfies both visual and tactile senses.
Its robust structure is crafted by precisely machining 904L stainless steel—a material harder and more challenging to work with than standard stainless steel—and is then finished with a luxurious black DLC (Diamond-Like Carbon) coating for an exceptional premium texture.

The faceplate exhibits Astell&Kern’s design heritage, projecting a three-dimensional and elegant presence through deep shading and delicate reflections.

Silver Plated Copper Litz Cable

This dedicated cable, specially crafted for XIO, is designed to achieve perfect aesthetic harmony with the earbuds. The four-core cross-braided cable is made from silver-plated, single-crystal copper (UP-OCC), offering outstanding noise shielding and transparent signal transmission. With a low impedance of just 0.29Ω, it maximizes electrical efficiency.

Specifications

• Driver
  • (2x) Dynamic drivers for lows
  • (6x) BA for mids
  • (1x) BA for high-mids
  • (1x) tia BA for highs
• Frequency Response: 5Hz-22kHz
• SPL: 103dB @ 1kHz, 1mW
• Crossover: Integrated 4-way passive
• Impedance: 6.3 ohms @ 1kHz
• Cable: Silver-plated UP-PCC Copper litz
• Plug: 4.4mm
• Connector: 0.78mm 2-pin

In the Box

• Astell&Kern x 64 Audio XIO IEMs
• 64 Audio premium leather case
• TrueFidelity foam ear tips (SML)
• Silicone ear tips (SML)
• SpinFit Silicone ear tips (SML)
• Cleaning tool and cloth
• Cable clip
• Cable
• Apex modules
  • m20 (silver)
  • m15 (stainless steel)
  • m12 (gold)
  • mX (black)