64 Audio x Astell&Kern
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.
Designed as a singular object, XIO sets a new standard for high-end in-ear monitors through its
uncompromising approach to both aesthetics and acoustics.


64 Audio has established itself as an innovative company that pushes the boundaries of IEMs, thanks
to a team of top professionals and proprietary patented technologies.
“XIO boldly opens a new chapter in the evolution of high-end in-ear monitors.
It goes beyond simply reproducing sound—it embodies our philosophy of sculpting sound itself. By
combining mechanical perfection with musical sensibility, XIO creates value that exceeds
expectations.”

Internal Structure

- 01. tiaⓇ Waveguide
- 02. 0.78mm 2pin Socket
- 03. Diamond-Like Carbon (DLC) Coated 904L Stainless Steel
- 04. Mid Frequency BA Driver
- 05. TRUE ISOBARIC Dual Dynamic Driver
- 06. Diamond-Like Carbon (DLC) Coated 904L Stainless Steel
- 07. Apex Module
- 08. High-Mid Frequency BA Driver
- 09. Driver Housing
- 10. tiaⓇ High Frequency Driver
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-Drivers Hybrid System
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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.
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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.
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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.
Patented Technology
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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 (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. -
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.
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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 UP-OCC 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.
Handcrafted IEM Made in the USA
64 Audio uses carefully selected components sourced from trusted partners around the world. Every step of design, assembly, and quality control is meticulously carried out by skilled engineers in the United States.
Components
· XIO Universal In-Ear Monitors
· 64 Audio Premium Leather Case
· TrueFidelity Foam Ear Tips (S,M,L)
· SpinFit Silicone Ear Tips (S,M,L)
· Silicone Ear Tips (S,M,L)
· Cleaning Tool
· Cleaning Cloth
· Cable Clip
· 4.4mm Silver Plated UP-OCC Copper Litz Cable
· Apex Modules: m20 (Silver)
Special m15 (904L Stainless steel with DLC Coating)
m12 (Gold), mX (Black)

Specification
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General Specifications
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Model
XIO
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Driver
2 Low DD – 6 Mid BA – 1 High-Mid BA – 1 tia High BA
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Cable
0.78mm 2-pin, 4.4mm Silver Plated UP-OCC Copper Litz Cable
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Material
904L Stainless Steel with DLC (Diamond-Like Carbon) Coating
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Frequency response
5Hz-22kHz
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SPL
103dB @ 1kHz, 1mW
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Crossover
Integrated 4-way Passive Crossover
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Impedance
6.3 ohms @ 1kHz
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Model
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Price
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$3,000
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