Skip to content
Available for pre-order. Delivery July/August 2025
64 Audio x Astell&Kern
XIO is the result of Astell&Kern and 64Audio's shared philosophy of design and sound. Combining precise engineering with artistic sensibility, XIO goes beyond simply playing music. It transforms sound into a tangible experience, offering value that exceeds all expectations.
Designed as a true work of art, XIO sets a new standard for high-end in-ear monitors – an uncompromising fusion of aesthetics and acoustics that sets new standards.
Designed as a unique object, XIO sets a new standard for high-end in-ear monitors with its uncompromising approach to aesthetics and acoustics.
Thanks to a team of top professionals and proprietary patented technologies, 64 Audio has established itself as an innovative company pushing the boundaries of IEMs.
"XIO boldly opens a new chapter in the development of high-end in-ear monitors. It goes beyond simply reproducing sound—it embodies our philosophy of shaping sound itself. By combining mechanical perfection with musical sensitivity, XIO creates added value that exceeds all expectations."
Internal structure
01. tiaⓇ Waveguide
02. 0.78 mm 2-pin 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
Designed for precision
XIO has been carefully designed both inside and out.
Its advanced hybrid system with ten high-performance drivers is finely tuned with a 4-way passive crossover to ensure that all frequencies are in perfect harmony.
This precise tuning ensures a realistic sense of depth and a rich, spatial soundstage.
10-driver hybrid system
tiaⓇ waveguide
The tiaⓇ driver features a direct-radiating structure that eliminates the need for a conventional sound duct and enhances the refinement of high frequencies. This design minimizes attenuation and distortion, while the precisely positioned driver, combined with a dedicated waveguide system, delivers a deep sense of space and airy, detailed highs.
BA driver
The mid and upper mid frequencies are reproduced by six and one balanced armature drivers, respectively, providing smooth transitions and rich texture. Vocals, instruments, and their unique harmonic details are reproduced warmly and clearly, creating a natural and 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, allowing for precise control. This design delivers bass with exceptional depth and density, as well as a powerful sound impact that exceeds what's typically possible with conventional IEMs.
Patented technology
Tubeless In-Ear Audio (tia) is a patented IEM design that minimizes resonance and distortion, delivering clear and vibrant sound.
The tia system consists of the tia driver, a single-bore design, and an acoustic chamber. XIO utilizes the tia driver and single-bore structure to capture the pure essence of sound.
apex (Air Pressure Exchange) is a patented ventilation system that naturally releases pressure from the closed ear canal while providing excellent noise isolation.
This technology reduces listening fatigue during extended sessions and provides a much wider, more realistic soundstage.
The m15 module, which is standard on XIO, has been redesigned specifically for XIO with a DLC coating on 904L stainless steel, making it a unique apex solution available exclusively for this model.
Linear Impedance Design (LID) is a patented circuit that compensates for the non-linear resistance between the drivers, ensuring consistent sound quality regardless of changes in the output impedance of the source device.
This technology ensures stable sound and precise frequency response at all times.
Precision-milled 904L stainless steel shell
The exterior of the XIO goes beyond that of a typical IEM and stands out as an “audio work of art” that appeals to both the visual and tactile senses.
Its robust structure is created by precisely machining 904L stainless steel—a material that is harder and more difficult to work with than conventional stainless steel—and then coated with a luxurious black DLC (Diamond-Like Carbon) coating for an exceptional premium texture.
The front panel reflects Astell&Kern's design heritage, conveying a three-dimensional and elegant presence through deep shading and delicate reflections.
Silver-plated UP-OCC copper Litz cable
This cable, specially developed for XIO, is designed to create a perfect aesthetic harmony with the earphones. The four-conductor, cross-braided cable is made of silver-plated single-crystal copper (UP-OCC) and provides excellent noise isolation and transparent signal transmission.
With a low impedance of only 0.29 Ω, it maximizes electrical efficiency.
Handmade IEMs from the USA
64 Audio uses carefully selected components from trusted partners around the world. Every step of design, assembly, and quality control is meticulously performed by experienced engineers in the United States.
Scope of delivery
- XIO Universal In-Ear Monitors
- 64 Audio Premium Leather Case
- TrueFidelity foam eartips (S, M, L)
- SpinFit silicone earplugs (S, M, L)
- Silicone earplugs (S, M, L)
- Cleaning tool
- cleaning cloth
- cable clip
- 4.4 mm silver-plated UP-OCC copper Litz cable
- Apex modules: m20 (silver), Special m15 (904L stainless steel with DLC coating), m12 (gold), mX (black)
General specifications
- Drivers 2 Low DD – 6 Mid BA – 1 High-Mid BA – 1 tia High BA
- Cable 0.78 mm 2-pin, 4.4 mm silver-plated UP-OCC copper Litz cable
- Material: 904L stainless steel with DLC coating (Diamond-Like Carbon)
- Frequency response 5 Hz–22 kHz
- SPL 103 dB at 1 kHz, 1 mW
- Crossover Integrated 4-way passive crossover
- Impedance 6.3 ohms at 1 kHz
