Наушники — Astell&Kern 64 Audio XIO

XIO is a hybrid universal in-ear monitor and the first joint product of Astell&Kern and the in-ear monitor company 64 Audio. A first teaser appeared at the Munich High End exhibition in May 2025, and the product went on sale worldwide in August 2025 at USD 3,000. Engineers in the United States designed, assembled and quality-checked each pair.

Key specs that matter

Each earpiece holds ten drivers split by a four-way passive crossover. Two dynamic drivers handle the low end, six balanced armatures cover the midrange, one more balanced armature takes the upper mids, and a tia balanced armature reproduces the treble. Published frequency response runs from 5 Hz to 22 kHz. Sensitivity is 103 dB SPL at 1 kHz with 1 mW, and impedance measures 6.3 ohm at 1 kHz. The earpieces take a 0.78 mm 2-pin cable, and the supplied lead ends in a 4.4 mm balanced plug.

Engineering and use context

Both dynamic woofers work in what 64 Audio calls a True Isobaric Dual-Dynamic Bass structure, synchronised with each other through a coupling chamber that 64 Audio describes as acoustically inert. The tia high-frequency driver radiates directly without the usual sound tube, part of the Tubeless In-Ear Audio concept with a single-bore nozzle intended to reduce resonance and distortion. Apex (Air Pressure Exchange) venting releases pressure in the ear canal to limit listening fatigue, and four interchangeable Apex modules come with the set - m20 Silver, m15 stainless steel, m12 Gold and mX Black, with the m15 made specifically for the XIO from DLC-coated 904L steel. LID (Linear Impedance Design) compensates for the nonlinear electrical resistance of the drivers. Shells are precision-milled from 904L stainless steel, coated in black Diamond-Like Carbon and finished with a three-dimensional faceplate. The cable is a four-core cross-braided Litz design using silver-plated UP-OCC copper, with an impedance of 0.29 ohm. The box also contains a 64 Audio leather case, TrueFidelity foam tips, SpinFit silicone tips and standard silicone tips in three sizes each, plus a cleaning tool, cloth and cable clip.

Pairing

Because the stock lead terminates in a balanced plug, the XIO connects directly to a digital audio player, dongle DAC or headphone amplifier fitted with a matching balanced socket.

Alternatives

The Astell&Kern Pathfinder, developed with Campfire Audio, is a hybrid in-ear monitor with two custom 10 mm dynamic drivers and three balanced armatures priced at USD 1,900.