Full-Range Sound Innovation

Redefining the meaning of "full-range sound" in portable high-end audio, Solo expertly covers the entire sonic spectrum with a single planar driver. The final note in our legendary tia™ line of UIEMs has been years in the making. Staying true to the tech-disruptive legacy of Fourté, Trio, and Duo, we looked to the past for innovative solutions to the modern challenge of tuning a single driver. In addition to a traditional electronic filter that subtly shifts the tonal balance, we have introduced the world's first Helmholtz resonator in an IEM.

Sound Performance

U12t does it all, delivering immersive sound and impeccable spatial imaging. Its articulate highs extend beautifully with a warm and engaging low-end response - just like its custom counterpart, the A12t.

Advanced Driver Technology

The 14.2mm planar driver's acoustic chamber integrates two Helmholtz resonators, meticulously tuned to acoustically sculpt its frequency response. This chamber is also engineered to include our apex core design, expertly relieving pneumatic pressure and enhancing the sense of physical space to a degree never before experienced in a single-driver IEM. Combined with our patented LID technology, all of these innovations are housed in our most striking design update since the introduction of Fourté in 2016. These elements unite to deliver a sound that is quintessentially 64 Audio, combining the exceptionally detailed transient response of planar technology with an unexpectedly robust low-frequency presence.

Build Quality and Design

Offering reference-level detail, this IEM has become one of the most highly regarded and sought after audiophile UIEMs. Each ergonomic shell is machined out of a solid piece of aluminum and finished with an electroformed stainless steel faceplate chip.

Tubeless In-Ear Audio (tia)

Tubeless In-Ear Audio (tia) is a patented IEM design methodology that aims to reduce unwanted resonance and distortion for a transparent and lifelike sound signature. The tia system is comprised of three major elements: open balanced armature tia drivers, the tia single-bore design, and tia acoustic chambers. U12t features two major elements of the tia system: the tia driver and the tia single-bore design.

Apex Core Technology

Air Pressure Exchange (Apex) is a patented vent that releases air pressure in a sealed ear canal all while retaining standard IEM levels of isolation; enabling musicians and music enthusiasts to listen more comfortably for longer. This venting alleviates listener fatigue and allows for a much more realistic soundstage. Apex comes in three module variations for U12t: mX, m15 and m20.

Linear Impedance Design (LID)

Linear Impedance Design (LID) is a patented circuit that corrects the non-linear electrical resistance of the multiple driver-sets comprising this 12 driver IEM. Varying source amplifier output impedance in devices like smartphones, body packs, DAC/amps, and DAPs typically results in varying frequency response across them, depending on the increase in resistance. Restoring proper interaction with the source and preserving the desired sound signature enables a consistent reliable sound.

Comfort and Fit

Adding to our list of innovations, we implement our patented pressure-relieving technology in the form of apex core, elevating this design to new levels of fidelity and spatial acuity. Because Solo's acoustic chamber includes our integrated apex core technology, we achieve a similar fit and comfort to that of the Duo. The design offers just enough isolation to allow the listener to focus on the audio while feeling so unoccluded that you may initially wonder if you have a proper seal. This ensures hours of comfortable listening, made possible by our patented technology.

Complete Tia System

Rather than constricting the sound of the drivers by fitting a tube onto them, Duo's complete Tia System reduces unwanted resonance and distortion by allowing the 9mm Dynamic Driver + Tia High Driver to radiate freely into the single large Tia bore with no obstructions to the front of the drivers.

Apex Core Airflow Design

Apex Core is a deeper understanding of air movement within an earphone system. Duo's faceplate features a striking perforated grill that leaves the shell of the IEM open to the outside atmosphere for a less obstructed airflow resulting in an effortless reproduction of music and minimal physical fatigue.

Wave Sync Coherence Technology

Due to the high crossover point between the two drivers, Wave Sync was developed to ensure coherence; another industry first. By using a type of "all-pass" filter, we're able to introduce a crossover while correcting for time without having to change the physical distance between the drivers.