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 the 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 deploy a dual Helmholtz Resonator for precise tonal adjustments.

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.

Helmholtz Resonator Technology

While planar magnetic technology has been present in portable hi-fi for many years, we wanted to truly showcase its potential in our products. To offer a new perspective on this technology, we needed a combination of a slight but broad reduction in high-frequency amplitude and the attenuation of a few very narrow frequency bands. As the electronic filter acts as a very subtle reductive shelf, we had to think creatively to effectively control some problematic frequencies. For this, we drew on our years of research into Helmholtz Resonators, an acoustic device from the mid-19th century. The two micro-cavities, 3D printed into Solo's sound chamber, operate by forcing air in and out, causing the air inside to resonate at a specific frequency. By precisely determining the dimensions of the cavity and its neck, we can target a very narrow resonant frequency to amplify or diminish.

Planar Magnetic Driver Design

The planar magnetic driver features a flat diaphragm with embedded conductors suspended between two sets of magnets, unlike traditional dynamic drivers that utilize a conical diaphragm driven by a voice coil. Because the entire diaphragm moves uniformly due to the planar magnetic field, we can deliver the detail and micro-transient information that would typically require a dedicated high-frequency driver. Since the diaphragm isn't driven by a voice coil attached to a cone, which can cause uneven movement, we can reliably extract a true high-resolution full range sound from this single driver.

Tubeless In-Ear Audio System

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

Apex Core Pressure Relief

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.

Linear Impedance Design

Linear Impedance Design (LID) is a patented circuit that compensates for the non-linear electrical resistance resulting from Solo's electronic shelf filter. Variations in source amplifier output impedance in devices like smartphones, body packs, DAC/amps, and DAPs typically lead to changes in frequency response. LID restores proper interaction with the source, preserving the intended sound signature and ensuring consistent, reliable performance.