64 Audio U4s

A Quad Driver Hybrid UIEM

A quad driver hybrid UIEM featuring ground-breaking patented technologies originally developed for our flagship products in order to bring a wider audience closer to their music.

Design & Aesthetics

The U4s explores a bold new color aesthetic. The Slate Blue shell color was influenced by some of the world's most beautiful blue-dial timepieces while the unique faceplate pattern is inspired by Muonionalusta meteorite fragments. Both the faceplate and shell's illuminant properties give it a unique tone in varying lighting conditions.

Driver Configuration & Technology

Its ergonomic anodized aluminum shell houses a single dynamic driver, two balanced-armature drivers, and one patented tia driver; all weaved together with our patented Tia, LID, and Apex technology. The four-way crossover is elevated with the use of our proprietary electrical low-pass filter; reducing low-frequency distortion.

Customization & Cable

The assortment of included apex modules and ear tips are an invitation to further shape the sound based on preference and source material while the ultra-low impedance premium silver-plated copper cable ensures unimpeded signal transmission. The dissemination of tia technology within our product range brings that classic 64 Audio sound signature to a new price-point.

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. U4s features two major elements of the tia system: the tia driver and the tia single-bore design.

Air Pressure Exchange (Apex)

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 U4s: 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 4 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.

Electrical Low Pass Filter

A crossover circuit replacing traditional acoustic dampers which can introduce unwanted distortion through vibration and air turbulence. Rather than using acoustic dampers to filter unwanted frequencies after the driver produces them the electrical low pass filter lowers distortion by eliminating unwanted frequencies before they reach the driver.

Tia System Design

Rather than constricting the sound of the drivers by fitting a tube onto them, the complete Tia System reduces unwanted resonance and distortion by allowing the drivers to radiate freely into the single large Tia bore with no obstructions to the front of the drivers.

Apex Core

Apex Core is a deeper understanding of air movement within an earphone system. The 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

Due to the high crossover point between the drivers, Wave Sync was developed to ensure coherence; an 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.