64 Audio Fourte
Four Driver Universal In-Ear Monitor
Made in the USA
The pinnacle of in-ear monitor technology, Fourté takes full advantage of everything we've learned in designing world-class in-ear monitors for the foremost technical performance.
Fourté boasts some of the most detailed, dynamic sound and widest soundstage for an in-ear monitor, making it a uniquely-tuned choice for audiophiles and music lovers seeking detailed audio and three-dimensional listening.
Fourté features our complete, three-part tia™ system housed in an ergonomic shell, machined from a solid piece of aluminum and finished with elegant, copper patina faceplates.
The Fourté features a unique audiophile-inspired tuning that must be heard to be understood — a unique sound signature that is without parallel when it meets the ears of the right listener.
It features a meaty sub-bass contrasted with a brighter treble achieved through the tia driver system, delivering maximal detail from your music.
Fourté is one of the most dynamic IEMs, with vibrancy, vigor, and weight to its notes. Its imaging creates an industry benchmark, with instruments truly distinct in space. Staging is immensely wide. And detail retrieval is simply thrilling, with jaw-dropping texture and feel.
Fourté features exclusive technologies that challenge traditional in-ear monitor designs to give you the absolute best listening experience.

Tubeless In-Ear Audio
The story of tia is the story of Fourté. Developed over many years, 64 Audio's tia is a patented IEM design methodology that aims to reduce unwanted resonance and distortion for a transparent and lifelike sound signature. Fourté features all three major elements of the tia system:
The tia driver is an open balanced armature speaker design that brings new meaning to resolution and transparency. Fourté features two of these drivers per side. By opening a balanced armature, the diaphragm becomes fully unobstructed, unleashing the sound potential of the driver. This eliminates a lot of the vibrations and resonances that are inherent in conventional, closed balanced armature designs. With this new method of producing and delivering sound to the ear, conventional sound tubes and dampers are no longer necessary.
The tia single-bore design is a huge leap forward in eliminating unwanted tube resonance. The large bore itself serves as a sound-shaping chamber and aids the tia high driver in delivering a linear and coherent frequency response. Because of the extremely short sound path of the tia high driver, a remarkable high-frequency extension and smoothness is achieved. The large single bore also helps prevent clogging of the tip and obstruction of sound.
The tia acoustic chambers further shape the sound of the tia driver. This chamber optimizes driver performance by giving it its own space, and tunes the drivers without introducing unwanted resonances. Each driver is perfectly matched to its acoustic chamber just like a pair of speakers are tuned to a studio control room, delivering a three-dimensional soundstage unmatched by any other IEM.
In the long list of groundbreaking tech packed into Fourté, its passive radiator often doesn't get the credit it deserves. This membrane between the shell and the faceplate is passively excited by the vibrations of the drivers within the shell.
This element increases the unique width of the soundstage of Fourté. Since soundstage is difficult to measure, Fourté’s passive radiator was implemented through careful listening tests.

Air Pressure Exchange
Apex is a patented vent that releases air pressure in a sealed ear canal all while retaining a level of isolation; this venting alleviates listener fatigue and allows for a much more realistic soundstage.
When you seal a miniature speaker in an ear canal, the air inside becomes trapped. As the speaker produces sound, it moves the air and causes the eardrum to work excessively. The pneumatic pressure exerted on the eardrum causes ear fatigue. Apex relieves this pressure, allowing the eardrum to move naturally, so you can comfortably listen longer.
Apex enables air to move freely in the ear canal, which extends the perceived soundstage and allows for a more natural listening experience. Everything from inserting, wearing, and removing the IEMs becomes a much more natural and painless process.
In order to preserve the tia acoustic chambers, Apex is integrated in Fourté all the way down to the way the shell is milled, offering similar pressure release and isolation to our m20 module.
CABLE

Tia Fourte's packaging and accessories have been updated, and now includes a new, low resistance cable in black.
It features a branded straight 3.5mm metal jack, as well as a metal synch and branded metal bifurcation.
Our classic angled 2-Pin connectors are situated at the end of an ergonomic curve in the cable to accommodate a comfortable fit around the ear without a memory wire. The new soft jacketing minimizes tangling and microphonic noise.
- .78mm Pins
- 0.23 Ohms Total Impedance
- 7 x 7 x 4 Multi-Twist
- Silver Plated OCC Copper Wire
- 26 Awg
IN THE BOX
- Fourté Universal In-Ear Monitors
- 64 Audio Premium Leather Case
- TrueFidelity Foam Eartips (S,M,L)
- SpinFit Silicone Eartips (S,M,L)
- Silicone Eartips (S,M,L)
- 48" Black Premium Cable
- Round Sticker
3 precision BA drivers, 1 dynamic driver
Driver Configuration
1 tia high, 1 high-mid, 1 tia mid, 1 dynamic low
Sensitivity
114db @1kHZ @1mw
Impedance
Crossover
Integrated 4-way passive crossover
Isolation
-20dB internal apex technology
For hygienic reasons, there are no returns on earphones once opened.
In-stock earphones are available for personal demonstration in-store. We encourage you to try before buying to ensure satisfactory sound, fit, and functionality.
If an item is defective upon receipt, please notify us within 30 days of purchase so we can arrange an exchange. For issues following 30 days, we will work with you and the manufacturer within the scope of each brand’s warranty and service policies.