U18s
Eighteen Driver Universal In-Ear Monitor
Made in the USA
64 Audio revolutionized the IEM industry with its world class reference level U18t, the world’s first 18-driver earphone.
Now, with the introduction of U18s, 64 Audio has taken the heritage of the 18-driver platform and further pushed the envelope of design innovation, creating a new relaxed tuning and completely different flavour of sound.
U18s combines proprietary drivers, LID technology and a new electronic crossover network to deliver a uniquely exceptional listening experience.
This IEM is handcrafted in the USA from aerospace-grade aluminum billet. CNC milled, sand blasted, fly cut, and twice anodized — the result is a striking fractal design that is inspired by nature itself.
Listening to U18s gives the sense that a filter has been lifted off of your music; it is suddenly more direct and vibrant. Resolution and presentation that reveals details which have previously gone unnoticed. The space between you and the performance is removed; the difference between hearing the best reproduction and experiencing it being played in real-time. The enveloping sound-stage and wide frequency response allows you to really press into the music without fear of harshness or fatigue.
It's a more relaxed listen than the popular U18t, with a tuning that takes inspiration from the warmth and smoothness of the best-selling U12t. Listeners love the added focus on rich sub-bass and reduced brightness, allowing for longer listening sessions and minimizing fatigue over time, even at higher volumes.
You'll enjoy terrific imaging, with clear positional cues and an elusive centre image. And of course, the 18-drivers work in concert to produce top-tier detail retrieval, with added texture.
U18s features exclusive technologies that challenge traditional in-ear monitor designs to give you the absolute best listening experience.

Tubeless In-Ear Audio
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. U18s features two major elements of the tia system:
The tia driver is an open balanced armature speaker design that brings new meaning to resolution and transparency. It delivers airy, crisp, and microdetailed upper frequencies with characteristics not often found in a headphone or in-ear monitor. 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.

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.
Apex is implemented in U18s via branded interchangeable modules, so you can quickly switch between different levels of isolation and sound signatures. Although the modules technically only affect the low frequencies, this psychoacoustically affects your perception of the whole frequency range.
- The m20 module (-20dB noise isolation) offers the most relaxed presentation with rich sub-bass. Experience the type of isolation you'd expect from a conventional IEM, minus the ear fatigue.
- The m15 module (-15dB noise isolation) is fitted to U18t by default, for a balanced signature and airy presentation that allows you to hear some more of your surroundings.
- The mX module (-10dB noise isolation) lowers the bass quantity, opening up the soundstage, enhancing instrument layering, and reducing isolation even further for ambient awareness.
Linear Impedance Design
Smartphones, body packs, amps, and DAPs produce audio with different output impedances. The interaction of the earphone impedance curve with the sources may result in the same IEM sounding different with different sources.
LID is a proprietary circuit that corrects the non-linear impedances of the multiple driver-sets that comprise this eighteen-driver IEM, restoring proper interaction with the source and preserving the desired sound signature, so you can enjoy the same sound reliably across sources.
Electrical Low Pass Filter
An acoustic damper (old technology) doesn’t actually prevent frequencies from getting to the driver, it merely blocks frequencies from getting to the ear. At higher volumes acoustic dampers can introduce unwanted distortion through vibration and air movement.
64 Audio's electrical low pass filter lowers distortion by eliminating unwanted frequencies. It does this with an electrical circuit that eliminates target frequencies before they even reach the driver.
CABLE

U18s is unique in the 64 Audio lineup, in that includes a premium 8-braid cable in silver.
It features branded bifurcation, soft touch jacketing for minimized cable noise, and angled 2 pin connectors with memory wire.
- .28ohm
- 8-Braid
- Pure silver plated oxygen-free coper wire
- 65 Strands of 44awg wire
- Low microphonics
- .78mm pins
IN THE BOX
- U18s Universal In-Ear Monitors
- 64 Audio Premium Leather Case
- TrueFidelity Eartips (S,M,L)
- Silicone Eartips (S,M,L)
- SpinFit Eartips (S,M,L)
- Premium 8-Braid Cable in silver
- Branded m20 apex Modules
- Branded m15 apex Modules
- Branded mX apex Modules
- Round Sticker
SPECIFICATIONS

Driver Type/Count
Eighteen precision balanced armature drivers
Driver Configuration
1 tia high, 1 high-mid, 8 mid, 8 low
Sensitivity
106 dB/mW @ 1kHz @ 1mW (84mV)
Impedance
8Ω Nominal
Crossover
Integrated 4-way passive crossover
Isolation
-20dB with m20 apex module
-15dB with m15 apex module (default)
-10dB with mX apex module
For hygienic reasons, there are no returns on earphones once opened.
All our 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.