Introduction 64 Audio U4s Universal IEM


64 Audio has just introduced a new universal IEM, which has been available as a custom for some time. This quad driver hybrid universal IEM features ground-breaking patented technologies such as Tia, LID and Apex originally developed for their flagship products in order to bring a wider audience closer to their music. U4s explores a bold new color aesthetic for 64 Audio. The Slate Blue shell color was influenced by some of the world’s most beautiful 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.


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 electronic low-pass filter; reducing low- frequency distortion. 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. U4s sounds light on its feet while effortlessly delivering physically engaging sub- bass without bleeding into the mid-bass. Balanced mid frequencies and a pleasant high-mid band respond well to a wide array of music and recording styles at every volume level; present but not fatiguing. The tia high-driver’s open airy quality couples with the extended sound-stage provided by apex for a lifelike sonic experience.



The wide nozzle silicone tips and m15 modules gives a frequency response of U4s that follows proven targets for fidelity and preference. It’s powerful, enveloping, and deep while avoiding being muddy; this kind of bass can only be produced by a dynamic driver. U4s comes short of being classified as warm, rather it is like a tight and agile stand-mount speaker with a well implemented sub. The key to this is how the low-frequency rise starts low enough to keep out of the mid-bass.
Mids are revealing and present, contributing greatly to its wide stereo imaging and separation. U4s’ perfect balance of presence and body lends itself well to every type of music and volume preference. High frequency response toes the line between neutral and detailed. Mixes that are typically “bright sounding” translate nicely without being harsh or fatiguing.


New Apex Module

Air Pressure Exchange 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 four module variations for U4s: mX, m12, m15 and m20.


The new M12 Apex module has been developed for those who felt that the bass drop between m15 and mX was too drastic. Perfect for tracks where the bass is just slightly overpowering the rest of the spectrum. Increases mid-range punch. (reduction by 1db-4db at 130hz-20hz). The  difference in modules can be best explained as: MX module has the widest imaging with a reduction in noise isolation. Sub-bass response is greatly diminished, giving you the ability to attenuate to your preferences based on music type and mix. The M20 module greatly increased sub-bass response while keeping the mid-bass clean.



Drivers: 2 balanced armature drivers, 1 tia driver, and 1 dynamic driver
Configuration: 1 dynamic low, 1 BA low-mid, 1 BA high-mid, 1 tia high
Frequency Response: 10Hz – 20kHz
Sensitivity: 107 dB/mW @ 1kHz @ 1mW (94mV)
Impedance: 11Ω @1kHz
Crossover: Integrated 4-way passive crossover
Isolation: -20dB w/ m20 module -15dB w/ m15 module -12dB w/ m12 module -10dB w/ mX module
Cable: 0.23 Ohms total impedance, 7 x 7 x 4 Multi-twist, Silver plated OCC copper wire 26 AWG


Pricing & Dealers

64 Audio U4s Universal IEM MSRP €1349

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