64 Audio U4s | Hybrid Dynamic + BA Universal IEMs

64 Audio U4s Delivers Flagship Tech at an Affordable Price

• Four-driver hybrid IEM delivers classic 64 Audio performance with a new twist
• The slate blue shell provides a bold, stylish look
• The Tia treble driver delivers crisp, clear highs with the new dynamic driver providing deep sub-bass
• Includes Apex modules for varying isolation, silver-plated copper cable, carrying case, and plenty of ear tips
• Check out our measurement of U4s

Bold New Look and Sound

Its ergonomic, anodized, aluminum shell houses a single dynamic driver, two BA drivers, and one patented tia driver, all weaved together with our patented Tia, LID, and Apex technology. The 4-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 frequency response of U4s 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 is in keeping the low-frequency rise 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.

Tune Your Sound with Apex and Eartips

The included Apex Modules and Eartips each have different sonic characteristics. You can use different combinations to accentuate different aspects of U4s's sound.

mX Module
Widest imaging with a reduction in noise isolation. Sub-bass response is diminished, giving you the ability to attenuate to your preferences based on music type and mix. It is ideally used for recordings that do not capture much sub-bass content while containing a lot of spatial information.

m12 Module
Developed for those who feel the bass drop between m15 and mX is too drastic. Perfect for tracks where the bass is slightly overpowering the rest of the spectrum. Increases mid-range punch (reduction by 1db-4db at 130hz-20hz.)

m20 Module
Greatly increases sub-bass response while keeping the mid-bass clean. Works great for overly bright mixes as it tilts the response towards low end. While
this module shrinks the sound-stage width, it works great for synth-heavy or modern pop music that doesn’t contain much acoustic spatial information. The m20 module also unlocks some of the missing sub information in older rock recordings (increase by 1db-2db at 40hz-20hz.)

Foam Tips
Narrows the mix and shifts HF resonant peak down. More secure fit.

Spinfit
Shifts HF resonant peak up. Best at handling microphonics and occlusion effects. The nozzle is decoupled well from the silicone touching the ear canal.

Wide Nozzle
Staging is less localized with better panning blend. Hits target frequency response curve with m15 module.

Specifications

• Transducer Configuration
  • (x1) Dynamic driver (Lows)
  • (x2) Balanced Armature drivers (Low Mids, High Mids)
  • (x1) Tia driver (Highs)
• Frequency Response: 10Hz – 20kHz
• Sensitivity: 107 dB/mW @ 1kHz @ 1mW (94mV)
• Impedance: 11Ω @1kHz
• Crossover: Integrated 4-way passive crossover
• Isolation
  • m20 Module: -20dB
  • m15 Module: -15dB
  • m12 Module: -12dB
  • mX Module: -10dB
• Cable
  • 0.23Ω total impedance
  • 7 x 7 x 4 Multi-twist
  • Silver-plated OCC copper wire
  • 26 AWG
  • 3.5mm termination
• 64 Audio 1 Year Warranty

In the Box

• 64 Audio U4s IEMs
• Leather carrying case
• TrueFidelity ear tips (S/M/L)
• Silicone ear tips (S/M/L)
• SpinFit ear tips
• Ear tip holder
• Black premium Silver-plated copper cable with 3.5mm
• 64 Audio Apex modules (mX, m12, m15, m20)
• 64 Audio Sticker