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    $1,099.00

    A complete redesign of our four driver platform is elevated by the Dynamic low frequency driver, making this 64 Audio’s second hybrid custom IEM. Along with that major update, inside A4s is our Tia technology, LID and our patented Apex and 3Dfit tech. While this is targeted at musicians looking for a rich enveloping monitoring experience, the frequency response, detail, and soundstage capabilities of A4s exceed other audiophile products at almost any price point.

    Estimated build time: 6 Weeks
    Order Now

    TECHNOLOGY

    Exclusive technologies that challenge traditional in-ear monitor designs to give you the absolute best listening experience

    learn more about all of our technologies

    A4s features the following unique technology:

    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. A4s features two major elements of the tia system: the tia driver and the tia single-bore design.

    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 available for A4s: mX, m15 and m20.

    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.

    3D-Fit preserves the detail of your ear impressions using a new process of digital rendering and 3D-printing. The patented process of incorporating acoustical tuning features within an IEM’s shell allows for designs that would otherwise be impossible to build using traditional methods. We incorporate these advanced and uniquely complex features into the shell in order to manipulate the audio produced by the IEM. This process also reduces distortion in the impression for the most precise and comfortable custom in-ear monitors available.

    SPECIFICATIONS

    New Column New Column-20dB with m20 apex module

    Transducer Type

    Dynamic & Balanced Armature

    Transducer Configuration

    1 dynamic low, 1 BA low-mid, 1 BA high-mid, 1 tia high

    Bore Configuration

    Single

    Frequency Response

    10Hz – 20kHz

    Sensitivity

    107 dB/mW (94mV) @ 1kHz

    Impedance

    11Ω @ 1kHz

    Crossover

    Integrated 4-way passive crossover

    Isolation

    20dB w/ m20 module, -15dB w/ m15 module.

    Ships with M20 Module standard

    Designed, Assembled, and QC’d by highly skilled technicians in the United States using components sourced both domestically and globally from trusted suppliers.

    IN THE BOX

    • A4s Custom In-Ear Monitors
      64 Audio Personalized Protective Case
      Dehumidifier
      Cleaning Tool
      Shirt Clip
      48" or 64" Detachable Professional Cable
      m20 apex Modules

      Round Sticker
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