Custom IEM Model Overview 

64 Audio makes nine custom in-ear monitor (CIEM) models ranging from 2-18 drivers per side which cost between $499-$2,999. Our goal with the whole product range is to offer the best possible sounding monitor at each price point. Regardless of driver-count we aim to get the most out of components for balanced, accurate and musical IEMs. All of our models reflect that signature sound, and with the increase of drivers and cost you get increased fidelity/resolution.

For more IEM info take a look at our Educational Series.

black and white custom A3t earphones on white background

A3t Story

The A3t Custom In-Ear Monitor is one of our three driver custom fit IEMs, the other being our A3e. We don’t have many models that share driver counts, the only others are our A18t and A18s. A3t was a way for us to get our patented tia technology into an even more affordable IEM, a theme throughout 64 Audios history; trickling flagship technology into every possible price point. Although A3t released in 2021 this had been floating around the building since around 2017 and refined into what it is today. Not only is our tia technology available in this new lower price point, but A3t also features all of our other patented technology like LID, Apex and 3Dfit.

The goal with A3t was simple: make a reference monitor that rivals products more than 5x its price, this simple yet powerful arrangement of balanced armature drivers and crossover components achieves that perfectly. Two-balanced armature drivers and one tia high-driver are paired with a 3-way crossover so you have a single driver dedicated to all three major frequency bands: highs, mid, and lows. This is a perfect tool for any audio engineer or musician looking for a neutral, balanced and musical reference monitor for live and recorded performance.

64 Audio A3t custom in-ears on poster

A3t Sound

One of the first things you think when playing your initial reference track is “this sounds right,” pure and simple. Usually when listening to an audio product, especially as a skeptic, you are able to quickly latch onto something that could’ve been done better, A3t just reproduces the mix without anything distracting you from the music. Everything sits in its proper place; capable bass, present mids, smooth yet detailed highs. To fans of the A6t and A12t this will be a very familiar sound.


64 Audio custom A3t in-ears on aluminum case

The A3t is simply powerful and satisfying, my mixes on them pulled up strong, deep and glossy! No concerns from me in recommending them to anyone wanting something strong and enveloping!

Brad Law (Monitor Engineer Hillsong UNITED)
64 Audio custom A3t in-ears next to aluminum case

They sound phenomenal…Perfect balance for my use. I think they’ll be great for FOH, listening to music, mixing critically, all the things I need. Really impressed.

Lee Fields (MxU, FOH Hillsong UNITED)

Custom-Fit, Custom-Look, & Custom-Made

Each 64 Audio CIEM is hand built in Vancouver Washington by highly specialized technicians.

Ear impressions are first trimmed and scanned into our 3D detailing software. Our patented 3Dfit technology is used to perfectly recreate the intricacies of your ear shape. We virtually accommodate for all of the internal components before 3D printing with hypoallergenic acrylic material.

Once the shell is printed our assemblers insert the pre-soldered driver packs associated with the model of the IEM.

hands assembling 64 Audio custom in-ears under microscope

The assembled CIEMs are later completed with a faceplate. Along with the 5 shell options, there are dozens of faceplate colors and materials which translates to hundreds of variations. On top of all of those options we’re also able to use custom artwork to make your IEMs truly one-of-a-kind.

A3t Specs

  • Transducer Type: BA
  • Transducer Configuration: 1 High, 1 Mid, 1 Low
  • Bore Configuration: Single
  • Freq. Response: 20Hz – 20kHz
  • Sensitivity: 109dB/mW (109dB @ 1kHz @1mW (105mV))
  • Impedance: 11Ω @ 1kHz
  • Crossover: Integrated 3-way passive crossover
  • Isolation: 20dB w/ m20 module, -15dB w/ m15 module
  • Ships with M20 Module standard

A3t Technology

Air Pressure Exchange (Apex) is a patented vent that releases air pressure in a sealed ear canal. In addition to relieving air pressure, it also maintains standard IEM levels of noise isolation. The attenuation of ambient noise and pressure relief enables 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 A3t: mX, m15 and m20.

Tubeless In-Ear Audio (tia) is a patented technology that reduces unwanted resonance and distortion for transparent and lifelike sound. Tia is comprised of three major elements: open balanced armature tia drivers, the tia single-bore design, and tia acoustic chambers. A3t features two major elements of the tia system: the tia driver and the tia single-bore design.

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 the shell allows for designs that would traditionally be impossible. We incorporate these advanced and 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.

Linear Impedance Design (LID) is a patented circuit that corrects the non-linear electrical resistance balanced armature drivers. Varying source-amplifier output-impedance typically results in varying frequency response across devices, depending on the increase in resistance. Restoring proper interaction with the source and preserving the desired sound signature enables a consistent reliable sound.

A3t Testimonials