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.

64 Audio A2e custom in-ears on blue surface

A2e Story

A2e is a two driver custom in-ear monitor (CIEM). The two drivers per ear are crossed over once so there’s a dedicated driver for higher frequencies and a larger dedicated driver for lower frequencies. Since this is such a succinct design, and simple system, it ends up being our lowest cost CIEM. While some people might know 64 Audio for our flagship monitors that hold the spot for some of the highest cost IEMs in the world, we are simultaneously one of the most cost-competitive staple brands in the industry.

As with all of our products we couldn’t just make something to fit into a price bracket and be done with it. While A2e is $50-$150 more affordable than the entry level products of our closest competitors its sound and build quality rival products twice the price. The reason for this is how technological innovation flows at 64 Audio. Everything we learn in developing products like Fourté and A12t ends up trickling down to all of our products, including A2e.

The custom A2e is one of our only CIEMs that received a major update in 2018 without a re-brand and name change. The biggest update was its new integrated circuit, the addition of our patented LID technology and single-bore design borrowed from our patented tia technology. LID allows you to use your A2e through different devices and expect a consistent frequency response between all of those devices. The single bore is an alternative to the standard multi-bore design that has made CIEMs so difficult to clean and maintain. With all of our CIEMs you just have one large opening which is a lot easier to keep debris and wax out of. A2e is also built with our patented 3Dfit process and utilizes our patented Apex technology. After extensive listening tests and prototypes, the newly updated A2e came out the other side a full fledged full-range CIEM.

64 Audio A2e custom in-ears in front of acoustic guitar strings

A2e Sound

While developing A2e one of the main focuses in our listening tests was the vocal region of the mid frequency band. We wanted A2e to be a robust monitoring option for vocalists, especially folks who volunteer as singers at church on the weekends. While that was one of the main goals, we completely over-did it and gave it more than adequate bass for the most dynamic drummers and clear extended highs so you don’t miss the airiness of vocals, the length effects tails, and transient percussive details.

Comparing A2e to the rest of our CIEM models you hear a common thread. 64 Audio’s signature balanced sound unites our whole product range. A2e is a natural, balanced, and musical IEM. It is also designed to match well to the widest array of peripheral gear. It’s one of our highest sensitivity models, which means you won’t have turn your volume knob up as high and its impedance is closer to other headphone/earphone solutions at 30ohms.

64 Audio A2e custom in-ears in front of blue drums

I use the A2e almost the most. I just feel comfortable traveling with them, they fit really well, they sound amazing. Because I don’t do a lot of full blown mixes, I’m just playing drums by myself, it’s SO more than enough. I love the A2e!

Mike Johnston (

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.

earphones aligned on a white background to form a 64 Audio logo

A2e Specs

  • Transducer Type/Count: Two precision balanced armature drivers
  • Transducer Configuration: 1 high, 1 mid/low
  • Bore Configuration: Single
  • Freq. Response: 20Hz – 18kHz
  • Sensitivity: 114 dB/mW
  • Impedance: 30Ω @ 1kHz
  • Crossover: Integrated 2-way passive crossover
  • Isolation: -20dB with m20 apex module

A2e Technology

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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 A2e: mX, m15 and m20.

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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.

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Linear Impedance Design (LID) is a patented circuit that corrects the non-linear electrical resistance of the multiple driver-sets comprising this 2 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.