Thieaudio at Audio46

Thieaudio Monarch MKIII (Custom Design) Electrostatic Universal In-Ear Monitor





Product SKU: Black Bat (4) + Butterfly (A4)


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Product Details

Audio46's Opinion

The Monarch III is insanely good in every conceivable way, from it's deep, nimble and highly detailed bass, to its pristine midrange and vivid soundstage. And many audiophiles may be left wondering why Thieaudio didn’t set a higher price point. This is because, without question, the Monarch III proves to be one of the most talented and most memorable IEMs in its class, firmly carving it’s place next to the few other $1k greats, such as the Andromeda and Meze Rai Penta.

Our Full Review

↓ Details provided by Thieaudio

This is the custom design. We also offer the DEFAULT DESIGN Monarch MKIII.

For faceplates “Butterfly (A4)” and “Disco (A5)”, ONLY “Black Bat” shell can be chosen


2DD+6BA+2EST Flagship IEM

IMPACT2: THIEAUDIO's latest innovation in personalized audio with a powerful subwoofer solution using isobaric design and composite diaphragm drivers.

Enhanced Ultra-Treble Output: The Monarch MKIII now features Sonion's electrostatic drivers and increased frequencies for a more comprehensive upper frequency extension, resulting in improved staging and resolution.

Balanced Tonal Signature: The Monarch MKIII maintains a studio-monitor-like tonal excellence with clean, natural, and detailed sound, while offering a focused sub-bass impact.

Improved Bass Quality: The addition of another 10mm subwoofer in IMPACT2 enhances the power and texture of the bass without compromising tonal integrity, providing better bass quality for an immersive audio experience.

Thieaudio Monarch MKIII Custom Overview

The IMPACT2 (“Impact Squared”) is THIEAUDIO’s latest technological innovation to change the personalized audio industry.

IMPACT2 is a new subwoofer solution consisting of two 10mm composite diaphragm drivers arranged in an isobaric design. The addition of another 10mm subwoofer significantly enhances the power and texture of the bass, while our in-house isobaric chamber design keeps the frequency and pressure constant. This means you can enjoy better quality bass without sacrificing tonal integrity.

With updated drivers, tuning strategies, and significantly improved ergonomics, the Monarch MKIII offers the legendary performance of the MKII with enhanced technicalities and comfort.

Thieaudio Monarch MKIII Custom Impact2

Monarch, Pushing beyond the Pinnacle

At their times, the original Monarch and the Monarch MKII set new standards for best-in-class performance in the global IEM industry. Not only did it redefine the price-to-performance bracket, but it forever changed how IEM manufacturers engineer and tune IEM’s. Keeping with the times, the Monarch has undergone another revision to revamp its technical and tonal performance.

Thieaudio Monarch MKIII Custom Front Face

Enhanced Ultra-Treble Output

The Monarch MKIII has been updated with Sonion’s latest electrostatic (EST) drivers and re-tuned to better exhibit these drivers’ full potentials. Thanks to our new tuning strategy, the ultra-treble frequencies at +15kHz to 20kHz have been increased for a more comprehensive upper frequency extension. Compared to its predecessor, the Monarch MKIII will have a greater sense of staging, atmosphere, and an overall enhancement in perceived resolution thanks to the treble extension.

Thieaudio Monarch MKIII Custom Design Faceplate

Balanced Tonal Signature

At the core of the Monarch MKIII is THIEAUDIO’s commitment to tonal excellence. The Monarch MKIII retains a studio-monitor like tonal signature with a focused sub-bass impact for a clean, natural, and detailed sound. Engineered with a true 4-way crossover with 9 separate passive components, the Monarch MKIII stays true to its tonal legacy. Thanks to IMPACT2 , the subbass is punchier, but the mids from 200Hz to 800Hz retain their ruler-flat neutrality. This tonality of the mids mimics the true sound of studio monitors used in recording studios to deliver accurate audio reproduction.

Furthermore, compared to its predecessors, the Monarch MKIII mids have been revamped with a new tuning strategy, which better separates respective driver ranges to maximize output while minimizing the total harmonic distortion. This means the mids on the MKIII will sound higher in resolution while retaining the same monitor-esque tonality. The treble has also been slightly re-tuned to offer more coherency throughout the region, as well as little more clarity and definition. This slight tonal modification better mixes with the renewed ultra-treble response, providing a more crisp sound signature.

Thieaudio Monarch MKIII Custom Sound Signature

Medical Grade Resin Housing

Each Monarch MKIII unit is individually handmade by our dedicated engineers. The housing is constructed from 3D-printed medical-grade resin, which is safe on the skin and durable. Additionally, each faceplate of the Monarch MKIII is individually decorated and coated, presenting a truly bespoke experience.

Thieaudio Monarch MKIII Custom Resin Housing

Upgraded Modular Cable

The Monarch MKIII has been upgraded with Thieaudio’s latest modular cable. The upgraded cable is composed of thicker 22AWG 6N OCC silver-plated and graphene silver-plated composite wires. This upgrade in cable materials provides a little more clarity and refinement compared to the previous generation of Thieaudio’s modular cables. With three separate interchangeable plugs at 3.5mm single, 4.4mm balanced, and 2.5mm balanced terminations, you can easily pair the Monarch MKIII with any device, without changing cables.

Thieaudio Monarch MKIII Custom Cable


From a nameless group of DIY enthusiasts to one of the best acclaimed IEM brands in the world, THIEAUDIO has made an incredible journey in the pursuit of high-fidelity audio. THIEAUDIO has become a staple brand in audiophile communities around the world, beloved for its best-in-class tunings, superb technical performances, and budget-friendly pricing. From the start, the THIEAUDIO team has put audio quality at the forefront of each project, aiming to be the Robin Hood of the audio world by bringing the best sounding audio solutions at the most affordable prices. Since its launch in 2019, THIEAUDIO’s legacy of in-ear monitors has forever changed the world of IEM’s, influencing how global manufacturers of earphones engineer their products. THIEAUDIO’s international team of few, but dedicated engineers from China and South Korea are committed to continuing this legacy by creating innovative, yet affordable, audio solutions that will leave you in awe.

Inside the Box

  • Monarch MKIII In-Ear Monitors
  • 22AWG 6N OCC Silver-Plated and Graphene Silver-Plated Cable With Modular System
  • 3 Pairs of Silicone Ear-tips
  • 3 Pairs of Foam Ear-tips
  • Carrying Case
Thieaudio Monarch MKIII Custom In The Box

Technical Details


In-Ear Monitors


Sonion EST, Knowles DWFK 31785 (x2), Sonio 28UAP (x1), IMPACT2 (2 x 10mm Composite DD)


4-Way Passive Crossover with 4 Sound Bores.


99dB @ 1kHz (+/- 1dB)


20 ohms




1.2 meter 22AWG 6N OCC Silver-Plated and Graphene Silver-Plated Cable


2-pin 0.78mm


Modular Termination with 2.5mm,3.5mm,4.4mm Interchangeable plugs

Product Reviews