Overview

The THIEAUDIO Monarch MKII represents the company’s flagship tribrid in-ear monitor, featuring a sophisticated 1DD+6BA+2EST driver configuration [5]. This second-generation model incorporates significant technical improvements including a new composite diaphragm 10mm dynamic driver, six Knowles balanced armature drivers (doubled from the original), and two Sonion electrostatic drivers with redesigned placement to minimize tubing resonance. The Monarch MKII targets professional studio monitoring applications with measurement-based tuning and includes a proprietary Smart Switch modular cable system supporting multiple terminations.

Scientific Validity

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The Monarch MKII provides measurable technical specifications with frequency response measurements available from multiple third-party sources including Crinacle’s database using ITU-T P.57 Type 4.3 standards [1]. Independent measurements confirm ruler-flat neutrality in the critical 200Hz-1kHz midrange region with ±1dB deviation, meeting good frequency response criteria for headphones/earphones. Sensitivity of 107dB/mW meets sufficient thresholds according to measurement criteria. However, comprehensive third-party measurements for THD, SNR, dynamic range, and crosstalk specifications remain limited, with manufacturer claims of reduced distortion through doubled mid-frequency BA drivers unverified by independent testing. Conservative scoring applies due to insufficient independent measurement data to confirm transparent level performance across all critical audio specifications.

Technology Level

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The Monarch MKII demonstrates advanced technical implementation through proprietary EST integration and sophisticated 5-way crossover design. Key innovations include the Smart Switch modular plug technology allowing 3.5mm/2.5mm/4.4mm terminations, custom composite diaphragm 10mm dynamic driver with enhanced membrane tension and magnet strength, and optimized Sonion electrostatic driver placement to minimize tubing resonance. The doubling of mid-frequency BA drivers from 2 to 4 units represents meaningful technical advancement in multi-driver integration. Advanced crossover tuning and EST technology incorporation demonstrate high accumulation of know-how that competitors would want to adopt.

Cost-Performance

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At 999 USD, the Monarch MKII faces competition from the Truthear Hexa at 79.99 USD [4]. The Hexa provides equivalent-or-better user-facing functionality with 1DD+2BA configuration, 2-pin connectors, high sensitivity of 120dB/Vrms, extended frequency response coverage of 8Hz-40kHz, impedance of 20.5Ω, and THD specifications of 1% or below. Both products achieve equivalent functionality with dynamic and balanced armature drivers providing comprehensive frequency coverage and practical-level THD performance for practical use. CP = 79.99 USD ÷ 999 USD = 0.1.

Reliability & Support

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THIEAUDIO provides standard 1-year warranty coverage for the main product excluding carry cases and ear tips [2]. The tribrid design utilizes professional-grade driver units from established suppliers (Knowles, Sonion) with reduced mechanical complexity per driver type compared to single-driver solutions. Global support infrastructure includes email-based warranty claims with clear documentation procedures. The company maintains established track record with the original Monarch, though long-term reliability data for this new model remains limited.

Rationality of Design Philosophy

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THIEAUDIO demonstrates rational scientific approach with measurement-focused tuning using professional equipment and complete elimination of subjective-only approaches [3]. The company’s philosophy centers on measurement-based development with every aspect of tuning scrutinized through measurement equipment testing. The Monarch MKII shows clear progression over the original with measurable improvements including doubling of mid-frequency drivers and claimed distortion reduction through technical advancement. Advanced functional integration through Smart Switch technology and latest EST driver implementation represent meaningful technical progression rather than marketing-driven features, with costs directly contributing to measurable performance improvements.

Advice

The Monarch MKII targets professional audio applications and audiophiles seeking advanced tribrid technology with studio-grade tuning. The modular cable system and extended frequency response provide practical advantages for professional use. However, potential buyers should consider that equivalent tribrid functionality is available at significantly lower cost. The purchase is justified primarily for those requiring the specific driver configuration and THIEAUDIO’s tuning expertise, particularly for professional monitoring applications where the neutral midrange characteristics provide value.

References

[1] Crinacle - ThieAudio Monarch Mk2 Frequency Response Database, https://crinacle.com/graphs/iems/thieaudio-monarch-mk2/, accessed 2025-09-20, ITU-T P.57 Type 4.3 measurement standards

[2] THIEAUDIO Terms of Service, https://www.thieaudio.com/pages/terms-of-service, accessed 2025-09-20, warranty coverage specifications

[3] THIEAUDIO About Us, https://www.thieaudio.com/pages/about-us, accessed 2025-09-20, company philosophy and design approach

[4] Truthear Hexa Product Page, https://www.truthear.com/products/hexa, accessed 2025-09-20, product specifications and pricing

[5] THIEAUDIO Monarch MKII Official Product Page, https://www.thieaudio.com/products/thieaudio-monarch-mkii, accessed 2025-09-20, official specifications and features

(2025.9.21)