The Thieaudio Monarch MKIV is a ten-driver in-ear monitor made by Thieaudio, priced at $1,149 USD, featuring a physical tuning switch that fundamentally changes how you listen. With two dynamic drivers, six balanced armatures, and two electrostatic drivers packed into each shell, these IEMs sit firmly in the endgame category—but not without caveats.
Key Takeaways
- Ten drivers per shell (2 DD, 6 BA, 2 EST) with new 8mm IMPACT² dual dynamic drivers for improved bass delivery
- Physical 2-position tuning switch: default mode offers clean, detailed sound; bass-boost mode adds sub-bass rumble and mid-bass impact
- T6 aluminum shells represent a step up from previous resin construction, matching flagship Valhalla’s metal design
- Priced at $1,149—hundreds less than Thieaudio’s V16 Divinity and Valhalla flagships
- All-rounder tuning handles hip-hop, rock, classical, and vocals without specializing in any single genre
What Makes Thieaudio Monarch MKIV Different
The Thieaudio Monarch MKIV improves on its predecessor with more sub-bass rumble, smoother treble, and refined layering that makes a real difference in daily listening. The headline upgrade is the physical tuning switch—a robust, satisfying click mechanism that toggles between a clean, detailed default mode and a bass-boosted presentation without muddying the mix.
This isn’t a subtle EQ tweak. In default mode, you get cleaner, airier sound with more detail and precision. Flip the switch, and sub-bass rumble emerges alongside mid-bass impact, note weight, and a fuller low-end that works for warmer, harder-hitting music without bloat. The ability to physically switch between tunings without an app or software feels refreshingly tactile in an era of digital solutions.
The T6 aluminum shells share a sculpted metal design with Thieaudio’s flagship Valhalla, though the faceplate here is less visually striking. The modular cable included carries forward a feature from earlier Monarch iterations, giving you flexibility in connectivity without forcing a proprietary ecosystem.
Thieaudio Monarch MKIV vs. Flagship Competitors
At $1,149, the Monarch MKIV costs hundreds less than the V16 Divinity and Valhalla, yet reviewers do not recommend it as a clear upgrade from those flagships in blind listening tests. The Valhalla retains the best technical ability and perceived imaging in Thieaudio’s lineup, while the V16 Divinity edges out the Monarch MKIV in subjective enjoyment at CanJam SoCal demos.
The practical reality: the Monarch MKIV is the most versatile all-rounder Thieaudio currently sells. If you want a single IEM that truly handles everything—rumbling sub-bass with modern hip-hop, warm bass presentation in classic rock, tight precise separation with classical music and film scores, plus solid vocal performance—the Monarch MKIV specializes in not specializing. Compared to the more niche Oracle MKIII, which emphasizes refined bass layering and subtle mid-bass emphasis, the Monarch MKIV offers broader genre coverage without sacrificing technical ability.
Does Bass Boost Mode Actually Work?
The bass-boost tuning switch is the Monarch MKIV’s signature feature, yet its impact is subtle rather than transformative. Thieaudio’s new 8mm IMPACT² dual dynamic drivers deliver improved bass compared to the MKIII, but the switch does not create two radically different listening experiences—it shifts emphasis, not personality.
For listeners who want flexibility without buying multiple IEMs, this is valuable. For those seeking a bass-focused monster or a clinical reference monitor, the Monarch MKIV lands somewhere in the middle, doing both competently but specializing in neither. The EST drivers contribute natural timbre across both modes, preventing the bass boost from feeling artificial or fatiguing even during extended listening sessions.
Who Should Buy the Thieaudio Monarch MKIV?
Reviewers recommend the Monarch MKIV as endgame for the vast majority of listeners seeking technical performance, treble refinement, and versatile all-rounder tuning. The comfortable fit, robust tuning switch, and refined imaging make these IEMs compelling if you stream across multiple genres and want one tool to handle everything.
You should skip the Monarch MKIV if you have already invested in Thieaudio’s flagships or if you demand specialization—a single-tuning IEM optimized for jazz or EDM rather than a compromise tuning that touches everything. The $1,149 price tag sits at the entry point of true endgame territory, where diminishing returns accelerate. You are not paying for the best technical performance Thieaudio makes; you are paying for versatility and refinement.
Are Thieaudio Monarch MKIV worth the upgrade from MKIII?
If you own the Monarch MKIII, the MKIV’s improvements in sub-bass, treble smoothness, and refined layering justify the upgrade only if you value the physical tuning switch and aluminum shells. The core tuning philosophy remains similar, so the jump is iterative rather than revolutionary.
How do the Monarch MKIV compare to other $1,000+ IEMs?
At this price point, the Monarch MKIV faces stiff competition from Thieaudio’s own V16 Divinity and Valhalla. The Valhalla offers better technical imaging, while the V16 Divinity delivers more subjectively engaging sound. The Monarch MKIV wins on versatility and value, not on raw technical prowess.
Can you swap cables on the Thieaudio Monarch MKIV?
Yes. The Monarch MKIV includes a modular cable, allowing you to swap connectors and experiment with different cable materials without replacing the entire IEM.
The Thieaudio Monarch MKIV is a genuinely strong all-rounder that earns its endgame positioning through versatility and refinement rather than technical supremacy. The physical tuning switch is the real story here—not because it transforms the IEMs into two completely different monitors, but because it gives you control without apps, software, or multiple purchases. At $1,149, you are getting a competent, comfortable, refined IEM that handles everything competently. That is not hype. That is exactly what most listeners actually need.
Edited by the All Things Geek team.
Source: Android Central
