Thieaudio Monarch MkIII vs THIEAUDIO Monarch MKIV: which should you buy?

On aggregated review scores the THIEAUDIO Monarch MKIV comes out ahead with a HearWiki score of 84. The full breakdown - sub-scores, specs and what reviewers actually said - is below.

Our pick: THIEAUDIO Monarch MKIV - Outstanding overall at around $1149.

Wired IEMs

Score breakdown

Each axis is a 0–10 blend of what reviewers scored, not a lab measurement.

Neither pulls ahead overall - they trade wins across the measures.

Thieaudio Monarch MkIII
THIEAUDIO Monarch MKIV

HearWiki score

Sound

9.2

9.4

Value

7.8

7.6

Price (USD)

$1,000

$1,150

Generation & platform

The scores rank quality. This is the other question: is the newer one actually newer technology, or the same platform in a new shell?

Same generation

The THIEAUDIO Monarch MKIV is 2 years newer, but it is the same generation of hardware: nothing in the radio, the codecs or the noise cancelling separates them. Nothing separates them on convenience features either, so the choice comes down to tuning and price.

Monarch MkIII2023
Monarch MKIV20252 yr newer

Specifications

Monarch MkIIIMonarch MKIV

Type: Wired IEMs; Wired IEMs
Price (USD): $1,000; $1,150
HearWiki score: 77; 84
Released: 2023; 2025
Availability: Discontinued; Sold new
Driver: tribrid; 2DD + 6BA + 2EST tribrid
Driver type: tribrid; tribrid
Driver configuration: -; 2DD + 6BA + 2EST
Driver size: 10 mm; 8 mm
Drivers per side: -; 10
Impedance: 20 Ω; -
Active noise cancelling: No; -

Specification comparison of Thieaudio Monarch MkIII vs THIEAUDIO Monarch MKIV
Spec	Thieaudio Monarch MkIII	THIEAUDIO Monarch MKIV
Type	Wired IEMs	Wired IEMs
Price (USD)	$1,000	$1,150
HearWiki score	77 / 100 Great	84 / 100 Outstanding
Released	2023	2025
Audio
Driver	tribrid	2DD + 6BA + 2EST tribrid
Driver type	tribrid	tribrid
Driver configuration	-	2DD + 6BA + 2EST
Driver size	10 mm	8 mm
Drivers per side	-	10
Impedance	20 Ω	-
Features
Active noise cancelling	No	-

What reviewers said

Thieaudio Monarch MkIII

The Thieaudio Monarch MkIII is a wired tribrid in-ear monitor that delivers a refined, balanced sound with impressive imaging and a spacious stage. Its technical prowess and engaging tuning make it a strong contender in the premium price bracket, though its larger shells and plain aesthetic may not suit everyone.

Pro:Excellent imaging and soundstage
Pro:Rich, textured bass with good balance
Pro:Clear and resolving vocal reproduction

Con:Bulky shells may fit poorly for some
Con:Plain stock design lacks flair
Con:Not ideal for office or sport use

THIEAUDIO Monarch MKIV

The Monarch MKIV is a flagship in-ear monitor built around a ten-driver tribrid configuration, blending dual 8mm dynamic drivers, six balanced armatures, and two electrostatic tweeters. It offers a studio-neutral sound signature with an additional switchable bass-boost mode for listeners who prefer a more impactful low end.

Pro:Reference-grade neutral tuning with excellent clarity
Pro:Versatile bass boost mode adds flexibility
Pro:Detailed and extended treble from electrostatic tweeters

Con:High price point limits accessibility
Con:Requires a capable source to perform at its best
Con:Large shell may not suit smaller ears

Summaries are AI-condensed and paraphrased from published reviews and specs - not original hands-on testing. More on our method.

Compare something else

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New comparison Thieaudio Monarch MkIII THIEAUDIO Monarch MKIV