64 Audio U12t 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.

THIEAUDIO Monarch MKIV leads on 4 of 4 measures.

64 Audio U12t
THIEAUDIO Monarch MKIV

HearWiki score

Sound

9.2

9.4

Value

6.4

7.6

Price (USD)

$2,000

$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 7 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. For 7 years between them, that is a thin return - treat this as a restyle rather than a new platform.

U12t2018
Monarch MKIV20257 yr newer

Specifications

U12tMonarch MKIV

Type: Wired IEMs; Wired IEMs
Price (USD): $2,000; $1,150
HearWiki score: 72; 84
Released: 2018; 2025
Availability: Discontinued; Sold new
Driver: 12BA; 2DD + 6BA + 2EST tribrid
Driver type: balanced-armature; tribrid
Driver configuration: 12BA; 2DD + 6BA + 2EST
Driver size: -; 8 mm
Drivers per side: 12; 10
Impedance: 12.6 Ω; -
Sensitivity: 108 dB/mW; -
Active noise cancelling: No; -
Connector: 2-pin 0.78 mm; -

Specification comparison of 64 Audio U12t vs THIEAUDIO Monarch MKIV
Spec	64 Audio U12t	THIEAUDIO Monarch MKIV
Type	Wired IEMs	Wired IEMs
Price (USD)	$2,000	$1,150
HearWiki score	72 / 100 Great	84 / 100 Outstanding
Released	2018	2025
Audio
Driver	12BA	2DD + 6BA + 2EST tribrid
Driver type	balanced-armature	tribrid
Driver configuration	12BA	2DD + 6BA + 2EST
Driver size	-	8 mm
Drivers per side	12	10
Impedance	12.6 Ω	-
Sensitivity	108 dB/mW	-
Features
Active noise cancelling	No	-
Design
Connector	2-pin 0.78 mm	-

What reviewers said

64 Audio U12t

The 64 Audio U12t is a flagship 12-driver balanced-armature in-ear monitor that delivers a transparent, neutral midrange with powerful lows and airy highs. Its exceptional resolution, precise imaging, and spacious soundstage make it a technical benchmark in its class, while swappable APEX modules offer tuning flexibility. Priced at around $2000, it's a premium wired IEM with no active noise cancellation, aimed at audiophiles seeking an immersive, detailed listening experience.

Pro:Excellent transparency and neutral balance
Pro:Powerful, extended bass with strong quality
Pro:Spacious three-dimensional soundstage

Con:Very expensive price point
Con:Minor treble quirks noted
Con:Requires a good source to perform fully

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.

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