FATfreq Scarlet Mini 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 3 of 4 measures.

FATfreq Scarlet Mini
THIEAUDIO Monarch MKIV

HearWiki score

Sound

8.0

9.4

Value

5.5

7.6

Price (USD)

$630

$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.

Scarlet Mini2023
Monarch MKIV20252 yr newer

Specifications

Scarlet MiniMonarch MKIV

Type: Wired IEMs; Wired IEMs
Price (USD): $630; $1,150
HearWiki score: 70; 84
Released: 2023; 2025
Availability: Discontinued; Sold new
Driver: -; 2DD + 6BA + 2EST tribrid
Driver type: -; tribrid
Driver configuration: -; 2DD + 6BA + 2EST
Driver size: -; 8 mm
Drivers per side: -; 10
Impedance: 38 Ω; -
Active noise cancelling: No; -

Specification comparison of FATfreq Scarlet Mini vs THIEAUDIO Monarch MKIV
Spec	FATfreq Scarlet Mini	THIEAUDIO Monarch MKIV
Type	Wired IEMs	Wired IEMs
Price (USD)	$630	$1,150
HearWiki score	70 / 100 Good	84 / 100 Outstanding
Released	2023	2025
Audio
Driver	-	2DD + 6BA + 2EST tribrid
Driver type	-	tribrid
Driver configuration	-	2DD + 6BA + 2EST
Driver size	-	8 mm
Drivers per side	-	10
Impedance	38 Ω	-
Features
Active noise cancelling	No	-

What reviewers said

FATfreq Scarlet Mini

The FATfreq Scarlet Mini is a wired in-ear monitor tuned for bass enthusiasts, offering a powerful and dominant low-end that defines its character. Despite its extreme bass emphasis, it remains easy to drive with portable sources and keeps the rest of the frequency range usable for broader listening. This is a specialist choice for those who prioritize sub-bass impact above all else.

Pro:Massive sub-bass presence
Pro:Easy to drive from phones or DAPs
Pro:Bass-forward tuning stays musical

Con:Bass may overpower other frequencies
Con:Not for neutral or balanced listeners
Con:Requires careful tip selection for fit

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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New comparison FATfreq Scarlet Mini THIEAUDIO Monarch MKIV