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 engineered for bass enthusiasts, offering a powerful and dominant low-end that defines its character while remaining manageable with standard portable devices. Despite its bass-forward tuning, it retains enough balance in other frequencies to stay versatile across various music genres.

Pro:Massive sub-bass impact
Pro:Easy to drive from basic sources
Pro:Bass-focused yet still versatile

Con:Bass may overwhelm some listeners
Con:No noise cancellation feature
Con:Extreme tuning not for neutral purists

THIEAUDIO Monarch MKIV

This flagship in-ear monitor packs a ten-driver hybrid setup—pairing dual 8mm dynamics with six balanced armatures and two electrostatic tweeters—to deliver a reference-grade, studio-neutral signature. It also offers a switchable RUMBLE mode for those who prefer a more pronounced low-end, catering to both purists and bass enthusiasts. The wired-only design focuses on audiophile-grade sound without active noise cancellation.

Pro:Reference-neutral tuning with optional bass boost
Pro:Layered, detailed treble from dual electrostats
Pro:Solid build and premium fit for long sessions

Con:No wireless or ANC options
Con:Large shell may not suit smaller ears
Con:Requires a quality source to shine fully

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