Symphonium Audio Crimson 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.

Symphonium Audio Crimson
THIEAUDIO Monarch MKIV

HearWiki score

Sound

9.2

9.4

Value

7.6

Price (USD)

$1,500

$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.

Crimson2023
Monarch MKIV20252 yr newer

Specifications

CrimsonMonarch MKIV

Type: Wired IEMs; Wired IEMs
Price (USD): $1,500; $1,150
HearWiki score: 76; 84
Released: 2023; 2025
Availability: Discontinued; Sold new
Driver: balanced armature; 2DD + 6BA + 2EST tribrid
Driver type: balanced-armature; tribrid
Driver configuration: -; 2DD + 6BA + 2EST
Driver size: -; 8 mm
Drivers per side: -; 10
Impedance: 6 Ω; -
Weight: 7 g; -
Connector: 2-pin 0.78 mm; -

Specification comparison of Symphonium Audio Crimson vs THIEAUDIO Monarch MKIV
Spec	Symphonium Audio Crimson	THIEAUDIO Monarch MKIV
Type	Wired IEMs	Wired IEMs
Price (USD)	$1,500	$1,150
HearWiki score	76 / 100 Great	84 / 100 Outstanding
Released	2023	2025
Audio
Driver	balanced armature	2DD + 6BA + 2EST tribrid
Driver type	balanced-armature	tribrid
Driver configuration	-	2DD + 6BA + 2EST
Driver size	-	8 mm
Drivers per side	-	10
Impedance	6 Ω	-
Design
Weight	7 g	-
Connector	2-pin 0.78 mm	-

What reviewers said

Symphonium Audio Crimson

The Symphonium Audio Crimson is a premium all-balanced-armature IEM delivering flagship-level dynamics, resolution, and a spacious soundstage with a lively, U-shaped tuning. It offers high-energy, technical performance with strong detail retrieval and precise separation, though its low 6-ohm impedance makes it sensitive to source pairing and eartip choices. This wired, non-ANC model suits listeners seeking an engaging, controlled sound that rewards careful setup.

Pro:Excellent detail retrieval and separation
Pro:Spacious, immersive soundstage
Pro:Lively, energetic tuning with good control

Con:Very low impedance requires quality source gear
Con:Sound varies significantly with eartips
Con:Upper treble can be sharp if fit is shallow

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

Swap either side out, or start again from the picker.

New comparison Symphonium Audio Crimson THIEAUDIO Monarch MKIV