Wired IEMs
CrinEar Project Monolith
76Great
Price n/a
Full review dataCrinEar Project Monolith 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
THIEAUDIO Monarch MKIV
84Outstanding
$1,150
Full review dataScore 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.
- CrinEar Project Monolith
- THIEAUDIO Monarch MKIV
HearWiki score
76
84
Sound
8.0
9.4
Value
6.0
7.6
Price (USD)
-
$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
CrinEar Project Monolith (2026) against THIEAUDIO Monarch MKIV (2025). These are 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.
- Project Monolith20261 yr newer
- Monarch MKIV2025
Specifications
Project MonolithMonarch MKIV
- Type
- Wired IEMs
- Wired IEMs
- Price (USD)
- -
- $1,150
- HearWiki score
- 76
- 84
- Released
- 2026
- 2025
- Availability
- Sold new
- Sold new
- Driver
- 2-driver hybrid
- 2DD + 6BA + 2EST tribrid
- Driver type
- hybrid
- tribrid
- Driver configuration
- -
- 2DD + 6BA + 2EST
- Driver size
- 10 mm
- 8 mm
- Drivers per side
- 2
- 10
- Frequency response
- 2 Hz - 38 kHz
- -
- Sound signature
- bass-heavy
- -
- Impedance
- 14 Ω
- -
- Sensitivity
- 98 dB/mW
- -
- Weight
- 16 g
- -
- Connector
- 4.4 mm balanced
- -
What reviewers said
CrinEar Project Monolith
This wired in-ear monitor showcases a bass-forward tuning with impactful low-end punch while keeping vocals and treble realistic, making it a niche choice for bass lovers rather than a universal pick. Its engineering stands out through a brass build and custom dual drivers, but with only 999 units made, finding one means scouring the secondhand market.
- Pro:Deep, powerful bass response
- Pro:Natural mids and highs despite bass focus
- Pro:Innovative brass shell construction
- Con:Bass-heavy tuning not for everyone
- Con:Very limited production run
- Con:Only available used due to 2026 release
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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