In-Ear MonitorOverreview

TRN Mermaid

TRN's first $200 flagship pairs a glass-dome woofer, a Knowles armature and two planars — and reviewers can't agree whether that adds up to a warm, smooth vocal set or a lively V with a sharp 8 kHz edge.

29 sourcesUpdated
$199.99Typical US price

Score aggregates reviewer opinions across topics.

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TRN Mermaid

The short version

What to know.

The TRN Mermaid is a four-driver tribrid — one dynamic, one balanced armature, two planar — sold for $199.99 ($229.99 in green). Three measurement rigs agree on a bass shelf at the Harman level with 3–4 dB extra around 100–200 Hz, an early ear-gain peak near 2 kHz, a deep 4–7 kHz dip and a sharp peak around 8 kHz. Reviewers broadly agree on clear, present vocals with good body; detail and separation that impress for the price; bass with plenty of weight that is mostly well controlled; and a comfortable, distinctive shell — with the flat stock cable the common complaint. Opinion splits five ways. Overall balance reads as warm and smooth to most, but as a lively, bright-edged V to a technical minority. The treble is smooth and fatigue-free to most listeners, while others hear the 8 kHz peak as incisive or tiring. The soundstage is wide to half the sources and only average to the other half. Dynamics are energetic to some and gentle to others. And at roughly $200–300 it is fair value to some reviewers and overpriced next to TRN's own cheaper sets to others.

About this product

TRN's 2025 flagship of its ocean-themed range: a 10 mm glass-dome dynamic driver, one Knowles 33518 balanced armature and two 6 mm planar drivers per side. Sold in Ink Night Purple ($199.99) and Jade Shadow Green ($229.99), with one cable terminated in 3.5 mm or 4.4 mm, chosen at purchase. Not the CVJ x R2E3 Mermaid II from TRN's sister brand.

TRN made its name with cheap multi-driver sets; the Mermaid, released at the end of 2025 as the top of its ocean-themed line, is its move into the $200 class. Each scaled, fin-tipped shell holds a 10 mm dynamic driver with a glass-dome diaphragm, a Knowles 33518 balanced armature and two 6 mm planar drivers, tuned, TRN says, with female vocals in mind.

Most of its coverage comes from Japanese bloggers, Russian YouTube and a handful of English Reddit reviewers, nearly all on units TRN supplied. They largely agree on the vocals, the detail and the finish. They split on almost everything that defines its character: whether it is warm or bright, smooth or incisive up top, wide or ordinary in space, and whether it is worth flagship money from TRN.

A good fit for

  • Listeners who want vocal-centred, warm-leaning sound with detail
  • Acoustic, orchestral and vocal music where timbre and separation matter
  • Buyers who value a distinctive shell design and a full box of tips

Think twice if

  • Treble-sensitive listeners — the 8 kHz peak bothers some
  • Bassheads or anyone after hard-hitting tribrid slam
  • Buyers who want a modular or easy-handling stock cable
  • Shoppers paying a $250–300 street price — reviewers who did were the least convinced

The reviewer consensus

Agreement &
disagreement.

5 / 11topics divide opinion
bassmidsimagingdetailcomfortbuildtonalitytreblesoundstagedynamicsvalue
6 Mostly agree5 Divided opinions

Common ground5

  • Clear, present vocals with body — the most praised region
  • Detail and separation above its price, without an etched edge
  • Weighty, mostly well-controlled bass with a warm mid-bass lift

Points of contention5

  • Tonality: warm and smooth vs a lively, bright-edged V — the curve has both a warm lift and an 8 kHz peak
  • Treble: fatigue-free vs an incisive 8 kHz peak for treble-sensitive listeners
  • Soundstage: wide and enveloping vs average for the price (and narrower on fast rock and pop)

A closer listen.

11 topics · 5 divided
Left: criticalRight: positiveTighter lines: more agreement

Tonality

Leans positiveDivided opinions
Reviewer sentiment18 supporting sources
CriticalNeutralPositive

Band: opinion spread · Dot: weighted average

Sources split: most describe a warm, smooth, gently V- or U-shaped listening tune centred on vocals; a technical minority (SyncerTech, Hwee Hi-Fi, HiFijuegos) hears an energetic, clean, bright-edged V that trades weight and evenness for sparkle. Both camps describe the same curve — a warm 100–200 Hz lift and a recessed 4–7 kHz region next to an 8 kHz peak — weighting different octaves.

Measured

Against Harman IE 2019 on three squig rigs (500 Hz normalised): 20 Hz within ±0.5 dB, 100–200 Hz 3–4 dB over, ear gain peaking early near 2 kHz, 4–7 kHz 5–10 dB under, and an 8 kHz peak 1.5–7 dB over the target.

vs. listeners — The graph supports both readings: the upper-bass lift and the deep 4–7 kHz dip make it sound warm and relaxed, while the isolated 8 kHz peak gives the sparkle and edge the bright camp hears.

Where it splits
Warm and smooth — a relaxed, vocal-centred listening tune that never turns harsh.71%

“全体的な音色として、私自身のイメージは「やや暖色寄り～ニュートラル」だと感じました。”

Uni Sonia (Japanese: “Overall, my impression of the tone is ‘slightly warm to neutral’”)
Lively and bright-edged — a clean, energetic V/U-shape built for effect rather than evenness.29%

“Модель ориентирована на эффектное, а не на ровное звучание, поэтому и такая настройка.”

SyncerTech, iXBT Live (Russian: “The model is aimed at an effective rather than an even sound, hence this tuning”)
Link to this topic

The hardware

Specifications.

Checked

Design

Type
In-ear monitor
Drivers
1 × 10 mm dynamic (Glass Diaphragm dual Magnetic Dynamic Driver) + 1 × balanced armature (33518 Knowles Electronics Balanced Armature) + 2 × 6 mm planar magnetic (titanium-coated diaphragms)1DD + 1BA + 2Planar

Electrical

Impedance
32 Ω
Sensitivity
109 dB/mW≈ 123.9 dB/V
Frequency response
10 Hz – 40 kHz

Connection

Cable
Detachable, 1.2 m
Connector
0.78 mm 2-pin
Plugs supplied
3.5 mm, 4.4 mm balanced

Ships with one cable, terminated in either 3.5 mm or 4.4 mm — chosen at purchase. Manufacturer-published figures, not measurements · from trn-audio.com.

Follow the evidence

Sources 29

1–6 of 29 sources

Read with context

Limitations & method.

As of

What to keep in mind 5

  1. A read of where the reviews land as of October 2026, ten months after launch — the $200 hybrid field around it keeps moving.

  2. Nearly every published review was written on a unit TRN supplied or lent, and much of the coverage is in Japanese and Russian; owners' own reports are still few.

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