TRN Shell Review 

 

Introduction:

TRN, a well-established Chinese Hi-Fi brand based in Dongguan City, Guangdong Province, has built a reputation for delivering high-value portable audio products, including earphones, Bluetooth devices, cables, and accessories. The company continues to innovate with its latest release, the TRN Shell. This In-Ear Monitors features a unique quad-driver hybrid configuration, incorporating a 10.5mm beryllium-plated dynamic driver, an 8mm PET diaphragm dynamic driver, a 6mm titanium-plated dynamic driver, and a 6mm planar diaphragm driver unit. Inspired by the aesthetic of seashells, the TRN Shell aims to blend style, comfort, and a lively sound profile at an accessible price point.

 

Disclaimer:

I would like to thank Shenzhen Audio and TRN for providing me the Shell Hybrid In-Ear Monitor as review sample. I am not affiliated with Shenzhen Audio and TRN or any third person beyond this review and all these words reflect my true, unaltered opinions about the product.

 

Price & Availability:

The TRN Shell is priced at approximately $59.99 USD, making it a compelling option in the budget IEM market. For the latest pricing and availability, check the official product page:

• TRN Shell Hybrid IEM

 

Package and Accessories:

The TRN Shell arrives in a rectangular box that is predominantly black, featuring a image of a glowing blue shell at the center. The text “SHELL” is displayed in bold, uppercase letters in a golden color.

This box includes the following contents;

• 1 pair x TRN Shell Hybrid In-Ear Monitors
• 1x 4-strand Silver-Plated Hybrid Cable (Oxygen-Free Copper and Silver) with Swappable Termination Plugs
• 1x Earphone Carrying Case
• 3x Swappable Tuning Nozzles (Black, Green, and Red rings)
• 2x Modular Termination Plugs (1x 3.5mm Single-Ended, 1x 4.4mm Balanced)
• 13x pairs of Ear Tips (3x pairs Liquid Transparent Ear Tips [S, M, L]
• 3x pairs Silicone Tips [S, M, L]
• 3x pairs White Silicone Tips [S, M, L]
• 3x pairs T Tips [S, M, L], 1x pair Memory Foam Ear Tips [M]
• 1x User Manual and Quick Start Guide

The inclusion of a wide variety of ear tips, swappable nozzles, interchangeable termination plugs, and a carrying case enhances customization and portability, allowing users to tailor the sound, fit, and connectivity to their preferences.

 

Design & Build Quality:

The TRN Shell stands out with its sleek, modern design, drawing inspiration from the organic curves of seashells. The ear shells are crafted from high-quality liquid metal alloy, finished with a premium electroplating process that gives them a polished, mirror-like appearance. The all-metal construction adds a bit of weight to the shells, but they remain comfortable for extended wear due to their ergonomic shape. However, the glossy finish makes the Shell slightly prone to fingerprints and scratches, so extra care is recommended during handling.

The front of each monitor features a striking faceplate design that mirrors the natural flow of a seashell’s curves. The surface showcases smooth, wave-like patterns that ripple across the shell, creating a mesmerizing, almost liquid-metal effect under light. Unlike earlier impressions, the TRN logo is not present on the faceplate, allowing the organic, flowing design to take center stage and enhance the IEM’s sophisticated aesthetic.

The rear of the shell continues the liquid metal construction, maintaining the seamless seashell-inspired curvature. This area is free of any markings or features, contributing to the overall clean and modern look of the IEM while emphasizing its minimalist design philosophy.

On the top of each shell, regular 0.78mm 2-pin connectors ensure a secure connection with the included cable. This section also includes the TRN branding, L/R markings, and a small acoustic opening for pressure relief, all neatly positioned near the 2-pin connector interface for a functional yet unobtrusive design.

The inner surface includes a slightly angled nozzle for a secure fit, paired with a gold-plated brass mesh filter to prevent debris from entering the driver chamber. The nozzles are swappable, with three distinct options (black for transparent sound, green for reference tuning, and red for an atmospheric profile), each marked by a colored ring for easy identification.

The TRN Shell arrives with a 4-strand silver-plated hybrid detachable cable, combining 89-core high-purity oxygen-free copper and silver-plated litz braided strands for improved conductivity and reduced signal distortion.

It features a soft, transparent insulation and flexible heat-shrink ear guides for comfort during extended use.

The cable’s swappable termination plug system includes 3.5mm single-ended and 4.4mm balanced plugs, housed in robust metal casings with clear Blue (Left) / Red (Right) markings.

The build quality is exceptional for the price, with the liquid metal shells feeling robust, sturdy, and durable while maintaining a pure sound resonance. The streamlined seashell-inspired design is both simple and modern, making the Shell a beautifully crafted IEM.

 

Comfort & Isolation:

The TRN Shell’s compact shell design makes it surprisingly comfortable, even for a quad-driver IEM. The smooth, curved inner surface fits snugly in the ear without causing pressure points, though users with smaller ears may notice a slight suspension of the shell. The all-metal construction adds a bit of weight, but the ergonomic shape ensures it remains comfortable for extended listening sessions. The medium-sized nozzle accommodates various ear tips, and the included liquid silicone tips provide a secure seal. While comfortable for extended listening at home, the weight of the metal shells makes them less ideal for activities like jogging. Passive noise isolation is average, effectively blocking moderate ambient noise in environments like cafes or public transport. The inclusion of a small pressure relief vent helps balance internal air pressure, reducing fatigue during long sessions, but it slightly compromises isolation compared to fully sealed designs.

 

Technical Specifications:

• Driver Configuration: 10.5mm Beryllium-Plated Dynamic Driver + 8mm PET Diaphragm Dynamic Driver + 6mm Titanium-Plated Dynamic Driver + 6mm Planar Diaphragm Driver
• Frequency Response: 20Hz-20kHz
• Sensitivity: 110dB
• Impedance: 16Ω
• Cable Material: 4-strand Silver-Plated Hybrid (89-core Oxygen-Free Copper and Silver-Plated Litz Braided)
• Connector Type: 0.78mm 2-Pin
• Termination Plugs: 3.5mm Single-Ended + 4.4mm Balanced
• Cable Length: 1.2m

 

Drivability & Pairing:

With an impedance of 16 ohms and a sensitivity of 110dB, the TRN Shell is highly efficient and easy to drive. It pairs well with a variety of sources, from smartphones and tablets to dedicated DAPs and DAC/amps. Testing with devices like the HiBy R6 III 2025 and FiiO KA17 revealed that the Shell scales well with higher-quality sources, offering improved dynamics and clarity, but it still delivers a satisfying experience with basic setups.

Sources used for this review: 

• IEM                 : TRN Shell, TRN ST5
• DAP/DAC      : HiBy R6 III 2025, FiiO KA17 

 

Albums & tracks used for this review:

• Norah Jones – Come Away With Me (Apple Music Lossless)
• Adele – My Little Love (Apple Music Lossless)
• Sarah McLachlan – Angel (Flac 24bit/48kHz)
• Sertap Erener – Aşk (Flac 16bit/44.1kHz)
• Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
• Diana Krall – So Wonderful (DSF)
• Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
• Michael Jackson – Billie Jean (Flac 24bit/96kHz)
• George Michael – Don’t Let the Sun Go Down on Me (Flac 24bit/192kHz)
• David Bowie – Heroes (Flac 24bit/192kHz)
• Elton John – Rocket Man ((Flac 24bit/96kHz)
• Barry White – Just The Way You Are (Flac 24bit/48kHz)
• Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
• Sting – Englishman in New York – (Flac 24bit/48kHz)
• Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
• Dave Gahan – Kingdom (Tidal Hi-Fi)
• Radiohead – Live in Berlin “Album” (Apple Music Lossless)
• Radiohead – Pyramid Song (Apple Music Lossless)
• U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
• Muse – Hysteria (Flac 24bit/96kHz)
• Red Hot Chili Peppers – Nobody Weird Like Me (Flac 24bit/48kHz)
• Michael Jackson – Billie Jean (Flac 24bit/96kHz)
• Bear McCreary’s – Valkyries (Deezer HiFi)
• Bro Safari, UFO! – Drama (Deezer HiFi)
• Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
• Daft Punk – Instant Crush (Flac 24bit/96kHz)
• Daft Punk – Doin’ it Right (Flac 24bit/96kHz)
• Lorde – Royals (Flac 24bit/48kHz)
• Massive Attack – Angel (Flac 24bit/48kHz)
• Toutant – Rebirth (Deezer HiFi)
• Gogo Penguin – Raven (Flac 24bit/192kHz)
• Gogo Penguin – Murmuration (Flac 24bit/192kHz)
• Portishead – It Could Be Sweet (Apple Music Lossless)
• Hans Zimmer – The Dark Knight OST (Flac 24bit/96kHz)
• Max Richter – On the Nature of Daylight (Flac 24bit/96kHz)
• Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
• Tchaikovsky – Symphony No. 5 (Flac 16bit/44.1kHz)
• Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
• Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
• Clair de Lune – Claude Debussy (Spotify)
• Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
• Vivaldi – Le QuarttroStagioni “The Four Season” (Apple Music Lossless)
• Pink Floyd – Shine On You Crazy Diamond (Apple Music Lossless)
• Miles Davis – So What (Deezer HiFi)
• Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
• Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
• Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
• Metallica – Dyers Eve (Flac 24bit/96kHz)
• Metallica – Sad but True (Flac 24bit/96kHz)
• Opeth – Windowpane (Flac 16bit/44.1kHz)
• Megadeth – Sweating Bullets (Tidal Hi-Fi)
• Rush’s – Tom Sawyer (Flac 16bit/44.1kHz)
• Slayer – Angel of Death (Spotify)
• Liquid Tension Experiment 2 – Acid Rain (Spotify)
• Yosi Horikawa – Bubbles (Spotify)

 

The Sound:

The TRN Shell delivers a relatively consistent tonality across the frequency spectrum, leaning towards a slightly V-shaped sound signature while also presenting a brighter-than-neutral character.

After a 50-hour burn-in period using the green-ring nozzle, transparent silicone ear tips, and the stock cable, the Shell offers a firm and fast sound profile that maintains a balanced presentation with smooth transitions between frequency ranges. The overall tonality is smooth, with no obvious artificial coloration, ensuring a natural and unexaggerated listening experience. Let’s take a closer look at the sound profile.

 

Impact of Interchangeable Nozzles:

The TRN Shell’s swappable nozzles allow for subtle adjustments to the sound signature, offering a degree of customization to suit different preferences.

The black nozzle provides the most neutral and analytical sound, with a less emphasized bass and a more prominent treble, enhancing clarity and detail retrieval for critical listening.

The green nozzle delivers a reference tuning, striking a more balanced presentation across the frequency spectrum, making it ideal for a neutral and accurate sound.

The red nozzle introduces a slightly warmer and more atmospheric profile, with a touch more bass emphasis and a smoother treble, creating a more relaxed and immersive listening experience. These options allow users to fine-tune the Shell’s tonality, catering to a range of listening preferences while maintaining its inherent balanced yet slightly V-shaped character.

 

Bass / Midrange / Treble / Soundstage:

The bass is produced with a moderate level quantity, showing a slightly thick texture that provides a stable low-frequency foundation. It demonstrates good extension into the sub-bass region, which would allow tracks like Armin Van Buuren – Vini Vici and Lorde – Royals to convey their deep, rumbling low-end frequencies with noticeable presence.

The speed of bass note decay is moderate, which allows the intricate bass lines in Gogo Penguin – Raven to be discernible, though the ultimate sense of agility and control in the midbass is a bit tempered by the described thickness. A subtle elevation in the mid-bass frequencies can introduce a slight warmth to the lower registers of the midrange, yet the overall bass remains generally well-defined and balanced.

The midrange frequencies are characterized by a rich and warm tonality, possessing a good sense of fullness that ensures both instrumental and vocal elements are clearly positioned within the sonic mix. Female vocals, such as those in Norah Jones – Don’t Know Why, Adele – My Little Love, and Edith Piaf – Non Je Ne Regrette Rien are repoduced with a moderate level thickness and a slightly forward placement in the presentation, conveying good transparency and clarity. The perceived scale or “size” of vocal reproduction spounds a bit reduced, while male vocals, such as those in George Michael – Don’t Let the Sun Go Down on Me, David Bowie – Heroes, and Elton John – Rocket Man, should also benefit from the warm and full character of the lower midrange, though the desdo have a slight mid-bass elevation that adds a touch of extra body to these vocal performances. The overall midrange maintains a natural and lifelike quality.

The treble range displays a moderate level of brightness, contributing a sense of liveliness and enhancing the retrieval of fine details within the audio signal. The overall treble presentation remains smooth, with only minor peaks that generally avoid causing listening fatigue or harshness, which would be beneficial for the potentially aggressive high frequencies in Megadeth – Sweating Bullets, preventing them from becoming overly strident. Extension into the ultra-treble frequencies is present, although a slight roll-off at the extreme upper limits softens the very highest harmonics. Instruments occupying this frequency range are rendered with good detail and clarity. Sibilance is generally well-controlled and not a prominent issue.

The soundstage offers a balanced spatial presentation, avoiding both an overly expansive and a constricted feel. A sense of openness and airiness is present, providing both width and a degree of depth to the sonic image. While the precise delineation of instrument placement within this space is not a primary characteristic, the separation between individual sonic elements, particularly vocals and instruments, is generally well-maintained, which allows the various elements in all the listed tracks to be reasonably distinguished. The level of detail resolution is notable, and dynamic contrasts are conveyed with good impact, while the speed of transient response is average. The layering of instruments in densely orchestrated passages might exhibit some limitations in fully separating complex arrangements.

 

Comparison:

TRN Shell versus TRN ST5:

The TRN ST5, with its 4BA + 1DD configuration, offers a livelier, V-shaped sound compared to the Shell’s slightly V-shaped, brighter-leaning neutral profile. Both IEMs feature high-quality metal shells, but the Shell’s liquid metal alloy and seashell-inspired design feel more premium and modern. Both IEMs include modular cable designs, with the Shell offering 3.5mm and 4.4mm termination plugs and the ST5 providing additional 2.5mm balanced options. The Shell’s swappable nozzles provide greater sound customization compared to the ST5’s fixed tuning.

In terms of sound, the Shell delivers a more controlled bass response with a slightly thicker presentation, while the ST5 emphasizes a punchier bass. The ST5’s midrange is more transparent and airy, making it better suited for vocal clarity, while the Shell’s mids are warmer and richer, favoring genres like jazz and acoustic. The treble on the ST5 is brighter and more extended, but the Shell’s smoother treble is less fatiguing over time. Both IEMs offer comparable soundstage width, but the Shell’s balanced tonality creates a more cohesive and natural experience.

 

Conclusion:

The TRN Shell is a remarkable achievement in the budget IEM market, offering a premium build, versatile tuning options, and a balanced, slightly V-shaped sound signature for just $60.00 USD. The unique quad-driver hybrid setup, combined with swappable nozzles and a flagship-grade modular cable, delivers a level of performance and customization rarely seen at this price. While it may not compete with higher-end IEMs in terms of soundstage depth or layering in complex tracks, the Shell excels as an all-around performer for audiophiles and casual listeners alike. Its elegant design, robust build, and comfortable fit further solidify its value, making it a standout choice in 2025’s competitive IEM landscape.

 

Pros & Cons:

• + Balanced, slightly V-shaped sound signature with a smooth, natural tonality
• + Premium liquid metal shell featuring a stylish, seashell-inspired design
• + Swappable nozzles and termination plugs for customization
• + Comfortable fit suitable for extended listening sessions
• + Comes with a comprehensive set of accessories
• + Exceptional value for its price point

 

• – Layering can feel limited in complex musical tracks
• – The glossy finish is prone to fingerprints and scratches
• – The all-metal shell is robust but somewhat heavier

 

Thank you for the Read!