Xceptional Sound Quality
New generation hybrid drivers
Swappable tuning nozzles
Aluminum alloy + resin combination
Uses standard 6N OCC copper wire
TRN STM 1DD+1BA  In-ear EarphoneTRN STM 1DD+1BA  In-ear Earphone

Hybrid technology, fine-tuned by YOU!

Ascends your listening pleasure to the next level
TRN STM comes equipped with 10mm dual magnet dynamic drivers for deep bass. Coupled with customized 30019 balanced armature drivers for mid and high frequencies, it resulted in clear treble, deep bass, rich mid-tones, and crisp vocals.
TRN STM Blue with cable

Three interchangeable color-coded tuning nozzles

Self-customization for your listening preferences
TRN STM is supplied with three tuning filters that can alter the sound. Users can customize their preferred tonality by replacing the nozzles with a different color.
TRN STM with color-coded tuning nozzles
TRN STM Yellow nozzle
Balanced and natural sound
TRN STM Red nozzle
Deep bass, fast transient
TRN STM Blue nozzle
Resolving treble

Vibrant Blue

Lush Green
TRN STM is available in Blue and Green. Different colors and choices to meet individual needs.
TRN STM Blue and green

Hybrid configurations give a vivid and delightful music experience

Professionally tuned by TRN's engineers using customized 30019 balanced armature and 10mm dynamic driver, TRN STM presents a vibrant yet comfortable sound that is non-fatiguing thus suitable for extended listening.
10mm dual magnet dynamic driver
30019 balanced armature driver
Interchangeable color-coded nozzles
TRN STM scheme

10mm dual magnet dynamic driver

TRN STM comes equipped with dual magnet dynamic drivers. Dual magnet gives higher magnetic flux, which gives high sensitivity and low impedance increases energy efficiency and transient response.
10mm dual magnet dynamic driver

Customized 30019 balanced armature drivers for better resolution and fidelity

TRN STM utilizes customized 30019 balanced armature drivers for a clear and open treble extension. Balanced armature uses "armature + drive rod" that reproduces high-frequencies that diaphragm-based dynamic driver could not achieve and give faithful sound reproduction without losing micro details.
Customized 30019 balanced armature driver

The high-quality alloy housing plate

Aluminum alloy front plate combines with resin housing for rigidity and toughness.
TRN STM Blue without cable

Electronic crossover for exceptional sound quality throughout the entire frequency band

Exquisitely designed electronic crossover unleashes the full potential of every driver unit, both the balanced armature driver and dynamic driver, giving utmost sound quality across the frequency band.
TRN STM internal structure

Sharply-focused and insistent on using better technology and professional tuning

The frequency response is smooth and coherent. Rich in vocal texture with a balance of harmony in every subtle nuance. Optimal bass reproduction with an effortless transient attack, precision, and low distortion.
TRN STM frequency response
*The above data is from TRN Acoustic Laboratory Test. Actual use may be slightly different.

Ergonomically-designed ear hooks

Over-the-ear ear hooks for maximum comfort and stability allow you to focus on your music while performing daily activities. At the same time, such wearing method reduces microphonics transmit to the earpieces, thus less interference to your music enjoyment.
TRN STM in a man's ear with closed eyes

Newly improved 0.75mm Type-C connectors

Gold-plated contact pins
From reviews and customers feedback, it is known that the new and improved Type-C connectors can effectively protect the contact pins from accidental breakage, which gives longevity and better wearing stability to the users.
TRN STM Connector design

Audiophile quality 4-core high-purity OCC monocrystalline copper cable

TRN STM includes a 4-core high-purity OCC monocrystalline copper cable that enhances sound transparency, improves bass texture, and adds body to vocal.
4-core high-purity OCC monocrystalline copper cable

Wide compatible cable

HD Smart Wire Control
The omnidirectional microphone supports HD calling on mobile phones with international standard (American standard) interface formats. High-quality gold-plated 3.5mm connectors are compatible with all audio equipment with 3.5mm connectors.
TRN STM cable


Product name
Transducer type
Hybrid In-Ear Monitors
Ear hook
Jack type
Connector type
Frequency response
Weight with cable
Cable length
College blue / Verdant green

Contents & Packaging

TRN STM earphone size
TRN STM Earphone x 1 pair
6N OCC copper cable x 1 piece
Color-coded tuning nozzles x 3 pairs
Silicone ear tips (S,M,L) x 3 pairs
User guide x 1
Actual product specifications may vary, and all features, functionality, and other product specifications are subject to change without notice or obligation.
TRN STM in a man's earClose up of TRN STM in a man's earGreen TRN STM earphoneClose up of green TRN STM earphone

Attaching cable

TRN STM cable choosing scheme
Match left, and right earpieces to the correct channel stated on the cable connectors.
TRN STM cable reverse avoid scheme
DO NOT connect reverse.
TRN STM how to plug in cable scheme
Plug cable connector to the earpiece.
TRN STM how to plug in cable scheme
Insert until the earpiece is secure. To remove, grab the earpiece and cable connector, pull straight.

How to properly fit an IEM

TRN STM sketch
Identify the left and right earpieces.
How to put the TRN STM cable on your ear
Bring hand overhead and grasp the top of the ear.
How to align the TRN STM earbud in your ear
Pull the ear up and out to straighten the ear canal.
How to fix the TRN STM earphone in your ear
Loop memory wire over-ear and insert earpiece into the ear canal.
How to check if the TRN STM earbud is securely in your ear
Be sure to slide the ear tip far enough until it seals inside your ear.
The quality of sound and isolation depends on how well the ear tips seal. If lacking bass, check the tightness of the seal between ear tips and your ears or try other ear tip sizes.


Dongguan Zuodu Acoustics Technology Co., Ltd.
5tn Floor, 67 Baisha Road, Humen Town, Dongguan City, Guangdong Province
QQ: 2550039547
Phone: 400-8080-302
Monday to Sunday 8:30 am to 6:00 pm (UTC+8)