HiFiGo TRN BAX Four-Unit Flagship Headphones: A Flagship Quad-Driver Hybrid Earphone with Stunning Electrostatic Performance

Published on May 30, 2023, 12:23 p.m.

The HiFiGo TRN BAX is an exciting new flagship in-ear monitor that combines electrostatic, balanced armature, and dynamic drivers for stunning audio performance. As TRN’s first electrostatic hybrid earphone, the BAX aims to deliver unparalleled clarity and detail across an extremely wide frequency range.
 HiFiGo TRN BAX Four-Unit Flagship Headphones


The HiFiGo TRN BAX Four-Unit Flagship Headphones utilizes a quad-driver configuration consisting of two electrostatic tweeters, a Knowles balanced armature handling mids, and a 10mm dual-magnet dynamic driver for the low end. This advanced hybrid driver design allows the BAX to excel in transparency, soundstage, and resolution while maintaining powerful yet accurate bass.

Key Features:

  • Quad-driver hybrid configuration with dual electrostatic tweeters for pristine treble
  • Customized Knowles balanced armature for full, sweet mids
  • 10mm dual-magnet dynamic driver delivers impactful yet accurate bass
  • Semi-open design for pressure relief and reduced distortion

Electrostatic Performance

The two electrostatic tweeters are the real highlight, providing silky smooth and airy treble extension up to 40kHz. According to HiFiGo, the BAX exhibits better sensitivity in the 20-40kHz region compared to typical balanced armature earphones. This results in stunning realism for instruments like pianos and strings.

Customized Balanced Armature

In the midrange, HiFiGo equipped the BAX with a customized Knowles balanced armature tuned for a fuller, sweeter vocal presentation. This tailored balanced armature complements the ultra-detailed electrostatic tweeters beautifully.

Powerful Dynamic Driver

Handling the low frequencies is a capable 10mm dynamic driver featuring a dual-magnet circuit design. It provides impactful yet controlled bass to balance out the BAX’s airy top end.

Semi-Open Design

The included semi-open balanced pressure relief ear tips help optimize the performance of the hybrid driver configuration by alleviating air pressure issues inside the ear canal. This enhances clarity and reduces distortion for fatigue-free listening.

Early Expectations

While the HiFiGo TRN BAX Four-Unit Flagship Headphones has yet to be formally reviewed, its impressive hybrid driver technology and electrostatic tweeters set high expectations for sound quality. This could be an endgame IEM for critical listening and audiophiles seeking the ultimate in high-frequency detail and sparkling treble extension.

Ideal Usage Scenarios:

With its excellent noise isolation and detailed sound, the HiFiGo TRN BAX Four-Unit Flagship Headphones is ideal for critical listening in quiet environments. The semi-open design also makes it comfortable for prolonged listening sessions. Thanks to the detachable cable, the BAX can be used for sports and exercise with an appropriate replacement cable. The slick metal housing also gives it an aesthetic edge for everyday use.

User Feedback Analysis:

As the HiFiGo TRN BAX Four-Unit Flagship Headphones has just been released, there are no user reviews yet. Initial professional impressions are very positive about the electrostatic tweeters’ performance. Most hype seems to surround the BAX’s treble quality which audiophiles anticipate will set a new benchmark at this price point. Potential downsides based on the hybrid configuration could be a brighter overall tuning and slightly less mid-bass impact than single DD designs.

Pros and Cons:

- Outstanding treble extension and airiness from electrostatic drivers
- Very wide frequency response for ultra-detailed sound
- Knowles BA provides terrific midrange clarity
- Quality metal construction

- Brighter tuning not suited for treble-sensitive listeners
- Noisier isolation than closed-back designs
- Unknown how coherent the 4 drivers blend together


At around $300, the HiFiGo TRN BAX Four-Unit Flagship Headphones is very competitively priced for a quad-driver hybrid featuring exotic electrostatic tweeters. If the tuning and cohesion live up to expectations, it should represent excellent value for audiophiles. More budget-conscious buyers may want to wait for reviews before jumping on this new electrostatic model though.


  • Brand: TRN
  • Model: TRN-BAX
  • Transducer type: Quad- driver hybrid
  • Frequency response: 7Hz- 40000Hz
  • Impedance: 22Ω
  • Sensitivity: 118dB
  • Cable length: 1.2m + 3cm
  • Colors: Silver

Box Contents:

The HiFiGo TRN BAX Four-Unit Flagship Headphones includes:

  • 16 strands of silver-plated cables
  • Aluminum storage case
  • 3 pairs of Balanced ear tips
HiFiGo TRN BAX Four-Unit Flagship Headphones