RAPTGO HOOK-X Planar + Piezo

The APTGO Hook-X has a hybrid in-ear monitor design utilizing the planar magnetic driver in combination with a piezoelectric (PZT) driver.

The planar magnetic driver utilizes a thin ribbon suspended between two powerful magnets through which electrical currents run. The advantage of a planar magnetic driver is the extreme responsiveness compared to dynamic or balanced armature drivers due to its lower mass and strong magnetic field. RAPTGO manufactured their own large 14.2mm planar driver, which is driven by powerful N52 magnets. Internal housing structure design and acoustic damping system were carefully brought about to achieve a balanced target tuning.

The piezoelectric driver achieves enhanced treble response through the vibration of piezo elements within the housing. In cooperation with an external team with military engineering backgrounds, RAPTGO has designed a double-sided layering system consisting of 18 ceramic piezo elements that have been fine-tuned after more than 100 acoustic shock simulation experiments. Each of the PZT drivers undergoes 52 complicated processes during production and is hand-tested and paired. In addition to the planar magnetic driver’s extended treble response, our PZT driver adds an extra dimension of sonic resolution and air that is incomparable with typical balanced armature or even electrostatic drivers.

For both tuning and acoustic properties, the Hook-X adopts an open-back design. This allows the maximum amount of airflow to highlight the planar magnetic driver’s characteristics. Additionally, this opportunity opens up the soundstage compared to typical IEMs, mimicking the openness and realistic playback of open-back planar headphones. Finally, the open-back design prevents the buildup of pressure within the ear to reduce hearing fatigue. The housing of the Hook-X was software designed after a large number of simulation experiments to match the typical ear angle and wearing experience. Each unit is crafted from a high-precision 5-axis CNC to ensure uniformity of the acoustic chambers.

The Hook-X comes standard with a modular connector cable terminated to 0.78mm 2-pin jacks. Customers can swap out the connector between the 4.4mm and 2.5mm balanced and 3.5mm unbalanced jacks.


  • Driver: 14.2mm Planar drive+Double-faced 9-layer PZT drive
  • Wear Type: In-ear
  • Sensitivity(1KHz): 105dB SPL/mW
  • Frequency range: 20Hz- 40KHz
  • Impedance(1KHz): 15Ω
  • Audio interface: 0.78mm – 2.5mm/3 5mm/4.4mm
  • Earphone cable length: 1.25m

Price: 239$