Hertz ST35ANEO 1.8" High-Efficiency Compression Driver

The Hertz ST 35A NEO is a high-efficiency compression driver designed to reproduce the upper-frequency range in custom car audio systems. Its compact 46 mm (1.8-inch) format is suited to installations that need focused high-frequency output without requiring a conventional large-format tweeter. The Active version is supplied as a tweeter-only solution for use with an appropriate external crossover or active DSP setup.

This driver is intended for enthusiasts building high-output systems where vocal detail, percussion, and treble projection need dedicated reinforcement. With a 109 dB sensitivity rating and a 2 kHz to 20 kHz frequency response, it is engineered for efficient operation in the upper midrange and high-frequency band. A 4-ohm nominal impedance supports pairing with compatible car-audio amplification channels.

The ST 35A NEO uses an extra-light aluminum diaphragm to provide a direct, crisp high-frequency presentation. Its 35 mm CCAR copper-clad aluminum ribbon voice coil is designed to handle the thermal and mechanical demands associated with high-output playback. The listed 120-watt peak rating applies when the driver is high-pass filtered at 5 kHz with a 12 dB-per-octave slope.

A neodymium motor keeps the driver compact while supporting its high sensitivity, and the horn and phase-plug geometry are FEM optimized. The aluminum rear cover aids heat dissipation during extended use. Hertz also applies waterproofing and anti-UV treatment to the body for installations exposed to changing outdoor conditions.

Use the ST 35A NEO as part of a matched multi-way system with suitable midrange drivers, amplification, and crossover control. It is a practical choice for custom doors, kick panels, rear decks, pods, and other fabricated panels where its 52 mm mounting opening can be accommodated. For serviceability, Hertz lists the VC 35 NEO replacement voice-coil assembly as available.

Key Features

• 35 mm CCAR Voice Coil: Copper-clad aluminum ribbon construction supports efficient high-frequency operation.
• Neodymium Motor: Delivers strong magnetic performance in a compact driver body.
• Aluminum Diaphragm: Extra-light diaphragm material supports direct treble reproduction.
• FEM-Optimized Horn: Phase plug and horn geometry are engineered for controlled output.
• 109 dB Sensitivity: Helps the driver produce substantial output from modest amplifier power.
• Weather-Treated Body: Waterproofing and anti-UV treatment support exposed installations.

Design & Installation

The ST 35A NEO combines a neodymium magnet, aluminum diaphragm, aluminum rear cover, and CCAR voice coil in a compact bullet-style compression-driver design. Its rear cover helps dissipate heat, while the treated body is designed to resist weather exposure and UV-related discoloration. High-current screw terminals provide a secure connection point for speaker wiring.

Mount the driver in a rigid panel with a 52 mm (2.05-inch) mounting opening and allow approximately 65.7 mm (2.59 inches) of mounting depth. Because this Active version does not include an inline crossover, use an external passive network or active DSP crossover. Apply a high-pass filter at 5 kHz with a 12 dB-per-octave slope when operating at the stated peak-power condition, and observe correct polarity when wiring the pair.