Hertz SPL Show ST 25A Neo.2 - 44mm Horn Tweeter for SPL Setups
The Hertz SPL Show ST 25A Neo.2 is an active horn tweeter that allows high levels and clear treble reproduction in compact installations. The drive with N38H neodymium and a FEM-calculated phase plug including horn contour ensure efficient sound conversion. The extremely lightweight aluminum diaphragm and the 25mm CCAR voice coil deliver fast transients and high reliability â ideal for loud front systems and show installations.
Technical Highlights
- Active 44mm horn tweeter without integrated crossover â for operation with an active crossover.
- N38H Neodymium magnet: high field strength in a compact design.
- FEM-optimized phase plug and horn for directed radiation and efficiency.
- CCAR voice coil (25 mm, Copper Clad Aluminum Ribbon) for high thermal and mechanical load capacity.
- Ultra-light aluminum diaphragm for high dynamics.
- High-current screw terminals for secure connection.
- Housing impregnation and anti-UV treatment for outdoor use.
- Recommended high-pass filtering: from 5 kHz with 12 dB/Oct. or steeper.
- Sensitivity: 107 dB â suitable for SPL-oriented setups.
Technical Data
- Size: 44 mm
- Power handling (Peak): 100 W
- Impedance: 4 Ohm
- Voice coil: Ă 25 mm
- Frequency response: 3 kHz â 20 kHz
- Weight: 0.39 kg
- Magnet: Neodymium
- Diaphragm: Aluminum
Electro-acoustic Specifications
- Effective diaphragm diameter (D): 35.5 mm
- DC resistance (Re): 2.9 Ohm
- Resonance frequency (Fs): 3,900 Hz
- Inductance (Le): 0.03 mH
- Force factor (Bl): 2.05 T·m
- Sensitivity (SPL): 107 dB
Dimensions
- A: 57 mm
- B: 43.5 mm
- C: 55.5 mm
- D: 29.7 mm
Installation & Compatibility
Install the ST 25A Neo.2 in A-pillar pods, mirror triangles, or custom mounts. Its compact depth facilitates installation in tight spaces. Designed purely as a tweeter, it requires active crossover â plan for a high-pass crossover from 5 kHz with 12 dB/octave (or steeper). In combination with powerful mid-range/mid-bass drivers, it creates a strong front system with high vocal and detail clarity â especially where sound pressure and precision are required.
