Extremely compact size for explosive performance: ST 25 is the first Hertz car audio compression driver specifically designed for SPL competitions. The 25 mm ST 25 with CCAR (Copper Clad Aluminium Ribbon) voice coil features an extra-light aluminium membrane with high thermal dissipation. An extremely powerful neodymium magnet is employed along with a highly efficient compression loading horn, designed for maximum high frequency acoustic pressure.
Data table
| Size mm (in.) | 25 (1) |
| Power Handling - Peak W | 100 |
| Impedance Ω | 4 |
| Frequency response Hz | 3k ÷ 20k |
| Sensitivity dB SPL | 107 |
| Voice coil Ø mm (in.) | 25 (1) |
| Magnet | Neodymium |
| Cone/Dome | Aluminium |
