Model High-Quality SPL Subwoofer Diameter 25 cm / 10″ Power handling (RMS) 400 Watts Impedance 2x 2 Ohms Efficiency 84 dB Power recommendation 200 – 800 Watts Voice coil 50 mm / 2″ copper Cone Paper sandwich cone Max. Excursion (Xmax) 22 mm / 0.87″ Mounting diameter 232 mm / 9.13″ Mounting depth 85 mm / 3.35″ Resonance frequency (Fs) 28 Hz Damping ratio (Qts) 0.54 Equiv. air volume (Vas) 35.8 L / 1.26 cu.ft.