Model: High-Quality Flat SPL Subwoofer Diameter: 20 cm / 8″ Power handling (RMS/SPL): 500 / 800 Watts Impedance: 2x 2 Ohms Efficiency: 83 dB Power recommendation: 350 – 800 Watts Voice coil: 63 mm / 2.5″ Copper Cone: Sandwich paper Max. Excursion (Xmax): 24 mm / 0.94″ Mounting Ø: 187 mm / 7.36″ Mounting depth: 80 mm / 3.15″ Resonance frequency (Fs): 31.5 Hz Overall quality (Qts): 0.41 Equiv. air volume (Vas): 14.2 L / 0.50 ft³