Ground Zero Hydrogen GZHW 20-D1

Model High-Performance Subwoofer Diameter 20 cm / 8″ Power handling (RMS/SPL) 700 / 1500 Watts Impedance 2x 1 Ohms Efficiency 80 dB Power recommendation 50 – 1500 Watts Voice coil 63 mm / 2.5″ Copper Cone Reinforced paper Max. Excursion (Xmax) 40 mm / 1.57″ Mounting Ø 187 mm / 7.36″ Mounting depth 145 mm / 5.71″ Resonance frequency (Fs) 38.3 Hz Overall quality (Qts) 0.381 Equiv. air volume (Vas) 4.77 L / 0.17 cu.ft.