Summary: Type: subwoofer; The number of bands: 1; Power: 850 watts (maximum); Housing: no; Additional information: Recommended amplifier power: 50-850 W. Nominal impedance: 2 and 4 Ohm. Resonance frequency: 33 and 34 Hz. Diameter mounting hole: 234 M. Massive double design of the magnet. Massive copolymer cones. Balanced suspensions.; ...