Features 3″ High-temperature voice coil 145 oz. ceramic ferrite magnet High-grade Low Carbon steel on top and bottom plate Designed to optimize SPL performance High excursion spider designed 1.5″ high roll foam surround Large gauge push button speaker terminals Dual 4 ohm voice coils Specifications Structure 12.18” (309.5 mm) Max Power 1500 Watts Nominal Power 500 Watts Impedance 3" (76.2mm) Dual 4Ω Voice Coil PARAMETERS Resonant Frequency (fs) 26.951 Hz D.C. Voice Coil Resistance (Re) 6.57 Ω Me