SA-15 D4 - Sundown Audio 15" 600W Dual 4-Ohm SA Series Subwoofer
RE (ohms): 7.75    FS (Hz): 36.95    Vas (L): 52.35    Qes: 0.85    Qms: 6.63    Qts: 0.75    Le (mH): 4.98    BL (NA): 25.87    Mms (Grams): 315    Cms (uM/N): 58.8    Sens (1w/1m): 86.68    Cutout Diameter: 14 1/8"    Mounting Depth: 7 1/2"    Overall Diameter w/ Gasket: 15 5/8"    Displacement: 0.17ft^3    RMS: 600W    Recommended Box Specs (Sealed): 2.5ft^3 (Yields F3 of 41Hz)    Recommended Box Specs (Ported): 3.5ft^3 (Tune to 35Hz, Yields F3 of 28Hz)    19.0mm X-Max by 70% BL method one-way (38.0mm peak to peak)    Thick black anodized aluminum voice coil formers for maximum strength and heat dissipation    4-layer copper high temperature voice coil windings with 45mm winding length    Double layer permanently bonded high strength Nomex spider pack for maximum longevity and durability    Thick flat tinsel lead wires tied down to the spider to prevent lead noise and breakage    Custom tooled triple joint support ring    Custom tooled frame spacer / ventilation ring    High efficiency air-flow management integrated into the motor for maximum voice coil cooling    Dual Aluminum Faraday rings for reduced inductance and inductive distortion (pole cap and magnet ID)    Two-Year Warranty against defects in materials and workmanship