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Amazon.com: Massive Audio SUMMOXL154-15 Inch Car Audio Subwoofer, High Performance Subwoofer for Cars, Trucks, Jeeps - 15" Subwoofer 1500 Watt RMS, 3000w MAX Dual 4 Ohm, 3 Inch Voice Coil. Sold Individually : Electronics
JBL Grand Touring Series GTO1204D 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Turbosound iQ18B 3000W 18 inch Powered Subwoofer with DSP | Sweetwater