JBL Stadium 122SSI Stadium Series 12" component subwoofer with switchable 2- or 4-ohm impedance at Crutchfield
Focal Sub 12 Dual 12" Subwoofer, Dual 4-ohm 300w Rms - 600 W Max : Target
Crossfire Audio C5-V3 12" inch DVC D4 Ohm (C5 Series) Car Subwoofer 600 Watts RMS
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TXX-BDC4-12 Subwoofer - Quad Stack | Audiopipe
Amazon.com: H YANKA 12 Inch Subwoofer - 12 Inch Paper Cone Subwoofer Car Audio, Black Steel Basket, Dual Voice Coil 4 Ohm Impedance 12 subwoofer, 1600W MAX Power 12 inch Competition Subwoofer : Electronics