SeaKing Stores › 12in car subwoofer - 4ohm DVC - T1D4-12 12in car subwoofer - 4ohm DVC - T1D4-12 £460.00 12in car subwoofer - 4ohm DVC - T1D4-12. 800W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated. Add To Cart Added! 12in car subwoofer - 4ohm DVC - T1D4-12. 800W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated.