SeaKing Stores › 15in car subwoofer - 4ohm DVC - T1D4-15 15in car subwoofer - 4ohm DVC - T1D4-15 £590.00 15in car subwoofer - 4ohm DVC - T1D4-15. 1000W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated. Add To Cart Added! 15in car subwoofer - 4ohm DVC - T1D4-15. 1000W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated.