SeaKing Stores › 12in shallow car subwoofer - 4ohm DVC - R2SD4-12 12in shallow car subwoofer - 4ohm DVC - R2SD4-12 £115.00 12in shallow car subwoofer - 4ohm DVC - R2SD4-12. 250W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated. Add To Cart Added! 12in shallow car subwoofer - 4ohm DVC - R2SD4-12. 250W RMS. Standalone driver, sold individually. Car-audio product; not marine-rated.