Under Seat Ultra Thin Car Subwoofer Slim Active Amplifier Speaker 600W 10 Inch. The item “Under Seat Ultra Thin Car Subwoofer Slim Active Amplifier Speaker 600W 10 Inch” is in sale since Sunday, October 28, 2018. This item is in the category “Consumer Electronics\Vehicle Electronics & GPS\Car Audio\Car Subwoofers”. The seller is “uniqueitemsshop” and is located in Hong Kong. This item can be shipped worldwide.