Spend your money on a DSPeaker product and use affordably priced low level RCA or balanced interconnects to have unrestricted room placement of the subwoofer and direct amplifier to speaker connectivity. Or better yet put your money towards a REal direct radiating JL Audio E sub.
http://www.dspeaker.com/en/products.shtml
Most all other powered subwoofers offer high level connectivity as a secondary connection option to be used with single output pre amplification.
http://www.dspeaker.com/en/products.shtml
Most all other powered subwoofers offer high level connectivity as a secondary connection option to be used with single output pre amplification.