A sound system that wants great power efficiency will definitely require you to use a subwoofer. Subwoofer has many good types, such as: JBL 728S, Martin S218, EKX118, BMB, Bose ....
Refer to the subwoofer product at http://bit.ly/2SjOdMZ
Refer to the subwoofer product at http://bit.ly/2SjOdMZ