The JBL Duet multimedia speaker system provides smooth and accurate sound for any portable music player or computer. With its incredibly easy setup and use, Duet is a sophisticated approach to achieving great two-channel sound. Duet uses patent-pending Tangential Strain Relief (TSR ) technology that was designed specifically to deliver extra bass and lower distortion in small enclosures as a result of controlled linear excursion of the speaker. It also provides superior midrange- and high-frequency reproduction. The neodymium magnet creates more power and sensitivity. Duet also uses a proprietary Adverse Pressure Gradient (APG ) port design, which greatly enhances the bass performance. Self-powered satellite speakers Volume controls on satellites