VIZIO SB4531-D5 Smartcast 45&rdquo; 3.1 Slim Sound Bar System Three channel sound bar and included wireless subwoofer deliver incredible audio performance: 104 dB of room filling, crystal clear sound with less than 1% total harmonic distortion Download the VIZIO Smart Cast app2 to turn your smartphone or tablet into a powerful touchscreen remote Simply tap the Cast button from 100+ audio apps you already know and love to start playing on your sound bar.