VIZIO SB4020M-B0 40-Inch 2.0 Home Theater Sound Bar 95dB of crystal clear sound with less than 1% total harmonic distortion The perfect home theater solution for 42" HDTVs and larger Powerful audio performance with Dolby Digital, SRS TruSurround HD and SRS TruVolume technology Connect to your TV with an easy, one-cable setup Sound Pressure Level measured using pink noise at 1-Meter, C-weighted. Total harmonic distortion calculated as electrical measurement of amplifier distortion.