VIZIO SB4021E-B0 40-Inch 2.1 Home Theater Sound Bar with Wireless Subwoofer (Black) 101dB of room rocking, crystal clear sound with less than 1% total harmonic distortion* Stylish and slim - perfect complement for 42" and larger TVs Wireless subwoofer adds rich, powerful bass from up to 60 feet away Exceptional audio performance with SRS TruSurround HD and SRS TruVolume technology Sound Pressure Level measured using pink noise at 1 meter, C-weighted. Total harmonic distortion calculated as electrical measurement of amplifier distortion.