Description. The redesigned M-Series All-in-One 2.1 Home Theater Sound Bar from VIZIO, America’s #1 Sound Bar Company, combines supreme convenience with powerful performance. Thrilling sound is achieved with separate tweeters and woofers, plus built-in dual 3” subwoofers, all in a striking angular shape with a dark charcoal finish.. Model: M21d-H8 VIZIO 2.1 Channel Sound Bar with Dual Integrated Subwoofers Please read this guide before using the product. U SER . MANUAL. Please read this guide before using the product. w. USER MANUAL. Model: M21d-H8 . V .1 Channel ound ar with ual ntegrated ubwoofers. Please read this guide before using the product. VIZIO M21D-H8 M-Series All-in-One Sound Bar. The redesigned M-Series All-in-One 2.1 Home Theater Sound Bar from VIZIO, America's #1 Sound Bar Company, combines supreme convenience with powerful performance. Thrilling sound is achieved with separate tweeters and woofers, plus built-in dual 3" subwoofers, all in a striking angular shape with. "/>Vizio 21 m-series m21d-h8 review