M-Audio Revolution 7.1 Surround Sound PCI Card ( PC / Mac ) Output for up to 7 powered speakers plus powered subwoofer 7.1 places speakers both beside and behind the listener, for an incredible immersive sound experience Includes Dolby Digital EX DVD Player software for Windows Also supports 4.1, 5.1 & 6.1 formats Full support for Microsoft Windows Media Audio 9 Professional