The Z906 Surround Sound THX-Certified 5.1 Speaker System from Logitech is designed to deliver theater-quality surround sound for your movies, games, and music. It features one subwoofer, four satellites, and one center speaker. In total, the system pushes 500W of power, with 165W being delivered through the bass-pumping subwoofer and 67W through each of the other speakers. This system is THX-certified and can decode both Dolby Digital 5.1 and DTS encoded soundtracks when you're using the speaker system to play DVDs.