This is a 2.1 system based on the top of the line Z-680. Take Logitech's award winning top of the line Z-680 5.1 speakers, remove the center speaker, rears speakers, surround sound break-out box and you will have the Logitech Z-2200. Logitech markets the Z-2200 as a THX certified speaker system which sounds great for people who doesn't understand what THX is all about. Those who do know what THX is about will know that having a THX stamp doesn't mean much anymore. This doesn't mean the Z-2200 sound bad or don't perform well. On the contrary, these are among the best multi-media speakers I have ever had the pleasure of listening to.