I have had the Z906 5.1 series speakers for approximately eight years. It is understandable that after a while speakers will fail. I cannot understand why you cannot purchase replacement speakers separately or in pairs. I cannot even find the speakers to place inside their plastic covers. Now I have a faulty center and three satellite speakers that I have to get rid of. User's recommendation: Folks, do research before purchasing computer surround sound speakers and see if replacement parts are available.