I'm not sure which connectors you're referring to because I'm not at home to look at my sub but it sounds like perhaps only your front speakers are working. If that's the case then you should probably go into your settings for your soundcard and ensure that they are set to 4 speakers and not 2 speakers. That's about all I can tell you with the info you've given, if that doesn't work then give us some more specifics on it and I'm sure someone here will be able to help you out. Hope it helps.