I have a 2.1 Logitech Z4 setup, and the sound is only coming out of the left speaker. I have checked the wires, they are fine, and both speakers do work - but it could be the socket that's the problem. It's plugged into the line-in socket, I have put the output in System Preferences to Headphones, and everything is inserted correctly. What do I do? Thanks EDIT: My sound system is plugged into the headphones jack. I have tried putting headphones into the headphone jack and the sound also only comes out of the left earbud.