fletcher5555

OK guys now i really need help with this one. I have my Car PC hooked up under my passenger seat which is being powered offa 240 volt inverter. Now I bought a Amplified Graphic equaliser to help me power my front and rear speakers so I install it and have a buzzing noise coming through the speakers. I check all the wiring which is OK and so swap the input from my computer to my little mp3 player and the buzzing is gone.
What I do next is power my pc off the Mains from my house (thanks to an extension lead) and the buzzing again disapears so it seems like the noise is occuring somewhere between the inverter and the step down transformer that comes with the pc. Does anybody ahve any ideas what I can do to get rid of the buzzing? I have no idea how the equalizer is picking the buzzing noise up as the amps and subs work perfectly its just the amplified equalizer powering doorcard spekaers which is buzzing. Now im Very experienced in electronics and a friend of mine is a MASTER TECHNICIAN for ford and we still cant find a way around it other than trying a new inverter. Any hekp would be much appreiciated plus you would get the bonus of saying you know more than the Head mechanics at Ford motor company. Thanks in advance for your help!