Electric "buzzing" from speakers

[Gazi]

I have an issue with my old creative speakers. When i have them turn on and hold front pannel cabble in my hands its starts buzzing in speakers, but when i touch my case(lancool k58) with it it makes ieven lauder buzzing(even if my pc is disconnected from power). In my all system i even heard big, shurt "buzz" during boot up for years, new rig doesnt have that but still.

Is it safe for my pc? Is there something wrong with speakers or something(those are subwoofer and pilot speakers)?

 

[photonboy]

It sounds like a grounding issue.

1) Disconnect the PC wire and try a different input device (like iPod, laptop etc). So speakers are NOT connected to the PC.

If that works the issue is the input coming from the PC.

2) Do you have the front panel audio connected to the case?

If so, try removing the front audio (at the motherboard). If that doesn't work remove the front USB connector as well since apparently touching that caused problems.

 

[Gazi]

but is it dangerous for the pc?