My PC speakers are making weird noises...

[Clypher]

I have the Logitech Z-5500 set. I just put together a new PC for myself and was having no issues. Then the PC crashed, so I redid everything today.

Now my speakers make a barely audible "thud" every few seconds, and occasionally a series of them... sounds like a double kick on steroids.

What I've tried:
I have tried using both onboard sound and the sound card I have (Creative X-Fi), and have tried a different outlet, neither of which solve the problem.

More info:
-It will tick every 2 seconds, and then it really starts going when the computer does something, like loads a page, or copies a file.
-It only happens when they are connected to the computer. If I turn them on while disconnected they are silent.
-However, if the computer is turned on or off, it still makes the noise if the speakers are connected.
-It will happen EVERY time I switch the input mode on the Z-5500 control.
-It is not affected by the volume setting. Hitting mute on the Z-5500 control does not stop it, hitting mute in windows does not stop it.

It really seems like it's connected to the power. I can only guess something with the amplifier went bad when the computer crashed the first time.. how I don't know.

Can anyone help me?

 

[jonnythan]

edit: nevermind. That's what I get for not reading the whole post.

 

[Djizasse]

Disconnect your pc from the 5500. Then try them with a mp3 player or other source of audio.
Let's see if the PC is the culprit.

 

[Clypher]

I found the culprit. It's the powerline ethernet adapters i have. When that thing is plugged in it interferes. That's why when i loaded a page on the net it got worse.

i'm going to try a power cleaner sort of thing, see if that cleans up the signal for the speakers.

Well that didn't work. Still made the same damn noise. I don't know what to do, I need sound, and I need internet. Why can't the two live in harmony?

OK i confess, i was lazy the first time and didn't plug everything in right. Now it works.