Computer question - "Static" on audio output

Factual Questions
1

Hey guys!

I recently moved from one room to another in the same house, and when I plugged everything in, I noticed that the speakers started making a static sound on certain frequencies! (For example, one notable example was the lacrosse scene in American Pie, where the coach’s voice, and only the coach’s voice, would be accompanied by some static). In most cases, whenever something loud is played, the static becomes louder.

So, my gut reaction was that somehow the speakers were damaged in the move, but today, I swapped out the 2.1 speaker set for a 2.0 home theatre set (from 1987!), and I just noticed that the same static occurs.

It seems like the problem isn’t the speaker set… to make sure I plugged it into my laptop, and noted that the static problem disappeared.

So, what could it be? The only variable is the computer itself, and I’ve tried both sound ports (back and front), to no avail. The best solution seems to be to purchase a new sound card, but this would only solve the problem if the problem actually lay with the motherboard. If that were the case, then there’s no guarantee that a new sound card would be static free, since it would still have to interface with the mobo.

Any ideas on what the problem actually is, or how I can mitigate it?

2

I’d have two instincts on this.

  1. It’s the sound card/sound processor that’s on the fritz. Sometimes they wear out and get wonky. On my old homebuild something similar happened to the on board sound and I just installed a $10 PCI sound card and everything was fine.

  2. There’s some interference with the sound wire or speakers in the new configuration. Sometimes speakers and other components can get screwed up by being positioned or run too close to the monitor, PSU or other high-power component. Even a lamp or power cord from something on the desk or plugged into the same outlet.

If it’s problem #1, the solution is pretty easy. Buy a cheap card and see if that fixes it. They are simple to install and you can return it if the problem is persistent.

If it’s #2 it’ll take a little sleuthing. I suggest removing everything non-essential from the back of the computer and removing any electric wires. Make sure the speaker wire is well isolated and away from everything. Test it out with both sets of speakers.

If you’re still stumped you might want to open up the case of the PC and see if any of the wires in there shifted. Perhaps a power cable or other internal cabling got jarred so that its resting against the mobo in a weird way that interferes with the sound. Make sure any loose cabling is bound and attached to the case and routed away from the mobo and all components.