Ok, so my computer speakers are hooked up to my computer?s sound card. They are 5.1 Logitech speakers, hooked up to the soundcard by 3 mini stereo plugs.

The speakers along with all my other computer stuff are plugged into a UPS, and the UPS is plugged into the wall socket of my bedroom.

So here?s the problem: I set up a christmas tree in my living room with blinking Christmas lights. Every time the lights blink on, my speakers makes a brief crackle.

Any idea why this would happen?