Static Noise From Speakers

Ok, so I had a pair of cheap Logitech speakers ($15) that I used on my laptop, and often times a static, crackling sound came from them. I figured it was either the speakers, or the computer itself. Then, when I built my new computer, they still had the noise, so, I figured that I had isolated the problem. It was clearly the speakers. Two days ago, I got a pair of Creative speakers for about $45, and they look a lot nicer, and are overall much higher quality. For about 36 hours or so, they worked perfectly. Then, I heard the static again, and it continued. I use an HDMI cable, and I switched it out for another cable. Am I just extremely unlucky? Did I get multiple pairs of dud speakers? The last culprit that I can think of is the monitor. Is there anything else that anyone can think of? Thanks.