I need help solving the following issue...

I have the Creative GigaWorks T40 Series II speakers, and for the last 2 years I've had constant static/crackling sounds coming out of my left (secondary) speaker when powered on. This is regardless of whether or not I have anything plugged into these speakers, so it is definitely an issue with the speakers themselves. This started to occur when the power cable was accidently unplugged from the back of the right (primary) speaker when still powered on. I've noticed that the volume of the static/crackling will go up when I turn down the bass and treble knobs on my speakers, and it will become quieter when I turn them up. The volume knob on my speaker on the other hand does not affect the static/crackling noise whatsoever. I am also speculating that colder room temperatures are causing the static/crackling noise to become louder, as during the winter the static is really loud, and during the summer it is barely audible.
In case you are wondering, this is what I mean by static sound: youtube.com/watch?v=hSGNXY_CEbg

Does anyone here know what the issue could be, and if an audio noob like myself would be able to fix it?