Z-5300 Speaker Set Crackling Issue

I'd be more than grateful with whomever can help me out with this. The issue arose this morning when I turned on my Logitech Z-5300 speakers, I noticed that one of the two speaker (Currently only using 2.1) was all distorted and muffled - not what I was expecting to say the least! I decided to get straight in and try and fix the problem on my own.

Typically my speakers are connected to my laptop, so thinking logically I dashed into the other room with my Z-5300's under my arm (Okay, it took about 4 trips there and back), hooked up the speaker system to my PC's 5.1 sound card which used to run my Z-5300's. I heard a lot of crackling and popping out of only one speaker, the other speaker was playing the music perfectly.

By this time I was on a roll, thinking logically once again I switched the speakers over at the back of the sub-woofer. Now the left speaker was plugged into the right socket, and vice versa. I had the exact same issue, only now the problem has been inversed. I deduced from this that it was perhaps the actual sub-woofer connector. I continued to plug the speakers into different sockets and found that the front right and rear right channels were all copasetic. While the other 3 channels were producing undesired crackling, popping, and every other sound you'd rather not be hearing your speakers project!

I have been doing my own research on this matter and I've found some people saying that a can of compressed air into the volume control (More specifically the volume's pot - which I'm guessing is the component below the volume control if I am right in assuming pot is the short-hand adaptation of potentiometer). There have also been some advice given that has been more inclined towards people spraying contact spray onto the volume pot.

I do have a few questions, aside from why is this happening to me and how do I solve this - naturally, and these are as follows.

I know it's not the speakers but rather the channels on the sub-woofer. Front and rear right work brilliantly no matter which combination of the 5 speakers I plug into them, and the other 3 channels (Center, front and rear left) do not work. Could the volume control be responsible for such an unfortunate situation? To me it seems like this issue is far beyond the control (no pun intended) of the volume box and seems to be more down to the sub-woofer itself. I feel the volume control is my innocent scape-goat.

Would anyone have any cautionary objections to me applying contact cleaner into the volume control? Or spraying compressed air into both the volume control AND the sub-woofer? I know speakers have a tendency to behave badly when specific elements come into contact with pesky dust, but as aforementioned, could this explain my situation?

Just to reiterate that it's not the speakers but rather the channels themselves (3 bad, 2 good). Any help would be much appreciated!

Hmm, i'm thinking it's the sound card. If it's a creative one, then definetly the card, you need to upgrade the firmware but check it first

But would this explain why it doesn't work on both my laptop and PC? I somehow think it is the dust on my sub-woofer or volume potentiometer.

Hmm how hard is it to take apart your speakers?