Crackling speakers?

I just got my Dell Inspiron 7352 less than a month ago, and I use it pretty vigorously. I listen to music occasionally, but lately I've been noticing a crackling sound over the music. Sometimes if I restart the computer completely, it stops, but not every time.

I ran product support & diagnostics and everything passed, but I also updated the drivers "7352_Chipset_Driver_H3X46_WN32_10.0.30.1072_A01.EXE" and "7348_7352_7558_A07.exe" because dell system detect under Drivers & Downloads said I needed them. However, the crackling is still going on.

Also, if it's important to know, I've been getting an error message saying that my "AC power adapter type cannot be determined" and I need to "connect a dell 45w AC adapter or higher". The AC adapter I am using is a 45w, the one that came with the computer. I assume that I am getting the error message because the AC adapter was extremely hot several times, almost too hot to touch, and It must have been damaged from the heat. So I plan to get it replaced, but do you think that that would be causing the crackling from the speakers? The error message said the system will operate slower, which I have noticed, but I'm wondering if that's connected to the crackling coming from the speakers. If not, then oh well, I just don't want to be missing any possibly important information. 

The computer itself has also heated up a bit before I got the chance to get a chill pad to keep it cool. Maybe the heat damaged the speakers? I use this computer alot, so it's possible it's just wear and tear from use. I just feel like it's a bit new to be showing problems.

thanks for any help you may offer!