Posted 04 December 2010 - 03:56 PM
Test to see if it's hardware related.
Get an audio (not video) file and put it on your desktop.
Play the file from your desktop, and ascertain that there's no crackling.
Burn the audio file to a CD, put it in your cdrom, and play the file from your cdrom.
If there is crackling, then you may have faulty audio components in the cdrom itself (less likely, but possible, is a faulty audio cable from the cdrom to your motherboard).
Try a different cdrom in your system if possible.
If the sound is clear, then the first cdrom is the problem. If there's crackling, then the "cdrom in" circuitry (where you plug in the cable from your cdrom to the motherboard) on your motherboard may be at fault.