I have recently just bought a Dell Inspiron 15 7559. Right out of the box, the audio seems to be quite odd with crackling sound every time a sound plays. I have a temporary solution which seems to work which is plugging in the headphones and removing them which allows the speaker to be fine. However, once I restart or shutdown the laptop, the problem exists once again. I have already updated my realtek hd audio drivers as well as a bios update. I don't think it is a hardware problem since the speaker can work without issue.