[popcornmix]

sorry for being such a noob, let me know if there is anything you want me to test/do

Using ssh, you can check the value of a config.txt setting:

Code:

vcgencmd get_config no_hdmi_resample

It should be 1 if not specified in config.txt.

Assuming it is currently 1, then just keep an eye out for crackling (ideally watch the video that gave you the problem again).
I imagine it only affects certain audo formats/samplerates.

If you hear it again, the add no_hdmi_resample=0 to config.txt, reboot, confirm it is present with the command above, and see if it's fixed.
To be sure you could remove it, reboot, confirm and test once more.

I'm quite interested in this, as I have heard the crackling in the past, but not for a long time, and would like to be sure if it's still present.