Audio cracks with Intel HD (and reflecting with some USB devices).
I had this problem with two different Intel HDs (also this problem reflects into my M-Audio USB). I'll let this registered here.
This solution is in case you have crackling sounds (something like a jitter from time to time) and an error in dmesg similar to IRQ timing workaround is activated for card #1. Suggest a bigger bdl_pos_adj.
In my case, disabling the onboard Intel HD in bios doesn't work and the jitter still occurs
options snd-hda-intel bdl_pos_adj=2,2
Your mileage may vary, so mess around with this number until it fixes for you, always using the power of 2.