Seems like adjusting the timing, even by one frame eliminates all instances of sound crackling and popping. I thought I didn't have this particular issue before until I've noticed it today (doesn't happen terribly often on my end). Whether or not this fixes the sound occasional sound lagging isn't known, but I'll do more testing and see how it goes.
For now, forcing the speed to 61 instead of 60 seems to work wonders so far.