I have a MacMini 2018, and am running 10.14.6. I encountered the crackling problem. you can tell it is a firmware problem in the Apple audio unit, because if you play music very softly you will hear the crackles. the crackles are fixed in volume and don't go up as you increase the volume. So this means that the noise is after the audio amplifier in the chain. The crackling stops when the audio stream stops, after a few second delay, when the audio unit goes to sleep (to save power). Killing the coreaudio process, which auto respawns almost immediately clears the problem. So it is a bug in the firmware for the custom apple audio chip which is in every MacMini and Laptop (they use the same custom Apple chips). It staggers my mind that Apple has had this bug since 2018 probably, and they just don't care enough to fix it. So obnoxious of an error for those of us who can still hear. Noise hurts your ear, and i didn't buy fancy Gelelec Studio Monitors to hear crackling! All the superstition about setting the time automatically doesn't sound plausible to me. It's a software error in the code that runs the low level chip. The engineer who worked on the chip is probably gone by now, and Apple doesn't fix problems unless thousands make a stink. Then they get off their ***** and fix things, because one thing apple cannot stand is public humiliation. — magicmouse less than a minute ago