Alright. I think that I've finally found at least one set of conditions that leads to this issue and a couple fixes (one that sucks and one that a lot sucks less). So I've been closely monitoring CPU / memory usage and the states of things when there are no pops and when the pops start showing up.
Essentially, what I'm seeing is that when there is memory pressure that goes into the "yellow" in your Activity Monitor, which for me happens during usage and pretty much only when memory usages hits the ~14GB of usage mark (on a 10-core, 16GB build). CPU usage doesn't seem to always have a direct impact, but I have seen that when I trigger something heavy on the CPU and stop it, that can trigger a pop sometimes (inconsistent). It seems like some CPU usage / swapping / etc. is at the least correlated with this issue. This tracks with what @virgil237 said above re: his memory usage being at 14GB.
Would love to hear if anyone using a larger build (32GB) or if you have a friend with one has the same issue when hitting the yellow, but not before. At least that would give us something material to run up the flagpole and get an Apple dev to look into. Also, considering whether to return this 16GB build and just go with an M1 max 64GB build and skirt the issue altogether as I'm guessing a fix won't be forthcoming very soon in any case.
The first fix, as you would imagine is...close things until you get under the 14GB mark and in the "green" and it seems that the issue is at least MUCH rarer, going from every minute or few to once in awhile. Not sure if this will be a software fix or a firmware fix. What is still interesting is how this still does not happen via Bluetooth at all. So, there's something there that further narrows down the possibilities for a sound system Apple dev out there. Core audio daemon routing specifically to the internal speakers?
That got me thinking about audio routing, so I went to get SoundFlower to play with some audio routing to see if I could route through SoundFlower and then to the Speakers with any improvements. SoundFlower not supported on M1 macs yet, which led me to the BlackHole 2ch audio router (existential.audio). So in the Midi Device setup you can add a Multi-Output device and make BlackHole 2ch the primary and set the speakers as the other device. Then set your main output device to the Multi-Output device. So far, popping is either gone or at least a lot rarer. Note that I'm still running heavily into the yellow in memory pressure with no popping. The one caveat is that you have to change volume in the Midi Setup due to the way the devices work...that may be easy to find a control for given all the good DAW software / routers out there. Seems like this should help a dev narrow things down even more. @Apple please look into this.
Hope this helps someone not go crazy. Let us all know your mileage with the proposed fixes and / or other solutions you find! I'll report back on whether this second fix seems to hold or not.
