This is in response the to the above post I left last week.
16 Macbook Pro USERS W/ AUDIO Issues Please READ: (esp ones with external/digital mixers that get their sample rate/word/Clock info from another device)
I purchased a 16 MB Pro fully loaded in March. Have been having sporadic issues since then, recently upgraded to Big Sur to see if the problems would go away. Problem still existed.
My issue was sporadic audio sounding garbled after 15-40 mins that would start out of the blue. Sessions would start fine, but after 20 minutes, sound would start to sound garbled and get worse after a few minutes. Based on other threads I read with users having similar issues, I was convinced it was a hardware/driver/thermal issue or Apple bug.
I spent many hrs comparing log files from when I was having the problem to see if I could find something in the logs that could be causing problem. As part of searching for other users having similar issues, I came across a few things that were related to digital audio sample rate/clock settings. If you have multiple pieces of equipment that are digitally connected, you need to make sure all the equipment is synchronized properly. If you're having audio issues that start out of the blue, for example after 20-40 minutes, that are resolved by changing buffer settings or restarting CoreAudio, but eventually come back, etc then check your clock source and make sure it's solid. Keep reading to see how I figured out what my problem was. Solution is to make main mixer the Clock source, and other devices slaves, and make sure your cable providing word/audio sync is good and not being subjected to static etc. My problem appears to be a bad cable from my main mixer that was getting audio sync/sample rate data from another mixer. It was hard to troubleshoot because the audio problem was not immediate. It was sporadic, usually after 20-40 mins. Likely some type of interference that caused the frame rate to be read incorrectly by the Macbook.
Heres some more detailed info in case you are experiencing a similar problem.
I have a complicated studio setup where I have multiple digital mixers connected to each other with a special cable. (AES50 - it's a sheilded Cat5 cable). The cable connects the devices, and allows for sharing of audio AND Clock/sample rate data.
I have confirmed that the audio problem I have been having, at least recently , appears to be the result of my Macbook Pro not getting proper Sample Rate/Clock information from my primary digital mixer. (The mixer was setup as a slave, and was receiving word/clock/sample rate data from another digital mixer via the Cat5/AES50 cable). I have determined the reason why I am getting audio problems after 20-30 minutes of use is because the mixer connected to my Macbook is dropping work clock data. I confirmed this by changing the primary mixer as the master clock source. Since doing this, I have had no problems with audio at all. I wanted to post this to correct my previous post where I said that after upgrading to Big Sur I was still having audio problems. That was true, but the reason for the issues was due to bad/incorrect word clock/sample rate data that my digital mixer was receiving from another device. This took me almost a month to figure out, so hopefully anyone else with this problem will see this and not assume it's a hardware issue with the Mac. Sample rate/clock issues with the hardware/mixer your Mac is plugged into need to be considered as well.