Network time synchronization causes audio overloads

Number:rdar://46918065 Date Originated:
Status:Duplicate of 45462730 Resolved:
Product:Audio Product Version:
Classification: Reproducible:Always
I've been having random audio overloads on my new 2018 MacBook Air. After browsing several logs, I noticed that IOAudioEngine::pauseAudioEngine() was called immediately after the 'timed' process attempted to synchronize the local time to a network time server.

This issue is 100% reproducible and persists across reboots. While audio was playing, I opened up Date & Time preferences and repeatably toggled the "Set date and time automatically" check box. Each time I turned this setting on, I saw a log entry for IOAudioEngine::pauseAudioEngine(). These pauses are often long enough to cause an audio overload.

Steps to Reproduce:
1) Have a MacBook Air 2018 and an audio device whose "Clock Source" isn't "Default". I used both an Apogee Groove and a Focusrite iTrack Solo.
2) Turn on "Set date and time automatically"

Expected Results:
No audio overloads, glitchless playback

Actual Results:
Whenever "Set date and time automatically" is first turned on, or once per hour when 'timed' runs, audio glitches due to something calling IOAudioEngine::pauseAudioEngine() at the kernel layer.

10.14.2 (18C54)

2018 MacBook Air + Apogee Groove 

Test matrix:
2015 MacBook Pro + Built-in Output = ok
2015 MacBook Pro + Audioengine D3  = ok
2015 MacBook Pro + Groove          = ok
2015 MacBook Pro + iTrack Solo     = ok

2017 iMac Pro + Built-in Output = ok
2017 iMac Pro + Audioengine D3  = ok
2017 iMac Pro + Groove          = ok
2017 iMac Pro + iTrack Solo     = ok

2018 MacBook Air + Built-in Output = ok
2018 MacBook Air + Audioengine D3  = ok
2018 MacBook Air + Groove          = FAILED
2018 MacBook Air + iTrack Solo     = FAILED


Output from console:

By ricciadams at Dec. 22, 2018, 10:44 a.m. (reply...)

Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!