macOS 10.14.4 Mojave seems to have not completely solved the audio problem on Mac with Apple T2 chip. Details are as below.
Apple released ” macOS 10.14.4 Build 18E226 “ and Apple’s OS “BridgeOS 16.16.4507.0” update on March 25, 2019 local time , this update supports AirPods (2nd generation) and In addition to security fixes, 2018 MacBook Air, MacBook Pro, and Mac mini USB audio as a fix to a problem that has occurred between the Mac and an audio device equipped with Apple’s second-generation Mac SoC “Apple T2” There is a statement that the reliability with the device is improved, but
It hasn't been spoken of much, but this T2 chip-related USB audio hiccup in the iMac Pro is every bit as bad as the butterfly keyboard problems. https://t.co/cfQWqEquNO
— Josh Centers (@jcenters) April 9, 2019
Improved reliability when using USB audio devices with MacBook Air, MacBook Pro, and Mac mini introduced in 2018
From macOS 10.14.4 Mojave Release Notes
According to Geoff Duncan, a Mac audio equipment and software consultant in Seattle, and the support form of each audio equipment maker, the problem with Apple T2 and USB audio devices has been improved with macOS 10.14.4. It does not seem to be completely corrected.
Report on macOS 10.14.4
Geoff Duncan has been experimenting with 42 tests using Pro Tools, Logic, GarageBand and other applications for 15 months on the Mac with client recording studios and the Apple T2 amateur musician. As it turned out , connecting certain USB / Thunderbolt devices seems to have caused glitches,
Although this problem is temporarily improved by forcibly killing the macOS time daemon (timed and located), it has not yet been solved fundamentally and the RME has been released last month even with macOS 10.14.4. Although some audio device manufacturers have reported that the problem has been improved, etc., users of T2 based MacBook Pro, CDM and RME Forum confirmed by Geoff have problems with macOS 10.14.4. It is reported that
Some audio developers (like Germany’s RME) have reported improvements with USB audio, but my limited testing with a T2-equipped MacBook Pro found no discernible improvement using 10.14.4 with USB or Thunderbolt audio devices.
What Does the T2 Chip Mean for Mac Usage? – TidBITS
Symptoms are reduced but dependent on hardware, possibly not entirely fixed. For now, the only sure solution is to use a Thunderbolt interface or Thunderbolt adapter. Sure enough, reader reports suggest this is a partial fix only.
Apple ships update it says addresses USB audio issues on recent Macs – CDM
It seems that CDM and Geoff expect compatibility problems between previously reported macOS Mojave and USB 2.0 audio devices / hubs to be the root of this problem, but USB 2.0 compatible for audio devices Geoff recommends that you consider an Apple T2 non-maintained Mac, as there are a lot of things, and Apple does not release information.
Just explained to another client that, yes, lots of USB hubs are broken under Mojave, yes, there aren’t enough USB ports for all your stuff, no, I have no idea if it will ever be fixed, yes, I told you months ago. #thanksapple
— Geoff Duncan (@geoffduncan) March 28, 2019