Mac Book 2018 USB-C Audio Issues


I was working on the issue that the RME UFX II was producing audio glitches with my new Mac Book Pro and High Sierra.

I had to do the following:
Boot with Command-R
Open Terminal
csrutil disable
Move this file to somewhere: system/Library/Extensions/AppleSmarBatteryManager.kext
kextcache -system-caches

Startup Security Utility => Security Boot => No Security

When you do not change this, the AppleSmartBatteryManager extension is loaded always!


Open Terminal
csrutil enable

I also disabled the location services

Yesterday in a rehearsal I did not notice any Audio glitch.
I had a TelKo with Apple Support and they confirmed issues with usb-c Audio and High Sierra.

Now I will check Mojave when it comes out and will see if the hack described above is still

Did anybody the same trick?
What are your experiences?
Anybody used Mojave Beta?


I have audio glitches with my MacBook 2018 and MOTU 828es. I will try your trick when I get the chance in a few days.

Please let us know how Mojave works for you!


Sure, will do that


I’m staying on 10.12. Much as I love been an early adopter, these upgrades don’t seem to add that much that’s relevant and generally they’re a headache. I still remember when 10.9 completely broke aggregate audio devices.


Yesterday I upgraded to Mojave and in a 1st test everything is working.
Plugins in GigPerformer and RME UFX II is working, but until now I am using the battery hack.
Will get rid of it and see if something has been improved in Mojave.

Over the weekend will stress test and come back with results.


Next result: Audio Issues are not worse in Mojave than in High Sierra :wink:

Today I have a call with Apple, will come back with results.


Had a call with Apple…
Now I should reset NVRAM and SMC.
Will come back with results.


That sounds like a typical first level “reading from a script” response.


Yes but now it has been escalated and the engineers are informed…


Now it is an official bug and Apple seems to work on that.

Here you can download the latest driver from RME:


After months of investigating with Apple Support I will bring the Mac Book Pro 2018 to my local dealer.
Hope they find the root cause.

I did a fresh install of mojave and Gig Performer, loaded some plugins just to stress the cpu and with audioplayer and some tracks audio glitches occured.

Apple support told me to check the hardware by the local dealer.

Seems that only the 15“ Model of the new Mac Books Pro face the issue with audio.


Oh that’s a bummer… let’s hope for the best :wink:

Do you have that “stress-gig” file or a hint how to really stress a MBP ?



Just use psp lotary 2 many times in a gig and you can stress


Now there is a new driver from RME for Mac:

You can download it here:
Driver 3.14 Mac


This diver is working fine - until it fails…
The next step was to test the latest Beta Mojave 10.14.3
For about 30 Minutes no single glitch occured, then suddenly a total crash of the mac book pro.
I reported that to Apple.

Then I found a forum entry which said that using a Thunderbolt to USB hub is the solution.
I asked RME and they said, that is true.
I ordered such a hub today, will come back with results.


I wrote an E-Mail to Tim Cook and was contacted by Support - again.
But now the Engineers take care of that issue with USB-C and Mojave on Mac Book Pro 2018 with the new T2-Chip - at least they said…
I tested with the latest Beta 10.14.4 Beta 2 and the issues still exists but at very low frequency.

I also used a Thunderbolt to USB Interface from Caldit and the massive audio issues do not exist anymore.

So there is light at the end of the tunnel (hope it is not a train …)


Getting serious…


Purchased a Thunderbolt 3 dock. This fixes any of the current drop out issues until Apple fixes it.
Caldigit Mini Dock


I am using the same and in rare cases I get a very short glitch.


Thanks for responding…
That’s odd, because from what I’ve read, the dropout issue is only present when plugging a USB2 device directly into one of the thunderbolt 3 ports with an adapter. If you use a true thunderbolt 3 dock, and plug your USB2 audio interface into it, then you’re using the USB2 bus in the dock, not inside the Mac. I’m surprised you still experience glitches. Mine arrives tomorrow and I’ll start testing.