Enabling HDMI Audio

Enabling HDMI Audio

While video will work off the bat, HDMI audio, generally will not. This is where you need help. Thankfully Mac Pro users can learn something from the Hackintosh community, a group that enjoys getting OS X or macOS to run on their commodity PC hardware.

For more information on how to build a hackintosh visit https://hackintosh.com/ or follow The Always Up-to-Date Guide to Building a Hackintosh at LifeHacker.com

While the subject of building a ground-up hackintosh is a lengthy subject best left to the experts, the issue of upgrading Mac Pro Video cards to something from this decade is something more manageable and the subject of this article.

Once you have your 2019 video card up and running, it’s time to start work on HDMI Audio. To do this we need to install a few kexts (drivers) and to do that you need to temporarily disable some of the new security features introduced with Sierra like GateKeeper and System Integrity Protection. To accomplish this we need to fully Power Off the system and boot into recovery mode. Power on the system and hold down CTL + R as soon as the system begins to start up and continue to hold down till the Apple icon starts to show. From the Utilities menu open a Terminal window and enter 'csrutil disable' then shutdown or reboot.

Next lets disable Gatekeeper which prevents signed Apple applications from running. To do this open Terminal and enter ‘sudo spctl --master-disable’

Now we can install the 2 kexts needed to enable HDMI Audio. These will be installed and registered in the /system/library/extensions folder. Google for the latest files on GitHub or use these which work on MacOS 10.12 to 10.14.

Unzip each of the files and place the KextUtility application and both kext files on the desktop, then open KextUtility and enter your admin password. It will take a few minutes to load up and perform some maintenance tasks so let it finish. Then in drag Lilu.kext onto the Kext Utility window and let the KextUtility install it. When it has finished do the same with AppleALC.kext. You will need to re-authenticate for each of the installs. Once the process has finished, close any open applications and reboot. To see an HDMI Audio output device you will need to connect your HDMI cable to a device with speakers.

To see whether the driver has loaded open System Report and go to PCI.

Then go to System Preferences / Sound and check Outputs. You should see whatever you have connected to the HDMI port – this will usually be the name of your monitor. Set it as the default output. You can edit this if you like using the WhateverName.app from its automatic state to something hard coded like HDMI.

Finally, go to your favorite music or video app, and check it out. If you don’t get sound change the Audio output device to either System Sound Defaults or to HDMI and enjoy HDMI sound.

I was able to get 4 upgraded 2009 Mac Pro systems (to 5,1) working with HDMI Audio fairly easily all running High Sierra – two with nVidia 7970 cards, one with a Radeon RX560 and the other with a Radeon RX 570. Upgrading to 10.13.6 however broke HDMI audio on my systems and I had to uninstall and reinstall with newer kexts.

I was also able to get a 5th Mac Pro with an RX 580 working with Mojave using the correct Kext versions. When I upgraded the other 4 Mac Pros to 10.14 Mojave, I had to remove the old kexts and install new ones.

My attempts to mirror the process on my upgraded 2006 Mac Pro 2,1 were less successful but it runs headless 99% of the time so I haven’t bothered to mess with it. It does appear to be possible however according to the forums.

Mac Pro towers also come built with a digital audio optical output port for a Toslink cable. So if you are unable to get HDMI Audio to work with your setup then simply revert to the optical option and use two cables rather than one - one for video the other for audio.

Please beware that OS updates may break this so be prepared to uninstall / reinstall with newer versions.

End of Story