HDMI Audio + Video can be enabled on Mac OS X Lion for most graphics card and motherboard configurations without much hassle using the replacement audio driver VoodooHDA. Using the supplied AppleHDA.kext for HDMI audio is something of a challenge, but provides numerous benefits including native Mac OS X support, high quality digital surround audio and overall system integration.
Since Lion's launch, tonymacx86.com mod toleda has been exploring and experimenting using different methods, and has come up with what we think is a pretty definitive series of guides on the subject. Please note that this is an advanced process and is highly dependent on your exact hardware configuration.
Enabling HDMI audio in Mac OS X 10.7.x is comprised of three parts and six guides:
Part 1: HDMI Audio Requirements
Determines if your system is capable of HDMI audio.
Part 2: HDMI Audio DSDT Edits
Configures your motherboard for HDMI audio.
2a. Discrete Graphics - AMD/Nvidia
2b. Integrated Graphics - Intel HD 3000
Part 3: HDMI Audio Kext Edits
Customizes Mac OS X for your graphics card.
3a. AMD HD 5xxx and HD 6xxx
3b. Nvidia GT/S/X 4xx and GT/S/X 5xx
3c. Intel HD3000 Integrated Graphics
Check out the HDMI Audio subforum set up to host toleda's guides and general troubleshooting topics. Good luck, and let us know how it works for you!
by tonymacx86, toleda & MacMan