If running Yosemite 10.10.2 with Clover(...)
The issue is the developer has not posted his solution on this forum nor replied to posts in months. No user clicking on your Post #1 link can assume support from any forum other than from the linked thread.Many of us have used and appreciate your HDMI solution, but, unless I'm mistaken, this forum is not dedicated to it. Andre's solution works well, and if it can help someone enable HDMI audio on their Hackintosh it shouldn't be censored.
^ Here it go: http://patrovic.com/HDMIAudio-1.1.dmg
But it didn't work with my GTX 970 GV-N970IXOC-4GD and Asus Gryphon z97 MATX
Worked for me, i have a GTX970 Armour, although the Hdmi audio goes into my monitor speaker just fine i can't change the volume using the apple volume slider / keyboard keys ... =S