No surprise, there are no BR3A ssdts in the Post #1 repos. Attach an IOReg.I tried the X99 BR3A SSDT and it didn't work for me.
S/L/E/HDAEnabler1.kext interferes with HDMI audio, remove.Here is my IOReg.
S/L/E/HDAEnabler1.kext interferes with HDMI audio, remove.
1. Onboard audio, install ssdt_hdef-1-x99_alza.zip, confirm 1150 audio working.
2. Nvidia HDMI audio, install the BR3A ssdt from Post #7.
Try attached.HDMI but wasn't under output devices