I am not 100% sure, but from memory the firmware basically do 4 things.
1) allow to use the newer CPU
2) allow the RAM run at 1333MHz (if CPU avail)
3) allow audio via HDMI (with 3rd party driver)
4) allow install OSX 10.12 natively
Anyway, the 1st thing I will check is system info -> PCIe section. If there is a device occupying the same slot as your video card, but no driver installed, than most likely that's the audio part.
Great I will check that when I get home. Thanks a lot for getting back to me so quickly. If that ends up not working, do you know where I can download the 2010 5,1 firmware?