if you have a dsdt patch using layout 3 the darkvoids files will not fit for you, because he use layout 1
anyway, don't waste your time trying, i did it already and the issue with microphone is still here.
would be interesting to know if any of the guys using the Dell laptop with alc668 suffer of the same issue with the internal mic as we are experiencing. the issue is even weird to explain, seem it record at a wrong sample rate so the audio is reproduced way slower than it is captured
i'm on el capitan now, but the issue is present with every patched kext released by mirone for yosemite also.
my setup use a dsdt patch+a clover patch for vanilla applehda and a dummy kext for the 668 as the darkvoid use on him.