I have a Creative Fatality1 Gaming headset and the mic doesn't work in this 3.5 port. It works fine on my work PC, so I know it's not the headset. The tech specs say the ports accepts digital or analog.
I have changes the input under system preferences to "system input"
As well as in the applications I use the mic
And in the midi-setup app in utilities folder.
Any help would be appreciated before I chuck a perfectly good set of headphones.