ga-k8nf-9 and front audio connectors

I want to wire up the front audio connectors so that when I plug a front
audio output and microphone cable, it cuts out the rear connectors.

I also have a ga-k8nf-9-ultra with the same front audio connector. i'm using
it an Acousticase C6607 system case which comes supplied with a header
cable, and works a treat.

I'd like to do the same using the k8nf-9 in a basic system case, but one
where i've installed an Akasa front audio panel. I've got 3 pins as output
from each of the two cables (speaker and microphone) but I'm not sure how to
connect them to the front audio header. I've tried various combinations. I
couldn't get the microphone to work at all, and the sound was very quiet.
When the speaker out cable was removed it wouldn't revert to the rear audio
out, which does happen on the ultra.

Any ideas?

Mike