Use:

$ pactl list | less -S

to check Your configuration.

Especially, the profiles at bottom of list.
1) Input Source: Microphone
2) Output Sink: Speakers

Not sure if it is too late, but I have Neon running on a Mac Book Pro 2015. I had audio issues as well (silent films on Netflix). I fixed it by making sure that kmix was installed as it is not installed by default. I don't know the technical parts but somewhere in the dependencies was the cure. Audio works perfect now.

hmm hope you don't mind a second pair of eyes?

Code: Select all

options snd-hda-intel model=imac27

I would change that to

Code: Select all

options snd_hda_intel enable=1,0
options snd_hda_intel model=imac27

reboot and see if sound becomes stable