[ubuntu] 2015 Macbook (Macbook 8,1) No sound out of speakers, but sound out of headphones

This issue has been a bit confusing, and no matter what tricks i try, audio does not come out of speakers, but headphones only.

Any ideas on how to get this working? I'm running the latest ubuntu LTS.

Here's a basic lspci, if that helps:
Attachment 288659