Hi all! Just a quickie! I'm still using this Asus N550 notebook, mainly for KDE Neon (awesome Ubuntu-based distro). I had some issues with headphone jack socket so this is just information for googlers. In case you have issues like this just put following line into your /etc/modprobe.d/alsa-base.conf:
options snd-hda-intel model=asus-nx50
Don't forget to restart your system.. all should work fine now, no need to use other tricks like hdajackretask for example.. :-) If you're using other model in alsa-base.conf like "asus-model4" for example than you should update it too, "asus-nx50" works perfectly well with our notebook. See you around!