Created attachment 198331 [details]
ASUS N550JX external sub-woofer doesn't work out of the box. In order correctly register sub-woofer node with ALSA, pin change patch is required:
0x10ec0668 0x104313df 0
Attached alsa-info.sh output is generated from patched and working system.
Could you try the patch below?
Created attachment 199411 [details]
Test fix patch
Do hdajacksensetest -a report the jack state of the external subwoofer since other asus n. Series laptop using alc668 can detect the subwoofer?
(In reply to Takashi Iwai from comment #1)
> Could you try the patch below?
Yes it works. Thank you.
I queued the patch now. It'll be included in the next pull request for 4.5-rc1, and backported to stable kernels eventually later.