Comment 13 for bug 1332900

you cannot use dynamic reconfig(apply now) if you are not using debugged version alsa driver

you need to use set as boot default which use early patching and require reboot

you can just add the subwoofer only

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda/patch_realtek.c?id=73bdd597823e2231dc882577dbbaf8df92fe1775

+ [ALC668_FIXUP_DELL_MIC_NO_PRESENCE] = {
+ .type = HDA_FIXUP_PINS,
+ .v.pins = (const struct hda_pintbl[]) {
+ { 0x19, 0x03a1913d }, /* use as headphone mic, without its own jack detect */
+ { 0x1b, 0x03a1113c }, /* use as headset mic, without its own jack detect */
+ { }
+ },

is there any reason add two pin complex when only headset mic is needed for dell laptop?

this create an useless pin complex headphone Mic