I had the same problem (also running on a Dell Studio 16 XPS - 1645). I fixed it by adding the following line to /etc/modprobe.d/alsa-base.conf, then rebooting
options snd-hda-intel model=dell-m6-dmic
People with other Dell Studio models, eg 1435, reported success with:
I had the same problem (also running on a Dell Studio 16 XPS - 1645). I fixed it by adding the following line to /etc/modprobe. d/alsa- base.conf, then rebooting
options snd-hda-intel model=dell-m6-dmic
People with other Dell Studio models, eg 1435, reported success with:
options snd-hda-intel model=6stack-dell
(see http:// linuxforums. org.uk/ ubuntu/ internal- mic-not- working- in-my-ubuntu- 10-10-% 2864bit% 29-in-my- dell-studio- 14/)