After upgrading from 13.04 to 13.10 Dell's Inspirion 17R subwoofer stoped working.
In Ubuntu 13.04 was workaround by adding in the file
/etc/modprobe.d/alsa-base.conf next line:
options snd-hda-intel model=ref
This issue was discussed here: How to activate subwoofer in Inspiron 17r?
After update previous workarounds don't help and I get no sound from any speaker in this case.
Is there some other fix for the latest version?