I recently switched from 11.10 to Ubuntu 12.04 and my headphone jacks have stopped working and my speakers now have extremely low volume. I have no clue what to do. I have a Dell Studio 17/1749 with an hda intel sound card, JBL speakers and a built in subwoofer. The subwoofer does not play sound at all and the two front internal speakers play at around 60% of their normal volume when turned all the way up. Also, my microphone does not work. I have been trying to figure this out for quite sometime and still have yet to fix anything.