I had a this problem with 12.04 when it came out and posted my question here, wich was linked to another question with the solution (for me, not for the other guy). I can't find any of those now.
Ubuntu 12.10 volume doesn't work until it is increased to 25-30%, just there I can hear the minimum. With alsamixer, increasing volume with laptop keys, the Master goes to 18, then to 24 only there, the Front starts increasing from zero, which is why there is no sound at all in levels below 30%. This was solved back then adding a line to a .conf file as explained here: https://help.ubuntu.com/community/HdaIntelSoundHowto and here: Volume range is narrow in 12.04 But I can't find what line I added as those questions are not here anymore (already searched) I have the same problem as here: Volume control 'out of phase' with actual volume and Alsamixer But none of the solutions posted solved my issue.
CODEC IDT 92Hd90BXXX