One of the best features of Ubuntu that I really, really like is its ability to increase the volume to beyond 100%, and that was true for 11.10, and still here in 12.04. But my VLC player's volume is just too low in 12.04 compared to when I was in 11.10. In 11.10, I would set VLC's Application volume in the Sound Settings to almost its maximum and the Output volume to around 137%. Then I will just adjust the volume of VLC player to my preferences. But here in 12.04, once I adjust the volume on VLC player, it will also adjust VLC's Application volume in the Sound Settings. Did I just encountered a bug in my Sound Settings during 11.10 and was corrected in 12.04 or something really changed? I've tried experimenting with the audio settings of VLC but to no avail. VLC player is my default media player, since I'm pretty familiar with it already. Hope somebody can help me.
Well maybe this could help you. I had the same problem and when i found, only solution that worked for me was to install pavucontrol and correctly setup my soundcard output. Then everything worked fine. That was the case when I got no output from my sound device. I can recommend you to set up alsa and then try to set the audio setting manually
Questions about VLC might be better put to the VLC team. VLC package it for Ubuntu, but are responsible for problems on it.