It took me a long time to figure out, but I realized that some of my mp3s and wavs were playing very quietly, and some normally. All of my sound levels are set correctly (I tried multiple mixer programs). Finally I realized that it is all the mono sound files that are playing so quietly while stereo ones are playing normally. The same behavior is seen in lots of different audio players (mplayer, audacity, amarok, etc.). I have kubuntu 12.10, a brand new ASRock motherboard with H77 chipset, ALC892 sound. What can I do to make the mono files play at the normal level. Even with all the volume levels turned up I can't really hear them. Thanks!