Seems normal, as you shouldn't exceed 0dB
And try using this formula
20*log10((VolumeSFX/10)*(VolumeMaster/10))[/code:2un9or2m]
Where VolumeSFX and VolumeMaster are two global variables, so you can have a master volume that would control SFX, Music, Background noise, and a SFX, Music, Background noise variables so you can turn each part down independently.