how to normalize ac3?

[Acid]

i ripped audio with virtualdub and recompressed the ac3 with AC3Machine at 320kb/s, after i merged it back to the video with nandub, when i play the final avi sound is very low compared to the original, how can i normailize it or something??
when i am trying to use volume option in nandub it gives me some error...

Acid

[setarip]

When using the AC3Machine, try altering the "Gain" settings in order to increase overall volume...

[Acid]

could you be a little bit more specific? this is my first time i encounter something like "gain".... what is actually gain values nad what values would you suggest I should try?

[setarip]

Experiment and make discoveries ;>}

[Acid]

ok ) the volume is ok now but it sounds somewhat crispy comparred to the original... what do i do about that?

[setarip]

Once again, experiment with things such as automatic gain and normalization...