ac3 encoded sound

[GEOHF]

Hello everyone . here is my problem :
I encode dvd in avi without the sound , then with ac3 version virtual dub i mix the ac3 file sound (that i have ripped) with the avi .
The result is an avi with 5.1 sound as wanted
BUT !!!!!!!!
The quality of the 5.1 sound and also the volume when the avi is played is not as high as the original , and when i say original i mean the ripped ac3 file that i have tested and sounds fine.
PLLLLLLLLease help , Can't i make a avi (DIVX) with 5.1 sound with the same sound quality (like dvd) ?
The Problem is with Virtual Dub ?
I Am losing my mind trying to think what goes wrong but i can't

[BoF]

I see 3 solutions:
1. use besweet to normalize your ac3 (via boost)
2. use ac3filter to perform a realtime compression while playing. more information in this thread you would have found doing a basic search in digital-digest forum.
3. use besweet to normalize and transcode to ogg vorbis (via boost)