Audio gain settings for VCD/SVCD

[Pix]

The online manual indicates :

Allowed values are 0..10 for mencoder engine, and -96..+96 dB for mpeg2enc engine. Not used by ffmpeg engine.

Now I understand why I never heard any difference as I was using the values 0-10 for SVCD/VCD. My question : what is a "fair" value, knowing that most DVD rips have a very low sound level originally.
I would like to increase the level, but not so much that it will distort the sound. And as I have no idea what -96/+96 db represent, I have doubts.

Then better ask than test and wait each test to finish the encoding

[major]

It really depends from your source, so you need to make a test. I suggest to always keep small source clips (10 seconds or so) so as to quickly test different encoding options.