Stereo Tool

If it says "it doesn't do much" then most probably your preset is not delivering enough audio for it to do it's work, meaning the level "drops" above 0.

For AGC to function, it needs a certain "supply" of excess volume which it can work on. AGC - kind of - swallows it, so that it can hold or release volumes in whichever way it was programmed to do so in the settings. In your case, increasing Drive by anywhere between 6 to 12dB will most likely do the trick!

Thanks. I do not know if you saw the picture (the link in my post)

But AGC graph shows activity bet -6 and -12 DB -- i figure it means it is pumping ?

Drive +8
Target -12

Don't get it it

I saw it, and frankly -6dB is pretty low, at least for me. It means, that the module has a 6dB of volume "stored" in case it drops by exactly that amount. That's not much. Very often times music will drop way below that, and that's probably when you get your message. I myself try to set it so that the song verses oscillate between -12dB and -18dB, with choruses reaching -18dB (they are louder, so AGC "swallows" more excess volume for itself). It means that when the bridge, or any other transition kicks in (the level of input track drops), I have coverage of volume for 18dBs relative to the loudest point of the track (so that it can always keep steady volume for the next processing step, which is multiband compressor). This is, of course, very subjective, depending what result you want to achieve!