I’m currently trying to replicate the effect that the “Smart Volume” setting of current Sound Blaster cards applies.
It seems to be a compressor but I’m not sure what the settings would look like. It seems like it has a lot of make-up gain.
Please see this image for a comparison of a sound file. The upper track is recorded with “Smart Volume” enabled, the lower track is the original. I was not able to align them perfectly, unfortunately. But the difference should be visible across most of it.
Any ideas?
Yes that looks like a form of compression - probably closer to an “AGC” (automatic gain control) effect (like the automatic audio recording level in video cameras).
Your screenshot does not show the time scale, so I can only guess about that.
Here is the “before and after” using Audacity’s “Compressor” effect:
I’ve attached another screenshot to this post with the timescale included.
Increasing the release time to 10 seconds and increasing the threshold to -50dB looks a bit better, too. However, it’s still a bit off… but this is an excellent start, thank you.