I am looking for an Automator action (or an app with Automator support) that can adjust the volume on audio files (something like set to 150% of input file volume), preferably free.
- Volume/level effects
- vol: Adjust audio volume
According to the SoX documentation, the following should double the volume of
input.wav and write it to
output.wav (the value after the -v flag is a multiplier)
sox -v 2.0 input.wav output.wav
You should be able to use this in an Automator workflow using the "Run Shell Script" action.