Envelope Follower or Ducker?

[Trebor]

I would like to have a music (foreground) and have speech (background) that is always X (lets -15db) below the foreground music. I think duckers are used just the opposite, where people generally want the music to lower but I want the speech to stay lower than the music.

Usually people duck the music with the voice, but you can duck the voice with the music if you want.

Audacity has a native Autoduck, alternatively Steve made a “dynamic mirror” plugin which can duck or follow.