Bus Compression vs. Mastering Compression
Compression on individual tracks behaves differently than compression on a whole mix. Learn how mastering compression works, what "glue" means, and how to avoid over-compressing your master.
What Does Mastering Compression Do?
When mixing, compression is used to tame dynamic instruments (like a vocal or kick drum). In mastering, compression is used for bus compression, applying a tiny amount of gain reduction across the entire stereo mix to bind all the elements together.
Engineers often call this effect "glue".
Key Settings for Beginner Mastering Compression
- Low Ratio (1.5:1 or 2:1): Keeps processing subtle so you don't squash the music's natural dynamics.
- Slow Attack Time (30ms – 100ms): Allows the initial punch of drums (transients) to pass through cleanly before compressing.
- Auto or Smooth Release Time: Helps the compressor breathe naturally with the tempo of the song.
- Subtle Gain Reduction (1 dB to 2 dB): You should barely see the meter moving. If the needle is constantly pinning down 4–6 dB, you are over-compressing!