Are You Listening? Ep. 3 | Compression in Mastering

Key Takeaways

• Compression is often heard by its absence rather than presence, making it one of the hardest audio tools to learn and train your ear for.
• Not every mastering session needs compression; the best gain control is often simple fader riding, which avoids artifacts and coloration.
• In mastering, heavy compression fails because the mix is fully baked; subtle use can manage relationships between elements or smooth section transitions.
• Compressors differ from limiters by working with longer timeframes, making them better for shaping musical dynamics and sustain in both mixing and mastering.
• A common myth is that compressors make things louder; they actually turn signals down, and perceived loudness comes from subsequent gain increase.
• Compressors can rob early harmonics (1–4 kHz), reducing perceived loudness unless fast release times or distortion circuits are used.
• The key trade-offs in compression are between transient and sustain, and between clarity and density; longer attack times preserve clarity.
• Sidechain compression in mastering often uses a high-pass filter to hide the compressor's action, creating transparent smoothing rather than audible pumping.