Using a mastering compressor involves applying subtle control to the overall mix to add polish, glue, and perceived loudness without crushing the dynamics.
Mastering compression is distinct from tracking or mixing compression. The goal is not to drastically change the sound of individual elements but to gently shape the entire track, ensuring a cohesive and balanced final master.
Key Principles for Mastering Compression
When applying compression to your master bus, subtlety is crucial. The reference emphasizes specific parameters for this delicate process:
- Ratios: Always stick to low ratios. The reference suggests a range from 1.5:1 up to 3:1. This range provides slight to hard compression, depending on the ratio chosen, but remains relatively gentle compared to mixing ratios (which can go much higher).
- Threshold: Use low Threshold settings. The Threshold determines the level at which the compressor begins to reduce gain. Lower settings mean the compressor is triggered by more of the signal, but when combined with a low ratio, the resulting compression is gentle.
- Gain Reduction: Aim to keep the gain reduction conservative. According to the reference, this should be not more than 3-5dB. This limited gain reduction prevents the master from sounding overly compressed or losing its natural dynamics.
Workflow for Setting Up Mastering Compression
A common approach, also suggested by the reference, is to establish the core parameters first:
- Find the Threshold and Ratio: Start by setting a low ratio (e.g., 1.5:1 or 2:1) and then lower the Threshold until you achieve the desired amount of gain reduction (within the 3-5dB range during the loudest parts). Alternatively, you might set a target Threshold first based on the peak levels and then adjust the ratio to get the right amount of gain reduction.
- Listen Critically: Continuously listen to how the compression affects the entire track. Is it gluing the mix together? Is it pumping noticeably? Is it reducing dynamics too much?
- Adjust Other Parameters (Optional but common): While not explicitly detailed in the reference, mastering compressors often have other controls like Attack and Release times. These affect how quickly the compressor engages and disengages. Setting these effectively is key to avoiding pumping artifacts and ensuring the compression enhances the groove of the track. Start with medium settings and adjust while listening.
- Apply Make-Up Gain: Once you've set the compressor, use the make-up gain control to bring the overall level back up, compensating for the gain reduction applied by the compressor. Ensure this doesn't cause clipping.
Summary of Recommended Settings
Here's a quick overview of the reference's key recommendations:
| Parameter | Recommended Setting Range | Notes |
|---|---|---|
| Ratio | 1.5:1 up to 3:1 | Stick to low ratios |
| Threshold | Low | Triggers compression gently |
| Gain Reduction | 3-5dB (max) | Keep it conservative |
By adhering to these guidelines, particularly the low ratios, low threshold settings, and limited gain reduction (not more than 3-5dB), you can use a mastering compressor effectively to enhance your final mix without sacrificing its integrity.
