In almost all compression applications we use the correct compressor topology (design/type) for the task at hand. The choice of compressor type has a huge impact on how audio is processed and how it ultimately ‘sounds’. Understanding the different compressor topologies is a must for any producer. But what about how a compressor behaves? Well, for that we need to look at the two types of compressor behaviors: feed-forward and feed-back compression.
Feed-forward and feed-back compression
Compressors tend to come in two behavioural types: feed-forward and feed-back. In a feed-forward compressor the control circuit receives the audio signal before the signal goes through the amplification system. Most modern day compressor behave this way. Offering detailed control over the attack and release functions feed-forward compressors are better suited to control audio than add acres of colour.
In a feed-back compressor the control circuit receives the audio signal after it has passed through the amplifier stage. Most vintage compressors behave this way. Because the detector reacts to the signal after it is compressed the result is a smoother and more coloured response.
Using feed-forward compression to process vocals is a great way to control the dynamic range of the vocal recording but feed-back compression allows us to compress the vocals in a musical way.
In the video I use the wonderful TDR Feedback Compressor 2 to treat a female vocal take. I explain what feed-back compression is and how to use the features of a feed-back compressor to process vocals. I explain how the compressor’s parameters work and guide you through the best settings to use for vocal processing. I explain the differences between working with Peak and RMS modes and show you how each type affects the vocal take.
Plugin used in this video:
Topics covered in this video are:
- Peak, RMS and Crest Factor
- Feedback and Dynamic Compression
- Features and Control
- Best practices for Threshold, Peak Threshold and Ratio
- Time based Release
- Transient Control
- Crest and Knee
- Side-chaining and Filtering