ESSENTIAL RECORDING TECHNIQUES - Compression

An introduction to COMPRESSION, what it is and why it is used with audio files to ‘even out’ the dynamic range during playback.

We look here at the definition of THRESHOLD parameter and how it is set with audio files that contain differing peak levels.

We now look at the relationship between the THRESHOLD and RATIO options and how they are linked.

In tandem, the threshold and ratio parameters work together to compress gently or aggressively.

The gain reduction meter helps us visually understand how much compression has been applied.

This is how we return the compressed output volume to its original pre-compressed input level.

The Attack and Release parameters allow us to adapt the speed at which compression occurs and for how long.

Without any narration, we see and hear examples of the parameters previously discussed on a drum loop.

The knee parameter refers to how the compressor transitions between non-compressed and compressed states.

Set to hard knee compression, the gain reduction applied to the signal occurs as soon as the signal exceeds the level set by the threshold.

By contrast, utilising soft knee compression, the onset of gain reduction occurs gradually after the signal has exceeded the threshold.

The gain reduction scale allows us to zoom in more closely and see the effect of light or aggressive compression at appropriate zoom factors.

Using Artificial Intelligence compressors accelerates the setting up of compression parameters.

Here, we are introduced to the concept of upward compression as a contrast to the more traditional downward compression.

This is an explanation of the difference between upward and downward compression.

With every live recording, there will be low level background ambience or noise. Here, we look at the issues the ‘noise floor’ can introduce when using upward compression.

We now see Pro MB in action on a vocal file.

The use of expanders allow us to increase the dynamic range of a signal by making the quietest points further away from uncompressed loudest peaks.

Here we use a single band expander to help reduce a noisy recording and isolate the vocal component.

Tube compressors are long regarded as being able to introduce a welcoming warmth to the audio fed into them; a warmth long thought digital compressors struggled to achieve.

Here we look at a type of compressor called a limiter.

Here we see Steinberg’s functional simple limiter in use on a delicate piano track.

For more complex limiter options, you can use Fabfilter’s Pro L2.

Parallel compression allows us to ‘thicken’ the sound of an audio file. Here’s one way of doing it.

Here is how to using 'fader riding' in a DAW to achieve a natural sounding compression.