Compression is an important tool. When it can be challenging to grasp, it can enhance a recording or ruin it. It has so many uses. It's challenging to know where to begin when describing it. If you have one thing to remember about compression, understand that its main function is to control dynamic range, which is the difference between the loudest and the quietest sounds in a recording.
So what is compression? Well, you can think of it like a tiny engineer who's constantly riding the faders to adjust the level, so that there's consistency across an entire recording. Compression settings determine how active that tiny engineer is well keeping the dynamic range and check. Compression works by reducing the loudest sounds so that they fit into a smaller dynamic range. The result is that there isn't as much contrast between the loudest and the quietest sounds. There's more consistency in the level, and a quieter parts can come true.
If we raise the level of a track, so that the quieter parts are heard it's possible that the loudest parts might go into distortion, so compression can be helpful, in managing the differences. This is also why compression is associated with making truck sound louder overall, but it's actually doing this by reducing, or compressing the louder sections to manage the difference between loud and soft.
In mixing we can use compression to shape individual sounds so they blend and balance together, and example, would be for vocals when the vocal has certain words or phrases that are louder or softer than others, it can be hard to fit them into a mix with out some words sticking out in other words getting lost.
In mastering, we can also use compression to shape the tone for various effects. We use words such as punch, or glue, or pumping to describe these effects. Using compression in mastering, we can also suddenly adjust the balance between the rhythm section, melody, and harmony.
It takes practice to decide whether you need to compress your audio, and how to dial in just the right amount. When mastering the right amount is related to the way that the audience will listen to the audio, combined with consideration of musical style. Some styles want more dynamic range than others. For example a podcast that people might enjoy on earbuds while riding the subway or driving in their cars might need more compression to be intelligible and the noisy environments, weather forecast recording that people will enjoy in the quiet home environment, might need a little or no compression, so that it maintains all the impact and energy the dynamics in the music provide.
We might make different judgements for different styles, but the basic concern is the same across all of them. That the listener get enough dynamic range to feel the impact of the audio, but not so much, that they have to adjust their listening little, and our course will explore many different aspects compression, We hope you enjoy them.
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