FAST Q&A — FAST Compressor


Get to know how and when to use FAST Compressor

We dive deeper into FAST Compressor and explore why and when to use the plugin and compression.

Q: What is compression, and why is it used when producing music?

A: Sound doesn't have a constant or singular volume; instruments have quiet and loud parts. For example, the guitar will have the attack of the string, accents on chords, and the sustain of notes, with vocals behaving similarly. There will be big transient elements to ghost notes on a snare which add to a groove, but are much quieter than a full snare hit.

A compressor reduces the dynamic range and the gap between the low and high volumes (perception of loudness). In a really dynamic vocal, low volumes will get covered up by other parts. Compressing that signal makes mixing easier as there are less drastic volume changes — it’s impractical and time-consuming to go into your DAW and automate volumes across your vocal track. You would then need to retroactively do this each time you changed any volume on another track — a nightmare.


Q: What is a Knee in compression? What does it do?

A: The Knee tells the compressor how fast to compress a signal once it passes the threshold. The threshold is the point at which you want to affect the sound, so when a signal exceeds that, the compressor will take action to lower that volume but leaves everything below. Essentially, the Knee affects speed, which will vary from instrument to instrument due to their natural attack and release. FAST Compressor’s visualiser shows this so you can see how it behaves as you higher or lower the Knee value. It’s great to learn and match what you see with what you hear.

Q: So that’s the Knee; what does ratio refer to, and how does that affect the sound?

A: Compressor ratio is how much gain reduction is applied once the signal exceeds the threshold. So do we want an aggressive compression or just a little? For example, a ratio of 4:1 means that for every 4dB (volume measurement) the signal rises above the threshold, the compressor acts on that amount. The greater the ratio, the bigger the number and the more compression is applied to the signal.

Focusrite has plenty of experience making compressors, notably the Focusrite Red 3, and the ISA 130 - found in high-profile studios around the world. With the powerful AI in FAST Compressor, it is a great way to experiment with the various controls to see — and hear — how each of the elements affects the audio signal. Many plugins and hardware compressors will simply have a signal strip that displays the volume; with this, it can be hard to understand what is going on with the effect.

FAST Compressor, with its powerful AI adapting settings and the graphic visualiser, will help you better understand compression and feel more confident when using it. After all, compression is the most commonly used effect when mixing and mastering — there’s no escaping it if you want a professional-sounding mix.

Try FAST Compressor for free and experience first-hand the state-of-the-art AI plugin that dynamically balances your voice and instruments instantly. If you’re a Focusrite or Novation registered hardware owner, get 30% off your purchase. This discount is also available for FAST Bundle.

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