What is a compressor? How can I use it on my FlashTrack?

You’ve probably heard many times that “an audio compressor is a staple in music production,” but chances are you haven’t had the opportunity to take a few minutes to understand how it works. Here, we’d like to take that opportunity to walk you through some important concepts, using actual recordings captured by FlashTrack, so you can gain a better understanding of what a compressor is and how to use it effectively.

An invention rooted outside the recording world

The first compressors were invented to address challenges in telephone lines and then radio broadcasting, mainly to manage the audio peaks in radio transmitters. These peaks at that time, could result in overmodulation, causing distortion that damage speakers. Therefore, an equipment that can control the dynamic range of the audio signal was invented.

Over time, music producers discovered the potentials of compressors, realising they not only could gain a refined control of the dynamics, but also add warmth to the tone. The solution initially for a stable radio signal has become an essential tool in the world of music.

Understanding Compressor Parameters

Now that we know why compressors were invented, let’s talk about how they work in practice. Compressors come in all shapes and forms—vintage vaccum tube units, modern digital plugins that rely on digital signal processors. Although the models may have tonal differences, they all share the same core parameters to control the dynamic of your sound.

1. Threshold – When Does Compression Kick In?

The threshold sets the volume level at which the compressor starts working.

• If the audio signal goes above the threshold, the compressor reduces the volume.
• If it stays below the threshold, nothing happens.

Here, we can see how the signal was captured by the FlashTrack. We used a speaker to play a certain music in a constant volume to avoid unwanted dynamic changes.

And here’s the result when the compressor is off. You can see that the signal often goes beyond the center -12dB mark.

When we enter the my compressor screen, we first can adjust the threshold to decide when to let the compressor kick in. Here we set the threshold in -13db, which means the compressor will start hold back the volume whenever the volume exceeds -13db.

You can see the from the signal bar that it’s more even and the loudness is tamed a little.

2. Ratio – How Much Compression?

The ratio determines how much the signal is reduced once it crosses the threshold.

• A ratio of 4:1 means that for every 4 dB over the threshold, only 1 dB gets through.
• Higher ratios (like 10:1) act more like a limiter, preventing peaks from getting through at all.

👉 Tip: For instruments like saxophone or guitar, a ratio between 3:1 and 6:1 is often a good starting point.

In the video above, the ratio was 4:1. As a contrast, we occassionally set the ratio to 12:1.

And let’s hear how it sounds.

It sounded less louder in some parts, didn’t it? But you might also have a feeling that the sound started to become less natural. The higher the ratio, the less dynamic range you’ll get. That also will lead to the reduction of attack and punch.

3. Attack and Release – How Fast Does It React? How Long Does It Hold On?

The attack time controls how quickly the compressor tame the signal to the target level when crossing the threshold.

• Fast attack clamps down on the sound immediately, which is great for controlling sharp transients (like drum hits).
• Slow attack allows the initial punch of a sound to come through before compressing.

For natural instrument dynamics, try a slower attack to preserve the initial punch of the sound.

The release time controls how quickly the compressor bring back the volume to a certain level after compression.

• Fast release sounds more aggressive and punchy.
• Slow release creates a smoother feeling.

If the release is too fast, you might hear a pumping effect. If it’s too slow, your sound could feel squashed.

To create an extreme example, we set the attack time in 10ms, and the release time in 100ms. Also the ratio was 32:1.

Let’s hear how it sounds.

Under this setting, the signal was very costant in stregth. Whenever there’s a strong peak, the compressor will activate and compress the signal, therefore keep it under the -12dB mark. However, when we compare the sound of the recording, it may sound a bit dull and lack of dynamic than the original one. You can also hear the sound was squashed if we set a relatively high ratio and short attack time. Kindly remind you that this radical setting is used for demonstrating only, we don’t want to get roasted by the producers.

4. Gain (or Makeup Gain) – Bringing Back the Volume

After compression, your overall signal may sound quieter. Makeup gain allows you to bring the volume back up to a desired level without affecting the dynamics you’ve just shaped.

Presets or my user-defined settings?

After going through these parameters, some may ask what should they use? Cloudvocal team based on their experience, set various presets such as:

• CAST+ : Optimised for recording podcasts and voice-over. The goal is to ensure the vocal is clear and not to clip in sudden laughters.
• PUCNCH+: Optimised for adding puchiness in the recording. By tweaking the attack and release time, we can emphasize the punch.
• SING+: Optimised for singers.
• DYNA+: Optimised for instruments that have strong dynamic. This preset will make them sound smoother.

However, if none of the above fits your need. You just simply go to the my comp page and long press the COMP button to adjust you own settings. This setting will be saved in the memory of FlashTrack.

Have fun trying these settings and feel free to share your experience with us in the comments.