Noise Gate for Vocal Cleanup

1. What is a Noise Gate and Why Use It?

When you record vocals, microphones don't just capture the singer's voice. They also pick up low-level background noise like computer fans, air conditioning hum, or faint room reflections. This is called the noise floor. While it might not seem noticeable at first, this noise can become a major problem when you start compressing and processing your vocals, as the noise gets turned up along with the voice.

A noise gate is a simple but powerful tool that acts like an automatic mute button. It mutes the audio signal when it falls below a certain volume level, effectively silencing the noise in the gaps between your vocal phrases.

To get a clear overview of this concept, let's start with a short video.

As the video explained, the primary job of a noise gate is to clean up a recording by attenuating the signal when the desired sound (the vocal) isn't present.

2. The Core Controls of a Noise Gate

To use a noise gate effectively, you need to understand its main parameters. While different plugins might have slightly different layouts, the core controls are universal. The article "Noise Gate: 12 Tips for a Clean and Natural Tone" from Mastering.com offers great, clear explanations.

Let's quickly summarize those key controls:

• Threshold: This is the most important setting. It defines the volume level. Any signal above the threshold passes through (the gate is "open"). Any signal below the threshold is turned down (the gate is "closed").
• Reduction / Range / Floor: This determines how much the signal is turned down when the gate closes. For cleaning up vocals, you often want to set this to maximum reduction to achieve complete silence.
• Attack: This controls how quickly the gate opens once the signal exceeds the threshold. For vocals, you want a fast attack so the beginning of words isn't cut off.
• Hold: This keeps the gate open for a short, fixed duration after the signal has dropped below the threshold, preventing the gate from "chattering" or closing and opening rapidly on a wavering vocal note.
• Release: This controls how slowly the gate closes after the signal drops below the threshold (and after the hold time has passed). This is crucial for a natural sound, creating a smooth fade-out instead of an abrupt, choppy cutoff.

3. Practical Application: Cleaning Vocals in FL Studio

Now, let's apply this in FL Studio. You're already familiar with the Fruity Limiter, which we used for compression. It also contains an excellent and straightforward noise gate.

To get familiar with these specific controls, let's do a quick read.

Step-by-Step Guide

Now, let's put it all together. Open a project with a vocal track that has some background noise between phrases. If you don't have one handy, you can record a short test phrase yourself, leaving a few seconds of silence before and after.

The following video is a perfect demonstration of this exact process in FL Studio. We'll use it as a visual guide while you work.

Here is a summary of the steps for you to follow along in your own project:

1. Load Fruity Limiter: Open your Mixer, select your vocal track, and add Fruity Limiter to an effects slot.
2. Identify the Noise Floor: Find a silent section in your vocal track (between phrases) and play it on a loop. Look at the meter in the Fruity Limiter; the level of the background noise is your noise floor.
3. Set the Threshold (THRES): On the right-hand NOISE GATE section, begin turning the THRES knob up. You want to set it just above the level of your noise floor. You'll see the visualizer show that the low-level noise is now falling below the threshold line.
4. Set the Reduction (GAIN): Turn the GAIN knob all the way down. This tells the gate to completely mute any signal below the threshold. Now, when you play the silent section, you should hear nothing.
5. Set the Release (REL): Play your vocal phrases. Pay attention to the end of words. If they sound like they're being cut off abruptly, your release is too fast. Increase the REL time until the gate closes smoothly and naturally after a phrase ends.
6. Check the Attack: The default attack time on the Fruity Limiter is very fast, which is usually fine for vocals. However, if you find the very beginning of words are being clipped, you may need to adjust the main Attack knob in the 'ENVELOPE' section (this affects both the compressor and gate).

4. Reference for Vocal Gate Settings

Finding the perfect settings is always about listening, but having a good starting point is incredibly helpful. The image below provides some excellent recommendations for setting a noise gate specifically for vocals.

Conclusion

Congratulations! You've now added another essential dynamic processing tool to your skillset. You've learned how to identify a noise floor and use a noise gate in FL Studio to clean up your vocal recordings, making them more polished and professional.

Key Takeaways:

• A noise gate silences a track when the signal level drops below the threshold.
• The goal for vocal gating is to remove background noise between phrases without affecting the vocal itself.
• Set the threshold just above the noise floor.
• Set the reduction (or gain) to minimum to ensure silence.
• Adjust the release time to ensure the gate closes naturally without cutting off the tails of words.

In our next lesson, we will explore another powerful function of dynamic processors: sidechain compression. You'll learn how to use the signal of one track (like a kick drum) to trigger a compressor on another track (like a bassline) to create space in your mix and achieve the classic rhythmic "pumping" effect.