Getting the right compression setting for vocals will go a long way in how well your music will sound.
An incorrectly compressed lead vocalist, or overly compressed backing vocals, can seriously hurt an otherwise excellent creative masterpiece.
So in this post we’ll go over a few compressor settings to use when you’re recording and mixing vocals in your studio. Keeping them in mind will help you to stay on the right track.
Let’s begin 🙂
Table of Contents
- The Basics
- Vocal Types
- Final Thoughts
Read the other compression guides:
- Compression Basics
- Vocal Compressor Plugins
- EQ and Compression for Drums
- Compression Settings for Bass
Let’s Start with the Basics
What is a compressor?
A compressor condenses the louds and softs of an audio signal. Loud sounds get reduced in volume while softer sounds get raised. Compressors are super-useful devices for smoothing out volume spikes while also giving quieter sounds more punch and presence. Most music heard today contains compression, particularly on vocals. Compressors are a indispensable part of recorded music.
How does a compressor work?
We use compressors to make changes to the sound’s amplitude (volume). Usually to make it more punchy and louder in the mix.
Compressors allow you to fine tune a few key settings in order to control changes to both the amplitude and time of the signal as it passes through. All of those knobs on a compressor have different duties. Let’s look at what some of these knobs do.
The threshold knob is a gatekeeper. When it’s set to 0dB, the full signal is allowed through unchanged. But as you turn it down towards negative infinity, more of the audio gets attenuated or quietened.
So, let’s say our threshold ‘gatekeeper’ allows everything under -12dB through to the next stage. What happens next? Well, any audio above -12dB is then due to be compressed. How compressed? That depends on the ratio. Ratio is the strength of the compression. For example, 2:1 is considered gentle compression, while 8:1 is considered extreme.
Attack and Release
The attack and release parameters are concerned with the time window during which the compressor is active. Both attack and release are measured in milliseconds (ms). Changing the attack will change how quickly the compressor kicks in and begins reducing loudness.
Release uses the same principle, but applies to the end of the incoming audio rather than the start. A release value of 0ms means that the compressor will stop working very suddenly after dipping below the threshold. At higher values, it would sound like a volume knob is gradually turning down the audio.
Knee and Make-Up Gain
A knee is also a time control. It controls the suddenness with which the sound is compressed as it approaches the threshold. A softer knee means a smoother sound while a harsher knee means more abrupt changes in volume as the sound dips and jumps around the threshold value. If the compressor is kicking in too noticeably, soften the knee.
Gain is the most simple and common parameter in audio processing. Remember, a compressor typically makes loud sounds quieter and more consistent. It reduces spikes in the mix. As a result, the overall sound is usually quieter after passing through a compressor than before it entered. Make-up gain simply allows you to turn it back up to match the levels in the mix.
You can read more about how a compressor works from this article we posted a while back.
Different styles of vocal delivery and range will require different settings, right?
Generally speaking, the more mainstream the music style, the more compression you can use.
Older or less mainstream music tends to preserve the dynamic range (louds and softs) of different moments in the track.
The important thing is to be deliberate in your mixing. In other words: know what you’re working with.
Knowing what style you’re aiming for before beginning to apply the different compression setting for vocals in various styles will help keep you on the straight and narrow path toward a good mix.
Let’s look at a few of the more common ones.
Lead vocals in pop and mainstream music are the centre point of the mix. Compression settings for lead vocals should be as natural sounding as possible.
Because humans are expert listeners, any small unnatural-sounding volume jump or dip will be noticeable and detract from the power of the melody and lyrics.
If the song’s central focus is the lead vocal, the goal is to make it sound like you’re in the room (or hall) with the singer and avoid any extreme effects.
Standard compressor settings for lead vocals
- Threshold: –9dB
- Ratio: 2:1
- Attack: <1 ms
- Release: About 50 ms
- Gain: Match the input level and output level. Don’t use the compressor to boost the volume.
Backing vocals should be thought of more as instruments than vocals. A general rule is to apply just enough compression to distinguish them from the rest of the mids, but never so much that they overshadow the lead vocal.
The interlude from Knights of Cydonia by Muse is a great example of terribly overcompressed backing vocals (even though it kind of works for this context).
In group singing, however, it’s appropriate to treat all the vocals as lead vocals and give them identical compression settings.
The cover of Bohemian Rhapsody by a capella group Pentatonix is an example of this.
Standard compressor settings for backing vocals
- Threshold: –4dB
- Ratio: 3:1
- Attack: <1 ms
- Release: About 40 ms
- Gain: Match the input level and output level. Don’t use the compressor to boost the signal.
Rap is a rhythmic genre of music. Focus is placed on the percussive characteristics of the delivery.
In general, faster compressor attack times will lower the level of consonants. The effect is that the vocals sound smoother and less aggressive.
Slower attack times, on the other hand, will emphasize consonants. This is good for the spitting, popping sounds of rap and hip hop vocals, and adds articulation to a recording. As we said when choosing a good microphone for rap, clarity of diction is key here, and slow compressor attack sounds will help to achieve that.
The ratio is generally pretty high to ensure that weaker syllables don’t get lost in the mix.
Standard compressor settings for rap vocals
- Threshold: –5dB
- Ratio: 4:1
- Attack: <60 ms
- Release: About 40 ms
- Gain: Add 2dB to allow the compressor to color and thicken the overall sound
You can learn more about mixing rap vocals in general from this helpful article at Pro Audio Files.
These guidelines should help you to find a starting point for compressing your vocals. But remember to use your vocal compressors on a case-by-case basis.
It’s also important to get familiar to various styles of music by listening critically to how the vocals sound. Listen listen listen to as much as you can. Your ears should guide you to letting you know what sounds good, and therefore what goes into mixing good music.
Using the guidelines provided in this post will help you to hear the difference, and will then help you make more intelligent decisions when dialing in your compression settings.
Go forth and compress!