Some people argue that compression isn't necessary for a good mix. They're wrong.
It's just not that simple. In some lighter genres, yes, that statement would apply. But when it comes to rock music it couldn't be further from the truth.
Rock music needs to sound aggressive. It needs energy. It needs to be LOUD. If you want your rock mixes to sound like rock mixes, you need compression. And that's the truth. Observe any well-know mixer in this genre (Chris Lord-Alge, Andrew Scheps) and you will see that compression is synonymous with rock music.
When it comes to rock music, there is one particular application of compression that's vital: the lead vocals. In most cases the vocals are the most important element of the mix. If the vocals sound wrong, the mix will sound wrong. It's the focal point of the entire song for most listeners. Get the vocal mix right, and everything else will fall into place.
In this tutorial I'll show you how to compress rock vocals to sound punchy, aggressive and full of energy.
Why You Should Use Compression on Vocals
Before I move onto strategy and the simple three-step process, let's take a step back. Consider the goal. Consider what it is you're aiming to achieve with compression.
There are two distinct reasons why you need compression in your mixes, and both apply here. The first reason is to control tone, and the second reason is to control dynamics.
Compression is synonymous with rock music because of it's tone shaping abilities. By varying the attack time on the compressor you can radically change the tone of a vocal.
By using a fast attack time you'll clamp down on the transient (the onset of each word). This has the effect of making the vocal sound thick and heavy. By clamping down on the transient, you're essentially reducing the aggression and attack of every word.
In some genres, this might be desirable. Be careful, though. Using a fast attack time can easily lead to an over-compressed, lifeless vocal. In rock music this is the opposite of what you want.
Instead, by using a slow attack time, you'll clamp down on the vocal while leaving the transient and the attack of every word intact. The more you clamp down with the compressor the louder the transients appear to be, as they are slipping through the compressor before it has time to react.
Think of attack time as controlling attack amount. As you move the attack knob from fast to slow, you're turning up the attack and aggression of the vocal.
When mixing rock music, use slow attack times to add energy to the vocal. This has another hidden benefit: the vocal will now poke through the mix more easily, as the transients now appear to be louder.
There is another reason why compressing vocals is vital. As the focal point of the song, the vocal needs to be loud and clear. In most cases, you want every lyric to be audible.
Yet the human voice is a naturally dynamic instrument, a vocalist can go from a whisper to a shout within the same song.
To make the vocal sound professional and finished, heavy dynamic control is needed. In pop music this is best done with automation. But when it comes to rock music you can lean a lot more heavily on compression to control the dynamics for you.
Some automation will always be necessary but there is no need to automate every single word.
Instead, use two or three compressors on the same vocal, to reign in the dynamics, and create a performance that maintains a similar volume level. This is called serial compression and it's generally better than relying on one compressor to do all the work.
Compressing Rock Vocals in 3 Simple Steps
Step 1, Apply Automation
Before you apply compression scan through the vocal and check for any particularly loud or quiet sections. If you find any, automate the gain instead of the volume. This way the vocal is more consistent before it hits your compressor.
You can do this in a number of ways:
- Add a trim plugin to the first slot and automate the level
- Automate the clip gain by creating a new clip or region for that section and manually adjusting the gain (you can use the Clip Gain feature in Pro Tools to do this)
- Automate the volume fader and then change the output to a new channel where you will add your processing and compression. This is my preferred approach
Step 2, Dynamic Peak Compression
With this first compressor you want to catch the louder peaks before using a second compressor to shape the tone. To do this you'll need a higher ratio, fast attack time, fast release time and a higher threshold.
Start with the ratio set to 4:1 and set the attack time to the fastest it will go. Bring down the threshold until you notice that the compressor is only clamping down once every few words.
Remember, fast attack times have numerous downsides, so all you want to do here is catch the loudest peaks.
Step 3, Constant Tonal Compression
Now that the vocal is more consistent after some automation and initial compression, you can dive into tonal compression and start shaping the tone without overloading the compressor.
Load up another compressor, and this time dial in a slow attack time. Around 10ms works well, a low ratio (2:1 or less) and a medium attack time of 50ms or above.
The aim with this second compressor is to have it constantly engaging and disengaging, so lower the threshold until you see 6-10dB of gain reduction being applied every word or so.
If you apply these three steps every time you mix a rock vocal you'll soon find that it doesn't take long to make a vocalist sound loud and punchy.
Once you have the vocal down, focus on the mix buss, kick, snare and bass next. Liberal compression will help you to create high energy mixes, just remember to stick to slow attack times.