What is Parallel Compression, and how to use it?

Any compressor you want to apply to the source channel, or any dynamic operation you thought of testing, will work great in the parallel channel, and I would highly recommend you to try new things because this method opens a door into deeper and subtler layers of the sound, but of great significance in the overall sound. 

Let’s take Billie Eilish as an example. I’m sure you know her, her brother produces the songs for her, and he revealed to Rolling Stone some of the methods in his mix that sound so warm and close, so, for example, the entire vocal goes through a lot of parallel processing, which gives it the warmth and feeling you hear every Her breath. 

Even instruments like bass (even a simple sub) can get interesting additions by compressing them in parallel. This is a little background on working with the method. Now let’s dive more into the specific methods.

Gentle compression

We want some kind of compression but can’t manage to do something that won’t kill the sound. Do you know the conflict? So here, parallel compression will be your saviour because the source remains clean even if you compress with a relatively strong compressor. 

You can control the level of the effect by using the correct dosage with the source channel. This will instantly give you beautiful dynamics and, on the other hand, a tight sound.
So how do we do it? 

Let’s take as an example drum (a whole kit) that has already been mixed individually and compressed individually. Now we want to give the drum group more colour from a certain compressor but are afraid that it will damage the drum sound, so, first of all, let’s break down the channel (check how to do the It’s in the mixer of your DAW, it should be very simple). 

We’ll lower the fader of the parallel channel and apply the effect we’re interested in and the parameters. Finally, we’ll gently start raising the fader until we hear the second sound as well. Here it’s your decision. How much would you like to spend?

Compression after EQ

We added EQ to compensate for some lack of sound, but because it has to be a bit extreme, it also has a negative effect in some ways. What can we do? For this, there is a compressor that will highlight the sound only in the centre of the sound and will not cause problems with other frequencies. All of this (both EQ and compressor) we must do in a doubled channel of the source. 

This way, no matter what frequency range and how much we want to raise, it will not damage the original sound but will be combined in the correct dose. 

As an example, we have a vocal that lacks a little presence in the voice, so we want to increase the 700-1kHz area, we will open another channel and route the source to it, we will apply the change in EQ without fearing the volume, and after that, we will apply a relatively strong compressor that will keep it only in the right place. Without delay in the attack and with a relatively smooth release.

Punchy sound

Again, we want to make a sound stand out in the mix. Still, directly on the sound, we have to apply a compressor with a long delay before attacking will affect the rest of the sound in a wrong way, and we may need to get a better result. Let’s demonstrate this on a kick.

 We want it to be more punchy but still have a stable body. With parallel processing, we can do it without a problem, and it has a beautiful effect on the sound.

Optimisation for small / bass-less speakers

You know that when you finish a mix and you go to listen to it on a different system, from personal headphones, your car, and the television. Still, unfortunately, it doesn’t sound as good as it did in the studio. Usually, the big problems are manifested in the low-end lack of bass/too much bass, and we need help fixing it! ,Parallel processing can be your saviour.
Try the following steps if you are missing bass:

• Duplicate the channel of the bass in question.
• Apply an over-drive effect or any distortion you like, but very gently.
• Put a relatively fast compressor after it with average compression
• Start raising the fader and see the magic.

In two words, what we did here: So, in medium to small speakers, the bass area is almost completely absent, compared to the middle range, which dominates this type of speaker. That’s why we took a harmonic enrichment that will give us a little more aggressive midrange so that the bass will stand out even in smaller systems. (Note that you check this in the Normal sound system That doesn’t sound too distorted).

Vocal presence

Sometimes, we want to make the vocal feel more central and controlling, but we can’t get good results on the original channel, so we can do it on a separate channel. We can do compression in combination with EQ or compression alone. It doesn’t matter because every action we do on The replicated channel will only have a partial effect, so of course, you have to learn how to apply parameters subtly even if you do parallel compression, but still, everything will be more doable.
Here are simple steps to get tighter vocals:

• Duplicate the original channel.
• Apply a compressor with a long attack delay, quick release, and a relatively still threshold.
• Apply EQ before, with a boost in the 1.5 – 2.5kHz range, to make the sound stand out in the mix (optional).
• Start raising the volume of the channel