· By Jan Branicki
Parallel Compression: An Essential Technique for Music Production
Want to strengthen your soundtrack and take it to the next level, parallel compression is what you should explore. Widely popular among sound engineers, the technique is used for creating punchy backbeats, fuller back bass, and an overall dynamic range.
In short, once the parallel compression is set up correctly, it enhances the particular elements in the mix and adds more weight and depth to it.
However, the technique can be hard to pull off, especially when you are new to it; hence most beginners struggle with the implementation. At the same time, the technique brings results even better than traditional compression; therefore, it’s worth going through all the hassle.
This article covers everything you need to know about how, why, and when to use parallel compression, so let’s get into it.
What is Parallel Compression?
Parallel compression involves mixing a dry signal with a heavily compressed version of the signal. The term was coined by Bob Kartz, who described it as upward compression, which increases the audibility of softer passages.
The technique soon became highly popular among studio engineers in NYC, hence the nickname “New York Compression.”
The technique is usually done by applying the drum bus with heavy EQ to increase the feeling of Hifi style - however, it’s not limited to only this. Sound engineers use numerous parallel effects to sculpt new tones and merge the best features of multiple sounds.
How Does Parallel Compression Work?
Parallel compression is done by routing a signal to a reverb. Sound engineers split the sound by running them through the sonic spin cycle. After that, the sound gets blended back to the untouched dry version of the sound.
In other words, the duplicate version gets dramatic treatment with effects, whereas the original version is left untouched or receives slight compression. Other than reverbs or delays, the tools used for parallel processing are routed through buses, or the sound is simply duplicated using a DAW.
Why Use Parallel Compression?
What does parallel compression do? The answer is pretty simple. When traditional compression doesn’t deliver desired results, parallel compression is what you opt for. With normal compression, you often have to compromise on the punch and dynamics. In contrast, parallel compression keeps the punch, so you get the best of both worlds.
Moreover, normal compression has other drawbacks, such as unwanted noise and broken transients. Lastly, compared to traditional methods, parallel compression gives you more control over the dynamic range - making it favorable among sound engineers.
When Should You Use Parallel Compression?
From controlling the dynamic range to adding more character to the sound, parallel compression is used for multiple reasons. Once you are clear about the why’s, you will have a good idea of when and on what sounds you need to implement the parallel compression.
The technique is commonly used on percussion, vocals, and mastering, so we’ll discuss them below.
Parallel Compression on Percussion
The no.1 reason for using parallel compression on drums is to tame the sharp volume peaks and make the percussion more robust and consistent throughout the mix.
While working with upward compression, you already work with one heavily compressed sound with very little dynamic range left. Hence to achieve the New York style compression, blend the drums for the main bus and then route all the drums through a second bus.
A fast attack time works best here, as it determines how long the compressor will take to work once the trigger is received. Additionally, the release setting identifies how long the compressor will keep working after the trigger ends.
Parallel Compression on Vocals
Some vocals tend to significantly differ in amplitude between the loudest and quietest parts of the vocal. In this scenario, multiple compressors are used on the track in series, and the technique is called serial compression.
However, parallel compression glues the sounds together and highlights low-level detail. Using a medium attack time and fast release, you can bring the natural drop in the volume and make the sound more distinctive.
Parallel Compression on Mastering Chain
Before applying parallel compression to the master track, you need to be clear about the end goal. For instance, if you want to add a punch, you should focus on transients. Here you will apply the same techniques as on the drums, i.e., a 10- 30 ms attack for sharp transients and a release setting of around 100 ms.
However, if you want your tracks to be more dense, the attack will be 10 ms, and the release will be around 50 ms.
How to Use Parallel Compression?
Here’s a step-by-step guide on how to do parallel compression.
Firstly, create an auxiliary channel for routing the sound you want to compress and add effects to.
- Next off, decide the purpose of compression. Whether you wish to control the dynamic range, add color to the mix, or glue the sounds together to make them more coherent.
- Now place the compressor of your choice on the aux channel; you may choose between UREI, dbx 160A, or Empirical Labs Distressor, as they are three of the best.
- Remember, the key to accurate compression is to set it up aggressively; hence, you must keep low thresholds and high ratios for ample gain reduction.
- As a general rule, keep a 2:1 ratio for satisfactory results, but it’s better to experiment as per your compression needs, as no two tracks are alike.
- Lastly, use the fader of the aux channel to blend the compressed sound with the original one. The more the fader pushed higher, the better the blending process. So, adjust it to a point you believe is best for your mix.
Tips and Techniques for Fine-Tuning Parallel Compression
Now that you are aware of all the basics of parallel compression, here are some tips that will come in handy.
Fast Attack Time: Consider keeping a fast attack time, as you can’t achieve the desired outcome with a slow attack time.
EQ Before Compression: It’s essential to pace EQ before compression as it stops your compressor from applying unwanted frequencies. Moreover, routing and chain order are also equally important.
Automate your Parallel Compression: If you want to create a dynamic contrast, then automate your send knob throughout the mix. Or, if you wish to create a contrast, then automate parallel compression in particular sections, such as chorus vs. verse.
Use Makeup Gain: Don’t forget to use makeup again to adjust the track volume with parallel compression. It ensures that the volume is the same as the original track.
Don’t Overdo It: Never go overboard with this technique; your track will sound flat and monotonous, losing its purpose with excessive use. So keep it subtle and skip when there is no need.
Parallel compression might sound like copying, processing, and blending the signal with the original, but it’s way trickier than it sounds. However, with proper guidance and consistent practice, you can master the technique and level up your skillset and the quality of your tracks.
Once you get the hang of the technique, you have more control over sound dynamics. It makes your sound more impactful with accurate thickness and density.
Moreover, it helps a lot in sound shaping for creative sound manipulation. Overall, the New York compression enhances the tracks and makes them sound more balanced, professional, and pleasant.