What Is Parallel Compression & 3 powerful ways to use it?
Parallel compression — or New York style compression— is a popular mixing technique invented by Dolby A in 1965. This slighty different way of using compressors can provide your sounds with a sense of weight and power without sacrificing natural dynamics and punch. Parallel compression involves heavy compression on one of the mixers parallel buses. It is an effective method for achieving professional-grade results in your recordings. It is often used on the Drum Bus or Vocal busses, but not there is no right or wrong. So get creative!
How to create Parallel Compression?
Parallel compression involves blending the original dry (uncompressed) signal with the processed (Parallel compressed) signal. This technique allows you to preserve the original dynamics of the sound, even with aggressive compression settings unlike using the normal compression technique. By mixing in some of the dry signal, you can achieve the desired level of compression without compromising the natural dynamics of the sound.
You can use any compressor you own for parallel compression if you set it up correctly. Here’s how:
- Create an aux return channel in your DAW’s mixer. Make a mono return track if your source signal is mono and a stereo return if your source signal is stereo.
- Add the compressor plugin as an insert on the aux return track.
- Create a pre-fader send on your source track to route to the compressor on the aux. If you use a post-fader send, changing the level of the source’s channel fader will also affect its level at the compressor’s input—causing your compression to change!
- Select the send from your source as the input of the aux track
- Dial in your compressor settings for parallel compression
- Tailor the mix of dry and compressed signal by adjusting the fader level of the wet and dry tracks.
Parallel Compression for Mastering
Parallel compression is also commonly employed in the mastering process. However, it’s essential to determine your desired outcome before making any adjustments to the master track or stereo output.
If your goal is to add punch and dynamics, it’s crucial to maintain the transients’ integrity. This can be achieved by employing the same settings as parallel compression on drums, such as an attack time of 10-30 ms for sharper or snappier transients, and 30-100 ms for punchier, heavier sounds like kick drums. The release setting could be approximately 100 ms, but it’s recommended to experiment with different settings to determine the best fit for your track. Trust your ears!
On the other hand, if you’re looking to increase the track’s density, you’ll need to use shorter attack and release times than the previous settings. However, it’s generally recommended to avoid going below 10 ms (attack) and 50 ms (release). If the sound is distorting, reduce the compression ratio slightly, even if the transients require more compression.
Prevent latency in digital mixes
When using busses in digital mixing, it’s crucial to account for latency in your DAW. Traditional analogue routing paths for parallel compression can cause signals traveling through parallel pathways to arrive at the mix buss at different times, resulting in undesirable comb-filtering and phasing effects. To address this issue, it’s important to ensure that both signals have the same number of processing stages. Setting up a compressor on the unprocessed signal with more modest settings than the parallel compressed signal can accomplish this, ensuring that both signals go through compression stages and are delayed the same amount of time.
Why and when do you use Parallel Compression?
When regular compression fails to produce the desired outcome, parallel compression may be utilized. The insufficiencies of conventional compression, such as disrupted transients, the loss of high-frequency components, or an excessive amount of unwanted noise, may be the cause. Additionally, the need for greater control over the dynamic range may be a factor.
However, the question of when to employ parallel compression remains. The answer, rooted in music production culture, is contingent upon various factors. First, the purpose of the (parallel) compression must be considered. Is it intended to manage the dynamic range, add color and character to a sound, or improve the cohesiveness of a group of sounds? This will not only determine which sounds should be subjected to parallel compression (thus answering the “when/in what situation?” inquiry), but also provide a general guideline for the appropriate settings. Typically, (parallel) compression is utilized on percussion, vocals, and in the mastering chain.
Parallel Compression on Drums (Drum Bus)
Using parallel compression on drums is a widely used technique among producers who desire to maintain the drums’ power and consistency throughout a mix. This is crucial because the strong beats of the drums provide the foundation for various forms of dance music. Moreover, drum sounds are susceptible to sharp volume peaks that need taming to increase a track’s overall volume and compete in the loudness war.
By utilizing parallel compression, you can manage the dynamic range of individual or grouped percussion sounds, ensuring their impact remains consistent across the track. Furthermore, as drum punch and transients are crucial, parallel compression provides enhanced control.
As we’re using parallel compression rather than regular downward compression, a low threshold and high ratio are used to create a heavily compressed input signal.
The attack setting determines how quickly the compressor responds after receiving a trigger, and a slow or long attack (around 30 ms) is recommended initially to avoid altering the initial punch of the drum sound.
The release setting dictates how long the compressor operates after the trigger signal ceases. To preserve the drums’ punch, a fast or short release is ideal, ensuring that it stops functioning right before the next drum sound triggers it.
Parallel Compression on Vocals (Vocal Bus)
Vocal recordings tend to have a wide dynamic range, which means there’s a significant volume difference between the loudest parts and the softest whispers. While parallel compression isn’t typically used to add character to vocals or blend multiple vocal sounds, it’s highly effective in highlighting the low-level details of a vocal recording. This technique can enhance the natural drops in volume, such as at the end of a phrase or when transitioning to a lower register, bringing the vocal to life.
Regarding the optimal settings, a medium attack time of about 4-6 ms and a very fast release are recommended.
Parallel Compression for Mastering
Parallel compression is also commonly employed in the mastering process. However, it’s essential to determine your desired outcome before making any adjustments to the master track or stereo output.
If your goal is to add punch and dynamics, it’s crucial to maintain the transients’ integrity. This can be achieved by employing the same settings as parallel compression on drums, such as an attack time of 10-30 ms for sharper or snappier transients, and 30-100 ms for punchier, heavier sounds like kick drums. The release setting could be approximately 100 ms, but it’s recommended to experiment with different settings to determine the best fit for your track. Trust your ears!
On the other hand, if you’re looking to increase the track’s density, you’ll need to use shorter attack and release times than the previous settings. However, it’s generally recommended to avoid going below 10 ms (attack) and 50 ms (release). If the sound is distorting, reduce the compression ratio slightly, even if the transients require more compression.
