- Confused between upward vs downward compression?
- We drill down the differences in a beginner-friendly way.
- Learn sound design techniques involving upward and downward compression!
Upwards Vs. Downwards Compression: Differences
Upward and downward compression are two types of audio compression that operate in opposite directions, and they differ in how they treat the signal when it is either below or above the threshold.
Important! The threshold setting is a crucial parameter in both upward and downward compression, as it determines the level at which the compression starts to take effect.
If you need a refresher on the terminology, check out our post on the basics of compressors.
| Downward Compression | Upward Compression | |
| Operation | Reduces the level of the loudest parts of a signal | Increases the level of quieter parts of a signal |
| Effect | Controls peaks and prevents distortion | Increases the perceived loudness of a signal without introducing distortion |
| Example Usage | Used on drums to control cymbal volume dynamics | Used on vocals to bring out quieter phrases/syllables. |
Downward Compression
Downward compression is the most commonly used form of compression. Most plugins and hardware units labeled as compressors or limiters use downward compression.
Downward compression reduces the level of the loudest parts of an audio signal.
Here’s a quick summary of downward compression:
- It applies gain reduction to the signal when it exceeds a certain threshold level.
- Any part of the signal that is louder than the threshold will be reduced in volume, resulting in a more consistent overall volume level.
When To Use Downward Compression
Use-Case #1: Controlling Peaks
Downward compression is used to control peaks and prevent distortion. This is useful for taming highly dynamic performances, which can, in turn, help you to achieve an overall louder mix.
This can be very useful on groups of instruments, such as drums (controlling cymbal volume). However, you can also use it to control the dynamics of single instruments, such as a bass guitar.
Use-Case #2: Tone-Shaping/Transient Control
With the appropriate attack, release, threshold, and ratio settings, you can use downward compression to shape the transient of a signal.
For instance, if you want to bring out the ‘crack’ of a snare drum and have it sit more forward in a mix, set the attack to fast, and the release to medium.
Upward Compression
Upward compression, on the other hand, is used to increase the level of the quieter parts of an audio signal.
Here’s a quick summary of upward compression:
- Works by applying gain to the signal when it falls below a certain threshold level.
- Any part of the signal that is quieter than the threshold will be increased in volume, resulting in a more consistent overall volume level.
When To Use Upward Compression
Use-Case #1: Fixing Imbalances In Live Recordings
Upward compression is useful in applications where you can hear the louder parts of a recording, but the softer sections are getting lost in the mix.
With downwards compression, the compressor is constantly engaged to bring peaks down. However, with upwards compression, the compressor only kicks in when the volume drops too low.
Use-Case #2: Adding Detail & Textural Interest
Try applying aggressive upward compression to a field recording. Listen as it helps you uncover all sorts of weird artifacts and hidden details.
I suggest using multiband upward compression like OTT for this, because field recordings have a wide frequency range.
Upwards compression is a great textural enhancer as it can bring out nuances that would have otherwise been buried (like the breathiness of a hushed, vocal take).
Use-Case #3: Otherworldy Reverbs
I’m also a big fan of using upward compression after reverb, as it greatly exaggerates the decay time to create “larger than life” reverberation effects. This trick works well on lead synths, vocals, or anything that you want to stand out in a track.
FAQ
Is OTT A Type Of Upward Compression?
Yes, OTT (Over The Top) is a type of upward compression. It is a specific type of multiband upward compression that is often used in electronic dance music (EDM) production to create a more powerful and impactful sound that is full of detail and color.
Before you Go…
We highly suggest checking out the linked resources throughout the guide, to help you further your knowledge on all the facets of compression.
We also have a 45-page handbook that covers all the ins and outs of compression.
