We are aware that although they typically lower the level of the input signal when it exceeds the threshold, compressors can make things appear louder or softer. But there are other methods of compression as well. We can increase the signal below the threshold rather than suppressing things when they rise above it.
Upwards Vs Downwards Compression – What’s The Difference?
We are aware that when it comes to compression, the threshold setting is crucial in determining the overall nature of the result. The signal’s treatment whether it is either below or above the threshold is the key distinction between upwards compression and downwards compression.
While upward compression only handles the signal when it is below the threshold – by enhancing it – downward compression only impacts the signal after its level above the threshold. Although upwards compression appears to be a whole different strategy to those who are only familiar with downwards compression, it really compresses the signal just as effectively.
So, with upward compression, the dynamic range is reduced similarly to downward compression, but the soft parts grow louder rather than the loud parts being softer. But in the end, these two effects sound different and have various applications, advantages, and disadvantages.
Although upward compression and downward compression are two different variations of the same effect, they are two entirely distinct creatures that are best suited for various applications.
Only when the signal exceeds the threshold is it subjected to downward compression, which lowers the volume or “pushes” the signal. However, upward compression only impacts audio signals that are below the threshold because it amplifies and pushes everything upward. The signal is compressed, and the dynamic range is decreased, which has a similar overall impact. But the way the compressor actually handles the signal differs, leading to two unique effects.
Of course, there may not be a choice between the two. You can employ upwards compression and downwards compression combined to offer you even more control over dynamics, much to how your effect chain might use several compressors performing varying levels of gain reduction.
What is Downward Compression?
Downward compression evens out the overall level of a signal by bringing the louder portions closer in volume to the softer portions by “clamping down” on anything above the threshold. The “de facto” type of compression is downward compression. 90% of hardware and software plugins marketed as limiters or compressors employ downward compression.
Once the signal crosses the threshold, the ratio determines how much compression to apply downward. We used an x:1 option to set our ratio. In order for the output sound to be 1 dB above the threshold, the input sound must be x dB above the threshold.
We will notice a 3 dB reduction in volume, for instance, if we use a 4:1 compression ratio and our signal crosses the threshold by 4 dB. With the identical parameters, a signal would lose 6 dB if it exceeded the threshold by 8 dB.
What is Upward Compression?
While maintaining or largely preserving everything above the threshold, upward compression increases the amplitude of anything in the audio signal below it (according to the knee). This can be helpful in situations where you can clearly hear the louder portions of a recording but struggle to distinguish the softer portions.
For instance, there may be spots in a live recording of a band when the enthusiasm wanes a little too much, but for the most part, the volume is fine. If you employ downward compression to level out this track, the compressor is always on. With upward compression, however, the compressor only engages when it is truly necessary.
In my perspective, the best thing about upward compression is how it highlights some undertones that would otherwise go missed. When pushing elements into the foreground, upward compression is a fantastic textural enhancer. We’ll discuss some practical examples shortly. Not many plugins are specifically identified as upwards compressors. Instead, upwards compression is more likely to be found as a mode in a compressor plugin or hidden away as a secret component of a “one-knob” improvement plugin.
You enter OTT territory when you discuss multiband upwards compression. Three or more distinct frequency bands are forcibly leveled out by OTT, a sort of multiband compression effect (eg. bass, mids, highs). The outcome is far cleaner than distortion, with each band essentially compressed into a solid tube of sound.
Both downwards and upwards compression are used in OTT compression to accomplish this, although it’s safe to conclude that upwards compression is the essential component.