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.
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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.
How to Apply Upward and Downward Compression
The process of applying upward and downward compression is straightforward, but it requires careful consideration of several factors. The first step is to determine the type of compression that is needed. This is determined by the nature of the audio material and the desired outcome of the mix.
Once the type of compression is determined, the next step is to set the parameters of the compressor. This includes setting the threshold, ratio, attack time, and release time. Threshold determines the level at which compression starts, ratio determines the amount of compression applied, attack time determines the time it takes for compression to start, and release time determines the time it takes for compression to end.
The key to successful compression is to use it sparingly and with a gentle touch. Over-compression can result in a lifeless, flat mix with no dynamic range. On the other hand, too little compression can result in a mix that is too dynamic and lacks consistency.
Benefits of Upward and Downward Compression
The benefits of using upward and downward compression in audio mixing and mastering are numerous. Some of the most significant benefits include:
Improved Clarity: Upward compression can enhance the clarity of the quieter elements in a mix, making them more audible and stand out in the mix.
Dynamic Range Control: Downward compression reduces the dynamic range, making the mix more cohesive and preventing the mix from becoming too loud or clipped.
Consistent Loudness: By reducing the dynamic range, the mix becomes more consistent in loudness, making it easier to listen to for extended periods.
Improved Tonality: Compression can shape the tonality of the mix, making it sound more polished and professional.
Frequently Asked Questions
What is compression in audio mixing and mastering?
Compression is a process in audio mixing and mastering that adjusts the volume of the audio by reducing the dynamic range. It allows audio engineers to control the volume of the audio and shape its tonality.
What is upward compression?
Upward compression is a type of compression that increases the volume of quieter elements in the mix while keeping louder elements in check. This technique is used to enhance the perceived loudness and clarity of the mix.
What is downward compression?
Downward compression is a type of compression that reduces the volume of the loudest elements in the mix. This technique is used to prevent the mix from becoming too loud or clipped and to maintain a consistent loudness level.
What are the different types of compressors?
There are several types of compressors that are commonly used in audio mixing and mastering. These include opto-compressors, FET compressors, VCA compressors, tube compressors, and digital compressors.
When should I use upward compression?
Upward compression should be used when you want to enhance the presence of quieter elements in the mix. This technique is commonly used to improve the clarity of spoken word recordings, bring out the details in delicate instrumental solos, and enhance the presence of background vocals and acoustic guitars.
When should I use downward compression?
Downward compression should be used when you want to reduce the volume of the loudest elements in the mix. This technique is commonly used to reduce the dynamic range of lead vocals and drums, prevent the mix from becoming too loud or clipped, and maintain a consistent loudness level.
What are common compression techniques?
Common compression techniques include multi-band compression, parallel compression, and sidechain compression. These techniques are used to achieve specific goals in audio mixing and mastering and allow audio engineers to control the dynamic range and shape the tonality of the mix.