If you are reading this you probably want to know how you need to set up your Limiter to get the best result. To make it clear: There is not the one setting that fits all. However if you understand WHY to use a Limiter in the first place and HOW it works, you will naturally come up with settings that will fit your music! So let's dive in!
TLDR;
Here are the key takeaways from this article:
- Limiting prevents audio from exceeding a set volume threshold and therefore distortion
- Limiting is used to increase the perceived loudness in order to make your track sound better
- Try to reach roughly the same LUFS that is common in your music genre
- Start with long Attack and Release values
- Use gain matching in order to judge the changes in dynamic range better
- Listen to the Delta Output to recognize artifacts faster
- Optimize for a balance between dynamic range and loudness
What is a Limiter and How Does it Work?
At its core a limiter does nothing more than preventing your Audio to go over a certain threshold (-15.86 dB like in the graphic f.e.). Sounds simple right?
Why do I need a threshold?
Well, because your device has one. Unfortunately every listening device has a maximum of loudness it can output. If the waveform of your audio would exceed that maximum you'd probably get some nasty distortion artifacts. The solution to this is to determine a digital ceiling for the output which cannot be exceeded. In the simplest form you could just clip your audio at 0 dbfs, which determines the said ceiling. However this would usually result in said distortion artifacts which you probably don't want. So then...
What does a Limiter do?
A limiter is a specialized compressor that prevents your signal from going over the said threshold as smoothly as possible. Imagine yourself drawing a volume automation in your DAW in order to prevent clipping. Thats essentially what a limiter does for you... only in an extremely precise and hopefully unnoticeable or even beneficial way. Of course it does not do this entirely by itself, since you probably want to adjust its behaviour in order to get the most out of the process. We'll go over this in the next few paragraphs!
Why turn it up anyways?
If surpassing the 0 db threshold is so bad, then why not avoid clipping by reducing the overall volume level right?
In the "early days" of digital audio this has actually been the case! Sound engineers would just turn your audio down to a level where no peak was crossing the 0 dB limit. However studies have shown that people would prefer a louder piece of music over a quieter one. This lead to the demand of louder and louder masters, ultimately becoming the commonly known "loudness war". Nowadays Limiters are working with pseudoacoustic tricks to achieve exactly that: A master that is as loud as possible with the least amount of audible distortion possible.
Can it be too loud?
Yes. There are several reasons why pushing your track up too much can be harmful. Firstly, (and this is what plugin developers will rarely tell you) at some point even the best limiter in the world won't be able to increase the volume without some form of distortion. This of course reduces the quality of the audio.
Secondly, constantly pushing the volume to its limit can lead to listener fatigue and discomfort. It can also cause long-term damage to hearing.
Furthermore, the excessive changes in amplitude can mask nuances and dynamics in the music, making it less enjoyable to listen to and diminishing the overall quality of the sound. More commonly said: The track looses its' "punch".
Instead of aiming for maximum loudness, it is important to focus on achieving a balanced and dynamic mix that preserves the integrity of the music. This became especially important when streaming services added automatic gain compensation to their services.
The perfect level
To understand what you should aim for it is important to understand one metric that has become very important over the recent years: LUFS
LUFS stands for "Loudness Units Full Scale" and it is a measurement of the perceived loudness of audio. It is used to ensure consistent loudness levels across different audio sources, such as songs on a streaming platform or commercials on television.
Streaming platforms will usually adjust the level of your track to -14.0 to -10.0 LUFS (see the info graphic). 
This level allows for a balanced and dynamic mix that doesn't need to be heavily compressed or limited, preserving the details of the music. So should you then just turn up your track until it hits the -14.0 LUFS mark?
While many inexperienced mastering engineers think that way, there are more factors to take into account. The most important one is your genre. If you download an LUFS meter and measure your favourite tracks you will probably read values that are way higher than -14.0 LUFS. The reason for that is context. Limiting the audio to the max has become so common that it almost belongs to some genres. People are so used to that kind of sound that a track that breaks the with that norm could stand out negatively. For example if you would play a -14.0 LUFS EDM track in a set where the norm is -6.0 LUFS the crowd would probably be very confused. 
So the best thing to do would be analyzing the loudness of similar tracks and keep up with them. But bear in mind that nowadays you don't have to be the loudest anymore. Aim for the highest possible uncompromised sound. How that is done is described in the next lines.
Setting Up a Limiter for Audio Mastering
Adjusting the threshold for optimal results
One of the fundamental aspects of using a limiter is setting the threshold. This parameter determines the point at which the limiter begins to affect the audio signal. Essentially the Threshold is the barrier that your audio cannot surpass. By carefully adjusting the threshold, you can ensure that your track maintains a sufficient level of loudness without compromising its overall clarity and dynamics.
Attack and Release
Most Limiters will offer you an Attack and a Release knob. The Attack time describes how fast the limiter pushes the waveform of your audio down if it crosses the threshold. Release on the other hand describes how fast the limiter brings your audio back up after it has been ducked down. It's important to notice that every limiter does this quite different internally (that's why there are so many of them). So the best thing to do would be experimenting. to give you a headstart here are some basic insights:
Longer Attack times often sound more natural with the downside of more distortion.
Shorter Attack times often sound jumpy or pumping when especially combined with short to medium Release times.
Very Long Release times can sound very natural but they prevent the audio from getting louder.
Short Release times allow the audio to becom louder with the risk of sounding unsteady.
Punch
The Zykon Limiter also offers a "Punch" knob. As stated earlier one of the main downsides of using a Limiter is loosing the punch of the transients in your track. With this knob you can bring the punch back up which makes your track sound extremely clean and dynamic even at very high compression rates.
Lookahead
Some limiters offer a Lookahead value. This is a feature that allows the limiter to anticipate the incoming signal and prevent any potential clipping or distortion before it occurs. By "looking ahead" at the incoming audio, the limiter can react in advance to any peaks or transients, adjusting the gain to ensure that the output remains within the desired limits. The Zykon Limiter sets this value dynamically by itself, so you don't need to worry about it ;)
Using true peak limiting for digital releases
With the prevalence of digital streaming platforms such as Spotify and Apple Music, employing true peak limiting has become essential. True peak limiters account for intersample peaks, guaranteeing that the audio remains within the acceptable limits when converted to digital formats, thereby preventing any potential distortion or sound degradation upon playback. 99% of the time you don't really need to worry about this - Just turn on the true peak mode of your limiter and you should be fine.
Output Gain
We recomend to set your Output Gain to -1dB. This has mainly two reasons: Firstly you'll prevent clipping when converting your track to MP3 for example. A lot of compression formats can cause slight gain changes. Therefore it's best to give the audio a little more headroom.
Secondly some streaming services demand your master to be at -1dB true peak level. Otherwise they will turn your track down in volume.
Oh and please make sure the limiter is always the last plugin in your mastering chain ;)
Common Issues and Solutions When Using a Limiter
Dealing with clipping and distortion
As said earlier, one of the primary challenges when using a limiter is the potential for clipping and distortion, particularly if the input gain is set too high. To mitigate these issues, mastering engineers need to exercise caution when adjusting the input gain and threshold to prevent any unwanted artifacts and ensure a clean, distortion-free sound. However here are two tips to make it easier for you:
1. Listen to the "Delta Output". The Delta Output is the signal that is being taken away from your audio in order to squash it under the threshold. It usually gives you a good impression of how the introduced artifacts sound like. If you can recognize your track in the delta signal you are probably compressing your signal too much.
2. Overcompress your track really hard, so that you can get familiar with the artifacts the limiter produces. Try to find the the setting with the lowest audible artifacts. Oftentimes this is the best setting that you can choose! After that reduce the Loudness until you can't hear any artifacts anymore.
Dynamic range and Pumping
Dynamic range refers to the difference between the loudest and softest parts of a piece of audio. It is important in music production as it adds depth, interest, and emotion to a track. However, excessive dynamic range can make it difficult to hear certain instruments or vocals, especially on devices with limited playback capabilities.
Pumping, on the other hand, is an unwanted effect that occurs when the volume of a track or certain instrument abruptly jumps up and down. It can sound unnatural, distracting, and disrupt the overall balance of the mix.
Pumping often happens when compression or limiting is applied in an excessive manner with the wrong attack and release values.
To avoid pumping, it is essential to approach limiting with caution. It is advisable to start with long attack and long release values and make incremental adjustments until the desired effect is achieved.
One helpful technique to assess the impact of dynamics processing on a track is gain matching. By temporarily adjusting the volume level to match the original signal before and after compression, you can better hear the changes in dynamics. This ensures that the limiting is enhancing the track without causing pumping or any unwanted artifacts.
Limiters vs Compressors: When to Use Each
Key differences between limiters and compressors
While compressors and limiters share similarities, it's essential to grasp the distinction between the two. Unlike compressors that subtly shape the entire dynamic range of a sound, limiters serve the specific purpose of capping the maximum level of a signal. They are employed during the mastering process to achieve a consistent and balanced volume throughout the track. In short: Compressors are ideal for taming dynamic inconsistencies and adding coloration to the sound, whereas limiters excel in controlling peak levels and enhancing loudness without significantly altering the overall tone.
Utilizing compressors in conjunction with limiters
Integrating compressors and limiters within the mastering workflow can yield remarkable results. By strategically applying compression to address dynamic nuances and subsequently employing a limiter to ensure consistent loudness and peak control, mastering engineers can achieve a balanced and professional sound that is optimized for various playback systems.
Applying threshold, ratio, and release time in compression and limiting
Understanding the interplay between threshold, ratio, and release time is crucial when utilizing both compressors and limiters. By fine-tuning these parameters, producers can effectively tailor the dynamics and loudness, achieving the desired balance between preserving the natural dynamics of the music and enhancing its overall impact.