Transcript
In this tutorial, I’m going to explain what a limiter is, its basic controls, and discuss three common applications in which I’ve used a limiter in my tracks. So, let’s get started.
My name is Daniel and I am the founder of SoundShock. Before we get started, I want to let you know that I release tutorials on the SoundShock YouTube channel every other week. These tutorials cover on all things electronic music production related, such as mixing, mastering, sound design, and arrangement. So be sure to click the subscribe button on my
Website so you don’t miss out when I release a new video
Before you read this tutorial, I want you to know that I cover all of this information in my YouTube Video on How to Use a Limiter. Also, I think you would find it very helpful to I want to watch YouTube tutorial on how to use a compressor before getting into this tutorial or my video on using a limiter. In this earlier tutorial I go over the basics about dynamics, compressors and the basic compressor controls. It is essential to know about compressors in order to understand how a limiter functions. So, if you don’t have a solid understanding of dynamics and what a compressor is, then watch my YouTube tutorial on How to Use a Compressor before you come back to this tutorial.
What is a Limiter? Comparing Limiters vs. Compressors
Now, a lot of producers may know about limiters and may have even used them in their tracks but may still be unclear on how they function. Many producers are looking for a comparison of limiters vs. compressors and that explains how they are different. So I’ll begin by answering the question: ”What is a limiter?” A limiter is a type of compressor designed for a specific purpose, that is to limit the level of a signal to a certain threshold. It is different from a compressor, because a compressor gradually reduces the signal level above a certain threshold, however a limiter completely prevents a signal from going over a specified setting. The limiter sets a maximum limit that nothing can exceed. Thus, a limiter is like a compressor set to a very high compression ratio.
Remember that the compression ratio is the strength of the compressor. A limiter will have a ratio of at least 10 to 1 and most commonly the ratio will be at infinity to 1 meaning the entire signal above the threshold is attenuated. If you look at a graph of compression ratios, you will see that with a 1 to 1 ratio nothing is happens. There is no compression or limiting applied and the output level is the same as the input level. If the compression ratio is increased to 2 to 1 the signal above the threshold is getting attenuated by a small amount and the output level is slightly lower. Using a stronger ratio a 4 to 1 gives an even lower output level and using a ratio of 8 to 1, which is a very strong ratio, the output level is significantly lower. Comparing this to a limiter which has an infinity to 1 ratio, you can see that once the threshold is reached, the output level remains the same because it is being limited.
The Basic Parameters (Controls) for a Limiter
Now I’ll go over the basic parameters of a limiter. Of course some limiters may have more parameters than the ones I discuss here, but I just want to go over the main ones. That will make it easier for you to start applying all the information right after reading this tutorial or watching my video. Limiters have three main controls, the first one is the threshold. Just like the threshold on a compressor which is used to set the level at which the signal is compressed, the threshold on a limiter sets the level at which the signal is limited. How much the signal gets turned down, depends on how far the signal is above the threshold. Be sure to check the attenuation or gain reduction meter, which shows you how many decibels the limiter is limiting. Whenever you reduce the threshold, the limiter is working harder to ensure that no audio is getting past the threshold.
The next parameter is the ceiling which is used to set the maximum output level. The ceiling ensures that you set the total output of your audio at the level you want it to be and to keeps it from clipping.
The last parameter is the release. The release of a limiter also functions similarly to that of a compressor. The release determines how quickly or slowly the attenuation of the limiting is restored to zero or no limiting. The human ear naturally responds to changes in sound. The faster the change, the more we like it, or the more we are aware of it. So, if you have a faster release time on the signal, it tends to make the audio sound louder. However, using a slower release times makes it sound quieter and duller. That means you usually want a fast release for very short but loud transients, because this will avoid uneven dips in volume and retain the loudness. On the other hand you usually want to use a slow release for moderate peaks in your audio, so a more gentle level control is applied. Limiters don’t usually have an attack control, because they are dealing with high amplitude transients and letting any of the original signal through would defeat the purpose. Limiters are usually set internally with a very short attack time or no attack time at all.
Common Situations for Using a Limiter
Now that we know the basic functions of a limiter, let’s go over three common situations in which limiting is useful.
THE FIRST COMMON SITUATION USES A LIMITER SIMILAR TO A BRICKWALL LIMITER
Often, when you do heavy processing on individual sounds, groups of sounds, or even your master chain, the audio can produce erratic dynamics and create very sharp transients with a very high in amplitude. These erratic dynamics could harm your audio system and your ears. They also create digital distortion and a clipping, which is the last thing that you want. What I like to do when this happens is to add a limiter like a “brickwall limiter” to the end of my master chain. This limiter is the last thing on the mastering chain and it is different from a mastering limiter because this limiter will only catch the erratic peaks which occur when we are processing our sounds.
Now for the settings of this brickwall limiter. In the examples in my video, I used the wavesl1 limiter. I chose this limiter because it has a nice graphical display and which makes it easy to see what is happening. But any limiter can be used, because most limiters have the same three basic controls: the threshold, output, ceiling, and release. In the first example on my video I set the limiter the threshold at 0 decibels and I also set the output ceiling at 0. As I discussed above, we want to reduce the audio when a high dynamic peak comes in so we can avoid clipping and digital distortion. That’s why we want the threshold and output ceiling to be at the lowest settings. These settings insure that the limiter won’t be working at any other time. For the release, I set it for its fastest time. because fast release times are necessary for high transient material. If I used a slower release, when the high transient material passed, the limiter would be slow to return to 0 decibels. This would cause a noticeable volume difference.
So, to review, you should put a brickwall limiter on your master chain the entire time when you are working on your song. I usually like to put this on at the very first thing before I even start my track. Another good time to use a brickwall or safety net limiter is when you are recording. Whether you are recording a guitar, drums, or a vocal, throwing this limiter at the end of your recording chain will help keep your audio from going into digital distortion and clipping. In the video I use the example of recording when the vocal singer is a little too close to the microphone. When this happens, the volume is much greater and it is clipping. However by putting a limiter on the end of the audio chain before recording, the clipping would be avoided because attenuation would begin when the louder part of the vocal comes in. That is why this is called an audio safety net.
THE SECOND COMMON SITUATION USES A LIMITER TO SCULPT THE SOUND.
Often, when you have high transient audio, which may be leads, drums, or anything else that has a sharp attack. These sounds eat up headroom in the mix, especially if you are layering high transient material together, such as drums. The peaks of these, transients will come together and create a very high amplitude transient which throws off the dynamics of your song. Since the rest of the elements in your track are quieter, when this high transit material comes in there is a very sharp peak. In the video. I play a drum sample with a very high peak that is eating up a lot of headroom in the mix unnecessarily. I then use the limiter to sculpt this sound so the peaks are a bit more tame. Of course, instead of using a limiter, you could have turned down the volume of the percussion, but this would still leave the very high transient attack. That is why it is better to sculpt the transients of this attack to have the dynamics fit in better.
In the video example I show how to adjust the limiter’s controls to sculpt the sound. First, I adjust the threshold to cut out the peaks by listening to the audio while setting the control. I leave the output ceiling we at 0 decibels. Then I set the release is at its fastest time. As I discussed above, this is the best setting when you are dealing with short high transient material because you want the limiter to recover as quickly as possible. This results in a lot of gain reduction on the audio which is how we want to sculpt the sound by reducing the short high transients In the video compare at the waveforms percussion with and without the limiter on. This demonstration shows that the limiter has cut off the high transient material resulting in a lot less of a peak after limiting. Try this comparison yourself, then, listen to the percussion with and without the limiter and you will be able to hear the difference. The unlimited percussion will have a very sharp biting attack and the limited percussion will be more balanced. The short high transients in the unlimited percussion create an imbalance and eat up Headroom in your mix. That is why you should use a limiter to tame peaks like that.
THE THIRD COMMON SITUATION USES A MASTERING LIMITER
Often, when you have high transient audio, which may be leads, drums, or anything else that has a sharp attack. These sounds eat up headroom in the mix, especially if you are layering high transient material together, such as drums. The peaks of these, transients will come together and create a very high amplitude transient which throws off the dynamics of your song. Since the rest of the elements in your track are quieter, when this high transit material comes in there is a very sharp peak. In the video. I play a drum sample with a very high peak that is eating up a lot of headroom in the mix unnecessarily. I then use the limiter to sculpt this sound so the peaks are a bit more tame. Of course, instead of using a limiter, you could have turned down the volume of the percussion, but this would still leave the very high transient attack. That is why it is better to sculpt the transients of this attack to have the dynamics fit in better.
Using a limiter at the very end of your mastering chain is called a brickwall limiter. The mastering limiter is used to increase the perceived volume of your entire track so it can stand up to the volume of all the other commercial tracks. This goal is a lot different from the goal in situation one where the limiter was used to provide an audio safety net. When using a mastering limiter, your goal is to bring up the volume of your final track. The effect of using a mastering limiter is to bring up the volume of the quieter audio in your track and reduce the volume of the louder peaks. To achieve this effect, you should adjust the threshold control while you are listening to the track. For example you might decide to move your output ceiling down to around -3 decibels. You shouldn’t set your ceiling to 0 decibels because you want to leave enough room for intrasample peaking. Without getting too technical here and depending on which system you play your song on, if you have a ceiling of 0 decibels, there could be distortion. To avoid this, I tolerate a little bit of a ceiling here to make sure that my track is not distorted and doesn’t go into digital clipping on any system that it is played on. Some might say that -3 decibels should be your desired ceiling. However, today’s tracks are very loud, so having the highest possible ceiling before it distorts is ideal.
After you adjust the threshold, adjust the release time. You will probably keep it around three milliseconds. Listen to the track and adjust both the threshold and release time.. You want to find the sweet spot where the limiter sounds transparent and there is no noticeable dip in volume in the transients.
Because today’s tracks are very loud, limiters are pushed quite hard, especially with electronic music. To achieve this sound, pull down the threshold until you start hearing distortion and then pull it back until you don’t hear any more distortion. That usually indicates where you will place the threshold on your master chain limiter
That explains how to use a mastering limiter to boost perceived loudness of your track and make it able to compete with the loudness of other commercial recordings.
To explain this better, refer back to situation two where I used a limiter to sculpt my sounds. If there was a very high amplitude transient percussion in the track and I didn’t sculpt those sounds like I did in the second example, then the limiter would cause distortion quicker when I turn down the threshold. That happens because the high peaks would cause the mastering limiter to trigger when the rest of the audio is not at this high amplitude. That would cause the mastering limiter to work harder and distort faster. The result would be to keep you from being able to turn up the perceived loudness of your tracks. If that occurs, you will be unable to get you tracks as loud as other commercial tracks. In addition, keeping your dynamics in check is important for the overall mix and master of your song.
In this tutorial I have covered three common situations in which I use a limiter. Of course, these are not the only situations in which a limiter is useful, but they are the most common situations which means they are the best ones for you to apply to your tracks right now.
