Clipping vs Limiting

Introduction

One of my Patreons asked me a great question today (thanks, Nick): What are the main differences between clipping and limiting?

There is a quick answer to this. And then there is more. It is a rather complex topic. So I decided to write a blog post in order to open up my perspectives a little bit more.

This is not a technical guide to clipping and distortion. I’m not qualified to write that, and I don’t think that would be very useful for the majority of the people reading this blog. This is just my attempt to boil the question of clipping vs limiting down into practical information. To share with you what I’m doing right now. If you have any further thoughts, feel free to drop your comments.

Clipping vs Limiting: The Quick Answer

Both clippers and limiters aim to stop (or sometimes reduce) peaks above threshold. But they use very different methods to achieve this goal. Clippers stop peaks by distorting them. By contrast, limiters try to do everything they can to avoid distortion. Both methods have advantages and disadvantages.

Clippers can retain the punch and integrity of the material better up to a certain point. Clipping can also be used creatively to enhance the impact and harmonic nature of the music. After a certain threshold (which varies greatly depending on the material and the clipper), clipping begins to sound nasty as a larger part of the material begins to get distorted.

Limiters are very good at getting more loudness out of the material without audibly distorting it. They apply many different methods to reduce and mask distortion. As a side effect, they can take away some punch and alter the spectral balance and stereo image of the material. Bass takes up a lot of energy, so it often gets traded for loudness.

In many styles of music today it’s common to combine clipping with limiting. This can give you the best of both worlds. Instead of limiting 5 dB, you could first clip 3 dB and then limit 2 dB. Or you could clip a little bit on the individual tracks or buses and just use a limiter on the master bus. Combining clipping with limiting can give you the same level of loudness with more perceived punch and transparency, as opposed to using a limiter alone.

That is my short answer on what are the differences between limiting and clipping. Now let’s look at some aspects of the topic in more detail.

Not All Clipping is the Same

Clipping is distortion. But not all clipping is the same. In the digital domain, it’s generally not a good idea to clip using a tool that is not designed to do that. It is better to use something that knows how to create the right kind distortion and how to deal with aliasing (a nasty side product of nonlinear processing).

Aliasing doesn’t happen in analog domain. That doesn’t mean clipping in analog will automatically sound good. But in that sense experimenting with it in analog domain is safer. Some mastering converters, for instance, are specifically designed so that you can clip them without adverse side effects.

Back to digital domain. Dedicated clipping plugins are designed to process audio and to clip in specific ways. They often apply techniques like oversampling to reduce undesired side effects such as aliasing.

There are big differences between different clipping plugins, too. Some aim to be transparent and some colour the sound in different ways. There are clippers that do hard clipping, others that do soft clipping and with some you can adjust the style.

Some clippers have low latency and CPU consumption, while others only care about maximising sound quality. There are single band and multi band clippers. There are plugins that combine clipping with saturation, compression or limiting.

Above all, each clipper plugin tends to sound different. It’s not apparent with small amounts of gain reduction, but the differences become very noticeable when pushing them harder.

As you can see, clippers are definitely not a unified bunch. Different tools for different situations. I always recommend to try different ones and see what works best for you.

A Few Words About Limiters

Limiters are essentially compressors with infinite ratio. Instead of distorting the peaks, they work by reducing the level of the peaks.

They also have some very clever tricks up their sleeves. For instance, they may apply a lookahead in order to predict the peaks. This introduces latency, but allows the limiter to react to peaks in more transparent way.

Limiters try to minimise audible distortion by preventing it as much as possible. And when distortion inevitably does occur, limiters attempt to mask it by using psychoacoustic models and other methods. Some limiters apply different processes to different parts of the signal under the hood. They can be quite complex beasts and like clippers, each one is different.

All this processing never comes without side effects. Depending on the material, the limiter in question and how hard you are hitting it, you may lose some punch or alter the spectral balance or the stereo image of the material.

Because I do mastering, I have different limiters in my toolbox for different occasions. Most people should be just fine with one good limiter (indeed even I stick with just one most of the time).

How I Use Clipping

I use clipping for different purposes. Don’t get me wrong though. I don’t always use clipping to achieve these things. I may also use limiting, compression, saturation or any combination of them and/or clipping. Never the less, here are my common use cases for clipping:

1. To transparently control the dynamic range on individual tracks or buses. Usually to shave off excessive peaks in order to help the dynamics processing further down the line. For this purpose I either clip in analog (Prism Sound Titan AD converter) or I use the SIR StandardCLIP plugin. StandardCLIP has good metering and nicely adjustable oversampling and other controls which makes it suitable to use on individual tracks.
2. To achieve harmonic effects. For example, clipping a snare drum or a drum break to give it some edge. For this I tend to clip in analog by driving my mixer (Midas Venice 320) hot and then finishing the clip with the AD converter. ITB, one could use a clipping plugin that can produce some nice character, like Kazrog KClip.
3. To achieve some loudness by clipping the master before final limiting. I often first clip the AD converter just slightly. I will then follow that with the Voxengo OVC-128 clipper. It first gives you some transparent gain but then begins to add some character which I really happen to like on my own music.

My Fav Plugins

If you want a more detailed lowdown on the tools I’m using, check out the new “Tools I Love” page. But here’s a quick list of what I’m currently using for clipping and limiting.

Clipping Plugins

These are currently the best clipping plugins for me.

• Voxengo OVC-128 for the master on my own tracks. Sounds great and the processing is of great quality. I like the character it introduces for my music.
• SIR StandardCLIP for individual tracks/buses or transparent mastering tasks. Good metering and very adjustable for different situations. Can also get pretty grungy if you like.
• Kazrog Kclip for character on individual tracks/buses.

Limiter Plugins

These are currently the best limiter plugins for me.

• DMG Audio Limitless is my main limiter. It also includes a great clipper. It’s a very deep plugin and requires some dedication to get the best out of it. Even after a year I am still learning.
• iZotope Ozone Maximiser is a great fit for most people. Sounds great even when pushed and not difficult to set up.
• Voxengo Elephant is a transparent and open limiter that also goes pretty loud. Lots of options if you want to tweak. If you are going for a big and open sound, try this.
• Eventide Elevate for punchy loudness. The tradeoff is it can change the character of the material. Also includes a clipper and a multiband transient section.
• Because you are probably thinking about why it isn’t mentioned, let’s talk about FabFilter Pro-L2. I have used it a lot in the past. It’s a good plugin. But the competition is fierce. For what I’m doing, I more often than not get better results with one of the other limiters I’ve mentioned. The differences are probably insignificant for most people. But in mastering work every little bit matters. Then again, I’m sure there are mastering engineers who prefer the Pro-L2. So just do your own testing before making any buying decisions.

Conclusion

Clipping and limiting can be useful, but very destructive tools – especially on the master bus. Be very careful with them. It’s easy to set something up and then accidentally drive it too hot later on. Keep a close eye on the metering so that you always know how hard you are hitting something.

If someone else is doing the mastering, it’s best to leave final clipping/limiting to them. They can likely try different tools to find what works best with the material. Above all, they have the ears, experience and the playback system to evaluate it neutrally.

This shouldn’t stop you from experimenting and learning though. It’s worth exploring how different clipper and limiter plugins react with your material and how you may want to use them.