Audio Limiting vs Clipping vs Maximizing: Understanding the Differences

In the world of audio mastering, there are a few techniques used to control the levels of audio signals.

These techniques: audio limiting, audio clipping, and audio maximization are often confused, but they are actually distinct processes that serve different purposes. In this article, we will explore the differences between these techniques and when they should be used.

Audio Limiting

Audio limiting is a process used to prevent audio signals from exceeding a certain level - typically the maximum level that the recording system can handle. Limiters are used to prevent audio signals from clipping, which can cause distortion and loss of quality. Limiters work by reducing the volume of the audio signal when it exceeds a certain threshold. This ensures that the audio signal remains within the maximum level, avoiding distortion and preserving the audio quality.

This is usually achieved using lookahead processing, which allows the limiter to 'look into the future' and preserve the signal.

The drawback of limiters is that they are extremely aggressive in their processing, and as such when feeding complex program material into them, they can alter the timbre and dynamic qualities of the material quite heavily in order to avoid audible distortion.

Audio Clipping

Audio clipping occurs when the audio signal exceeds the maximum amplitude that the recording system can handle. This results in a distortion of the audio signal that is often described as "clipping". Clipping is a result of the audio signal being truncated, or cut off, at the maximum level. 99% of the time this is an unwanted effect and should be avoided at all costs.

The other 1% of the time, it can be an effective tool to employ during the audio mastering process. Due to the severe nature of clipping, it can actually be used to artificially truncate a waveform's peaks, turning them into hard square waves. Because hard square waves cannot exist in the analogue domain, what this effectively does is program the reproducing digital-to-analogue converter to overshoot, and create faux peaks where the original peaks were truncated.

Why would we want this? Well, hypothetically for a given volume, a limiter may have heavily neutered the volume of drum transients in a song. Ever used a limiter and heard your snare completely disappear? We all have.

Clipping, conversely, will have truncated those drum transients, causing the digital-to-analogue converter to recreate them in the analogue domain. This means for a given volume level, clipping can actually retain more perceived dynamics in a master than limiting.

The drawback to clipping is that unless it is wielded with finesse, and used sparingly, it can cause audible distortion and degradation of the audio signal. Use with care.

Audio Maximization

Audio maximization is a catch-all term, referring to anything and everything that increases the audio volume to the ceiling of a system, whilst minimizing distortion. In practical terms, you can think of it as a clever combination of clipping and limiting.

An emergent modern approach, algorithmically-driven, maximization attempts to fuse the best parts of clipping and limiting together. The advantage here is that, ideally, you are able to combine the transient clarity and dynamic-preservation qualities of clipping, with the distortion-resistance of limiting, all while achieving extremely loud volumes.

An algorithm which does this for you in a crafty way is the Hybrid processor found in Flatline 2. This was tuned specifically to employ clipping where it operates best (on the transients) while using limiting where it operates best (on steady-state portions of the signal). This allows for immense volume, while retaining all the punch of the percussion.

When to Use Which Technique

It's important to use the right technique for the right situation. Limiting should be used in situations where the audio signal needs to be kept within a certain level to prevent clipping at all costs. Clipping should generally be avoided, unless intentionally being used for its dynamics-preservation qualities in mastering. And maximization should be used in situations where the audio signal needs to be made as loud as possible, while preserving audio quality.

Understanding the differences between audio clipping, audio limiting, and audio maximization is important in ensuring the best audio quality possible. Knowing when to use each technique and understanding the purpose of each process is key to producing high-quality audio recordings.

Which is Right For You?

Luckily, you don't have to make a decision right now. Tools such as Flatline 2 combine all 3 in the one user interface, allowing you to play with each sound, depending which is right for your music.

The Limiter is there for those who must avoid distortion at all costs. The Clipper is there for those who want that transparent, punchy sound of 90s and 2000s masters clipped through world-class converters, and for those who want it all rolled together: there is Hybrid.

Hybrid uses a proprietary blend of assorted maximization techniques to create extremely clean, punchy masters while being extremely distortion resistant. Some would call it the best of both worlds.