- Understand what audio clipping is
- Learn what causes clipping (and how to avoid it)
- Find out the difference between clipping, limiting, and compressing
Audio clipping is a term you’ve probably heard (and more so you’ve probably been told that clipping is a bad thing!).
In fundamental terms, clipping occurs when a signal (in this case, in a DAW) is loud enough to go past the maximum limit that the software can handle. Once this happens, a form of distortion occurs.
To help you understand how it occurs and how to avoid it, this article deep dives into audio clipping.
The Basics Of Audio Clipping
Clipping, in fundamental terms, happens when a digital signal becomes too loud for a digital system to handle.
When talking about systems such as Logic,
Decibels can be tricky to understand, so we’ll return to that later. For now, all you need to know is that 0dBFS is the point where our system cannot handle any more loudness in its signal.
If you’re familiar with compression, you’ll understand how the threshold parameter works. In the case of a compressor, some signal will be allowed past the threshold before being turned down.
This can ensure a smoother mix (or even be applied creatively).
However, in the case of our DAW, 0dBFS is essentially a threshold. If your signal is louder than this, you’ll encounter distortion that isn’t pleasant to listen to.
What Is dBFS?
dBFS is the digital scale that is used across modern digital audio software.
You may be a little confused as to why we monitor our mixes with minus numbers (eg -12dBFS), after all, 0 decibels would be silence, so surely minus decibels are, well, more silent than silence!
It can be tricky to navigate, but there is a difference between decibels (dB) and decibels full scale (dBFS).
Decibels are used to monitor sound pressure or the volume of a sound in the real world. So, in this case, a concert will land much higher on the scale of decibels than a library.
However, dBFS purely relates to a digital signal. Think of it this way, if you’re mixing a concert with digital equipment, your level may be -6dBFS digitally, but to the listener, the sound system could be playing at 100dB.
The two are completely separate, but nonetheless do have a link!
There, of course, aren’t any limits on dB (although, fun fact, supposedly 1,100dB could create a black hole if it were possible to produce a sound that loud!), while dBFs will always have a limit of 0.
The Importance Of Headroom
Headroom refers to the gap in your signal between the highest (or loudest) point and 0dBFS. For example, if your track is playing in your DAW at -6dbFS, then you know you have 6dBFS of headroom.
Whilst the general consensus is that a louder-sounding mix is more impactful than a quiet one (especially in genres like rock and metal), that doesn’t necessarily mean that cranking your track to its maximum will sound better.
Leaving some headroom on the track you are mixing is good practice for several reasons.
One is that if you are sending your music to a mastering engineer, they will need some room for plugins, EQ, and any other processing they may do.
Anything they add to the song (even if it’s boosting an EQ) will add a certain amount of gain, which increases the level and therefore leaves less headroom.
Another reason to leave headroom is for your own plugins. If you’ve maxed out a signal, and you decide to come back and add some saturation, modulation, or any other effect, then that is going to boost your level to some extent.
If the signal is really hot, then you’re risking clipping. Also, keep in mind that a lot of plugins automatically add a dB or two of gain when you insert them onto your track.
Is Clipping The Same As Distortion?
In fundamental terms, yes. Clipping is the same as distortion. But in many ways, it isn’t a fair comparison.
Yes, clipping a signal will cause distortion but not in the way you would expect to hear from a specifically designed distortion plugin or pedal.
These practical uses have been created to be pleasant to the listener, whereas audio clipping is the sound of an overloaded system.
That said, both use similar techniques to create the effect. A distortion pedal creates a clipping-type effect to distort or overdrive the sound.
In the early days of distortion, the effect was created by overloading an amplifier to cause the sound to break up.
The thing to remember is that the modern effects we use, whether digital or analog, have had hundreds and probably thousands of hours dedicated to crafting a sound that becomes appealing.
A similar theory is used, but you can’t expect to crank your channel level up to the point of no return and expect something that will match a plugin or pedal.
Is It Possible To Fix Clipped Audio?
There are fixes for clipped audio, although remember there is no guarantee of a completely clean fix.
If you still have the session in your DAW, look over your effects chain and try locate the culprits.
Is anything adding a lot of gain? Cycle through and turn each plugin on and off and see how this affects the levels.
Adjustments can be made with the track fader, but if you are really having to turn it down to avoid clipping, then there is likely something in the effects chain causing the majority of the issue.
Similarly, you can adjust your clip gain. This reduces the gain (and, in turn, the level) of your recorded track. This involves reducing the gain on the individual clip (as opposed to on the fader).
This process varies from DAW to DAW, but most will offer a clip gain function.
If you have bounced a stem or track and noticed some audio clipping, then there is software such as iZotope’s RX 10 De-clip plugin.
Whilst this works wonders, it’s still good practice to ensure no clipping on your tracks when bouncing them down.
I’d also mention that heavy clipping is very difficult to remove, so if this is the case, remember that it may not be possible to remove it without going back to the session and adjusting fully.
How Can I Avoid Audio Clipping?
If you’re mixing in a DAW remember that clipping doesn’t just occur on the track you are processing but also on the master bus (or the main output channel).
This channel is a sum of all the tracks combined in the session, so whilst you might have a lot of headroom on the individual components of the song, this could add up to cause clipping on the master channel.
Any effects that cause a significant boost in gain can all add to having clipping issues, so watch out for distortion, saturation, and compression plugins.
What Is The Difference Between A Limiter And A Clipper?
A limiter operates similarly to a compressor; however, their approach is much more ‘brick wall’ than compression.
This means that it is much more aggressive than a compressor, but its purpose is to push the volume of a track without causing clipping.
An audio clipper goes a step further and (as the name suggests!) clips the level of a track past a certain point, which in turn causes a distorted effect.
This is used tastefully and inserted into a signal chain to add character and punch.
While audio clipping, in general, is a no-no, using a soft clipping plugin can have a positive impact on your mix, such as on drums.
A limiter, on the other hand, doesn’t want to cause distortion. It will tame loud transients and is often used in mastering.
If you get distortion and ‘pumping’ effects with a limiter, you are probably pushing it too hard (unless that’s what you’re aiming for — then go nuts!)