What is Audio Distortion?
Audio distortion, like any audio effect, can enhance your film or video. Learn the ins and outs of using distortion to your advantage.
Have you ever wondered why distortion happens in your mixes or how it works?
Distortion can be both a benefit to your projects and a sign that the audio quality isn’t up to par. It’s definitely one of the most important things to watch out for as you’re editing audio and it’s a term you need to understand keenly.
Today we will discuss audio distortion, the effects it can have on your where and how to use it to make strategic creative decisions.
How Does Distortion Work?
The definition of distortion is the process deviation from the original signal. Distortion changes the waveform therefore the output differs from the input signal.
The cause of distortion is the overload of amplifying a signal. A loudspeaker or a microphone has a transducer that converts energy into another form of energy. In this case, it transforms electrical signals into mechanical movements to create sound. Pushing these electronics to the extreme can hinder the sound and cause distortion.
The most recognizable type of distortion is clipping. This is when the signal pushes beyond its maximum capability within its sound system. The tops of the sound wave essentially get “clipped” off, and as a result, it loses some of its data.
The result is a fuzzy and crushing sound that isn’t so pleasing to the ear. The speaker may be so loud that it becomes uncomfortable to listen to your music. In other instances, if you’re on a video call for a business conference, distortion from your audio feed isn’t so pleasing as you want your voice to sound as natural as possible. These are everyday examples of distortion.
When working in an NLE or Digital Audio Workstation (DAW), turning up the gain above zero decibels (dB) can create distortion. Zero dB represents the maximum capacity of a signal. Anything above needs care, as distortion may come into the mix. However, there are ways to creatively control distortion for an additional effect, rather than associating it with lousy audio quality.
Creative Uses of Distortion
In creative speak, distortion can be a positive thing. Electric guitarists heavily use distortion as it is a pretty iconic effect to add to a solo. They use an overdrive pedal connected to both the guitar and amp. The extra-gritty nature added makes it more exciting, becomes punchier, and just sounds plain cool!
In sound design, we can use distortion to enhance tension or creatively play around with the natural sounds to elevate a particular scenario. Playing with distortion can signal to the audience that a noise is loud.
Adding distortion to your mixes can add texture. Using this on a bass part can create more density, perfect for a more pronounced bass line. While it can make instruments sound heavy, distortion can also brighten sounds (on an electric guitar to make it stand out amongst the other instruments). Distortion can be used for Lo-Fi tracks and adding character to vocals.
In sound design, post-production may require you to add distortion to enhance a particular situation or even use it creatively to display a certain emotion. Meanwhile in filmmaking, ensuring the sound replicates what it would sound like in real life, so avoiding unintended distortion in production is key.
But it can open doors creatively, and can be striking. You may be making a sci-fi film and using distortion to replicate communications from outer space. Or, an individual could be playing around with a radio, trying to find the correct frequency to listen to a station. A character may be having a stressful experience, so to enhance this, adding distortion to amplify the surrounding sounds can create a more impactful scene.
Types of Distortion
Believe it or not, there are different types of distortion. Clipping is the most common. Clipping distortion allows non-harmonics to add color to the sound, while also making it seem like the sound is louder without increasing the peak level. It’s also called Overdrive, which is another common term for distortion and works by overloading the input gain for a crunchy sound. There is also a type of distortion that allows actual harmonics to shine and adds some character to your work.
Before discussing this distortion, let’s talk about how harmonics work. A harmonic is an overtone that occurs over the fundamental tone at fixed intervals.
Combining those harmonics with your original sound can make your mix sound less flat and add that extra punch. Saturation distortion adds harmonic frequencies to your mix. It’s great to use on drums or anything that’s highly percussive. Every sound naturally has harmonics but uses this process of bringing those harmonics to the forefront, hearing notes we wouldn’t have before in the dry signal.
Saturation is primarily used in music. However, a strong sound effect could use some saturation to add that extra impact and bring the sound more to the front of the mix.
This distortion is achieved by reducing the bit-depth, which can create a lo-fi sound. This process removes bits to decrease the quality. Use bit crushing with care. Taking away too many bits can make result in an unpleasant sound. Use this distortion in dialogue for that lo-fi and old-school effect.
Here is an example of bit crushing. If you’re aiming for that gaming world sound, a bit crusher is a way to go.
Although this may not be a typical distortion, it still is classed as one! This effect can increase and decrease the pitch of a sound source when approaching and then passing the listener.
An excellent example of this is when a police car drives past. When driving towards us, the higher frequency pitches reach our ears as the sound waves are compressed by the car moving forward. When it moves away, the waves are stretched out, resulting in a lower pitch. You can play with various parameters such as the distance of the sound source, direction, and starting point of the sound.
Amps magnify the signal from the guitar to amplify the volume. This is in reference to amplifiers used by instrumentalists, especially guitarists.
On amplifiers, you can alter the treble, mid, and bass. By playing around with these, you can create distortion. These are also available digitally on DAWs to recreate the sound of a real amp. These also add weight, and you can use them on any instrument or sound.
Like any audio effect, distortion has parameters to get the sound you want. Here are a few of the more common parameters you may come across when using distortion:
The Amount is one of the most common and indicates how harsh the distortion will be. This is rather similar to the parameter Drive. It will either determine the input or output gain and will saturate the sound depending on how much you set it to. The lower the setting, the softer the sound. The higher the setting, the harsher and fuller.
Filter controls what part of the frequency spectrum you’d like to add distortion to. You can apply to distort on only the lower end or higher end for a more precise distortion. This works similarly to an equalizer, but will only have a high and low cutoff filter.
Dry/Wet is on all audio effects and is a must when mixing. This determines the mix between the dry signal and the distorted signal (wet). You can keep it subtle by having more of the dry signal come through, or keep it heavy by having more of the wet signal for a more impactful sound.
On many DAWs, distortion plugins will have presets so you can adjust to your needs. Playing around with the parameters that are already in place can make finding your sound a lot easier.
While distortion may be a negative when trying to achieve absolute realism in your sound design, it can offer you a whole new creative approach. If you are a beginner guitarist, get an overdrive pedal, which will ultimately make your practice sessions much more fun! Distortion can provide that extra depth and grit to those moments of tension and chaos.
All images via Sashatigar.
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