A Beginner's Guide to Audio Effects.

You’ve just finished recording your vocals, you’ve just nailed your drum pattern or you think you’ve finally finished filling out all the parts in your track but it just isn't sounding there yet... You need to find a way of sprinkling some magic on your tune and there’s only one thing for it: audio effects. We’ve all been there before: mindlessly turning dials and moving sliders without really knowing what sort of effect you’re going to have on your beloved creation. Before you enter another arbitrary value in a random box, we’re here to give you a hand.

NB: you should see this article as more of a glossary of audio effects; we’ll be looking at the individual effects in more detail in future Connects.

Equaliser or EQ

Influence the frequencies of the audio signal with an Equaliser. With this tool you have the ability to cut or reduce certain frequencies to prevent mudiness or get rid of that one tone that's really bugging you. Alternatively you might want to boost  certain frequencies to bring out some hidden juice in the sound.  You might inclined to boost the high end to make some vocals sound more crisp or you might want to dip the mids to make a mix sound less bloated. I often like to increase the high frequencies of my vocal recordings by a decent whack to make them pop but that can depend on what microphone you're using to record. Just by playing with the frequencies of individual instruments or vocals in a track you can really change the colour of the whole piece. Like so much of what can be changed using effects though the outcome, or desired sound, is largely down to taste.

Compressor

The easiest way to describe compression is that it levels out volumes in a particular signal; making the louds quieter and the quiets louder. If a vocalist has recorded a particularly soft vocal a compressor can be used to give the recording more presence amidst the track. If a compressor is used on the entire track then it will attempt to even out all of the track’s component parts - reducing the effect of those sounds that particularly stick out.

Be wary of using a compressor on a quiet signal though as it will bring out all of the quietest “background” sounds that you might not necessarily want in the finished track. If you smack your lips a lot while recording vocals you might want to use a noise gate first (see below). The ideal effect of using compression will make the overall sound that bit punchier and more crisp. I've recently starting messing with multipressors; these allow you to apply compression to different frequency bands found within an input signal. That way I can compress the highs differently to the lows.

Limiter

Limiters ensure that an audio signal doesn't clip by limiting the volume to a certain threshold - the signal is simply not allowed to exceed the imposed limit. Limiters and compressors are similar in that they adjust the volume of a signal but limiters are more basic in that they solely apply a top volume limit. You can adjust the threshold that you want the limiter to kick in at so it's only in effect at certain high volumes. For example, if we set the threshold of a limiter at -2dB it will only come into action if a particular sound attempts to exceed that volume. The limiter will then keep that particular sound at -2dB. Limiters can also be used in mastering when an engineer is looking to increase the overall average volume of the track... but that’s a story for another day.

Filters

Ever want to make your song sound like it’s coming from next door? That’s filters, friend. Okay so that’s just an example of one specific filter - the low pass filter, a filter which doesn’t allow high frequency sounds through - but it's one that has been hugely prevalent in EDM music for decades now. Filters essentially do what an EQ does - they remove certain frequencies from a sound. The way that a filter affects an audio signal is determined by the steepness and the shape of its slope alongside the chosen cutoff frequency.

Filters are widely used by DJs and producers to make a transitionary section in a song, a ‘build up’ or even the intro, feel muted and like it’s leading us to something bigger. There isn’t much more satisfying than a beat transitioning in and out of a filter. They aren’t just used for arrangement/creative reasons though; you can massively fine-tune the feel of a specific instrument or even a specific part of a drum kit by applying a filter. This is definitely an effect that lends itself to experimenting with the inputs until you find a shape and sound that you're happy with.

Noise Gate

A fairly straightforward one here. Noise gates allow you to mute low level signals, such as room sounds or breathing, to ensure that any gaps remain silent. Similarly to a limiter you are able to set a threshold but here it works in the opposite sense: any sounds that are quieter than a certain dB value are cut out from the outputted signal. When a sound is louder than this threshold the “gate” opens and allows the sound through.

Delay

Delay is essentially copying the original signal and repeating it - a form of echoing that can be fine tuned to perform in whichever way you think suits the sound best. Just calling delay an echo though doesn’t quite do this effect justice though; delay can be used to thicken a sound by doubling it up like chorus, fill a gap in an arrangement by adding a diminishing delay to some guitar or vocals or create interesting rhythmic synth lines by overlapping multiple delays at once. You won’t find many vocal lines in modern music that don’t have some form of delay applied; even just a very subtle addition of delay can liven up a dead sound.

Reverb

Whether it’s a cathedral, a swimming pool or an office - you can re-create the acoustic dynamics of a space by applying reverb to an audio signal. These days many DAWs (Digital Audio Workstations) can emulate a huge list of spaces through its reverb plug-ins. Reverb takes an audio signal and places it in a space to reverberate around, creating various types of echo and a sense of space and distance. This can add warmth to you track and make a sound feel fuller. Fiddling with the controls within a reverb plug-in can be helpful though as sometimes a sound can get pushed too far into the background by applying a large amount of reverb. Sometimes you’re better off using a smaller, brighter reverb if the goal is to make a signal more present in the mix. You also might not want to use the same reverb plugin on every part of a track - try experimenting with different reverbs on different instruments.

Distortion

Sometimes you've just gotta add some crunch to that guitar and raise the horns. Distortion can be used to make a signal sound more raw, gritty and dirty...so to speak. It essentially makes the signal clip by pushing up the gain but is simultaneously compressing it so the volume isn’t increased. There are various ways in which distortion is achieved and they all have different effects on the sound; some add warmth where some add harmonic distortion. Whichever type of distortion you use, whether it be bit-crushing or tube distortion, it will add intrigue to the clean signal, giving it more body and making it feel fuller.

Panning

Another fairly simple one on the surface but panning can actually make a huge difference to the feel of any track. In practical terms you are simply adjusting controls found in mixers to dictate how much of an audio signal is fed to the left or right stereo outputs. Just how much signal you send to the left or right affects the placement of the sound in the stereo soundstage. You can picture the soundstage as a 3D space around your head with the left and right channels being equivalent to your left and right ears. DAWs will largely default a track to be central in the mix i.e. directly in the centre of the left and right channel. By altering how each individual audio signal is panned you fill out the mix and avoid sound clouding each other. Giving an individual instrument its own space in the stereo soundstage can really help to draw attention to it while not getting in the way of other sounds. Alternatively you can place sounds close to each other if you want them to blend and overlap. You can also use panning automation to pan a sound at a particular moment in your piece from left to right, or vice versa, to create a sense of movement and add some interest. If you’re looking for a much faster and more intense version of this sensation you could try using a tremolo effect.

Tremolo

Tremolo creates a pulsating effect by using an LFO (Low Frequency Oscillator) to rapidly alter the volume of an inputted audio signal. You can affect how the tremolo alters the sound by adjusting the rate (how quickly it pusles) and the depth (the difference in volume or the intensity) of the effect. Tremolo is perhaps most prominent as a guitar effect, creating that wavy and mysterious sound, but it can be used in any setting to create tension or rhythmic intrigue.

Chorus

Chorus is related to delay in that it creates a copy of the audio signal but it does some specific things to the copied audio. By adding some pitch alteration, and in some cases some stereo panning, Chorus can thicken a sound and make it harmonically different to the original. Hugely prevalent in the 1980s, think the vocals on Ashes to Ashes by David Bowie, chorus can be used for multiple reasons: softening an instrument’s tone, beefing up a lead vocal (while making it sound less natural) or making a bass sound fatter and meaner. It's also an easy way of turning your speaking voice into Darth Vader's (assuming you already have the bassy tones of James Earl Jones).

Flangers and Phasers

Flangers and phasers operate in a similar fashion to chorus but on top of the original clean signal they apply modulation and feedback to obtain a sweeping effect that, bare with me, creates a similar sensation to that of an ambulance siren (UK siren - not sure about international siren sounds). Obviously this effect can be widely altered to create the effect you want but in general it has a swooshing, underwater feel to it with phasers being a mellower choice out of the two. Fancy adding some psychedelic, Tame Impala feels to your track? Flangers and phasers can get you there.

There are plenty more effects out there and many of the ones listed in this article have their own offshoots and variations to explore. Like I said at the start though this is by no means a ‘how to’ piece and more of a ‘getting to know you’ sort of thing. In all honesty, the best way of discovering what effects do is just by diving into your DAW and having a play. You can create your own sound just by recording, layering up effects and adjusting the knobs and dials until you’ve arrived at something you like. Chances are if you’re learning how to directly emulate a certain sound then you’ll be missing out on sparking some real originality.