We’re here to help! Call 1300 858 395

Audio Effect Types & Their Uses

Audio effects are everywhere. They are layered through contemporary music, used to create vivid worlds for the screen, and underpin the helpful sounds which signpost our day-to-day lives. And yet, even seasoned musicians often only have a general understanding of what audio effects actually do to a signal. In this guide, we break down common effects and discuss their uses in a variety of situations. Whether it's leveraging your pedalboard for a sharper guitar tone, digging through your DAW for the perfect plugin, or patching a synth module for abstract chaos, we'll talk through the important points to help elevate your experimentation.

Fender Squier Bass

What are Audio Effects?

Audio effects take a signal and process it to change some of its characteristics. This could be as simple as a subtle volume boost over certain frequencies, or as complex as projecting the signal into an virtual space and resampling the sounds that reverberate past an imaginary microphone. Audio effects often split a signal into 'dry' (unaffected) and 'wet' (affected) paths which can then be blended back together to taste.

What types of audio effects are there?

Dynamic Effects

Compression, Limiting, Noise Gates, Expanders

Dynamic effects process an audio signal in response to amplitude level. They are the most powerful tools at your disposal for making mixes sound consistent with themselves and with recorded music in their genre. Dynamic effects 'correct' signals, give them body, and make them pump ... or completely destroy them if you overdo it.

Compression takes the loudest parts of a signal and makes them quieter while increasing the overall volume of the signal itself. This 'squeeze' reduces a signal's dynamic range, making it easier to mix. It also enriches harmonic content, adds sustain, and increases perceived volume and presence. A little bit is good on just about everything.

Limiting is an extreme form of compression that essentially stops a signal's volume level from going above a certain threshold and subsequently allows you to increase the overall volume.

Limiting can 'fix' a signal that is too hot, but it's best used on rough mixes and final masters to safely push the volume up to a broadcast standard.

Noise gates are 'upside-down' limiters which reduce the quietest parts of a signal. This is great for eliminating unwanted ambience, electronic hum, or instrument tails, as well as subtly breathing fresh space back into tracks dense with sound. For guitarists and bassists with hot effects chains, noise gates are essential items.

Expanders do the opposite of compressors, making loud parts louder and quiet parts quieter. This 'stretches' a signal, adding dynamic range and cutting down unwanted noise. They are great for adding life to vocal and instrumental tracks, as well as cutting down on mic 'bleed' when mixing a live drum kit.

For more info on compression, check out our Compression Explained article.

Seymour Duncan pickup on a Gibson guitar

Distortion Effects

Saturation, Overdrive, Distortion, Fuzz, Bit-crushing, Boost

Distortion effects produce harmonics by removing parts of a signal to create a new waveform. This is either through pushing a circuit past its regular operating level, or judiciously chopping squarish bits out the signal proper. Distortion is no-nonsense vibe with the power to excite any instrument into a cooler, grittier version of itself.

Saturation adds warmth to a signal by producing even-order harmonics. Saturators tend not to dramatically change the character of a sound, making them perfect for use on vocals, drums, and other acoustic instruments. Add saturation to synthesisers, vocals and masters to breath 'life' and 'feeling' into them.

Overdrive produces more extreme even-order harmonics by pushing the signal and having it soft 'clip' the loudest parts. Overdrive was born in 1940s tube amps and it remains a crucial element of any electric guitar effects chain. A little works well on most things: dirtying up synths, 'compressing' vocal shouts, and making snares 'sizzle'.

Distortion is overdrive through the lens of solid-state transistors. It creates 'hard' clipping, which results in odd-order harmonics for considerably more aggressive signal alteration.

Distortion is a rock guitarist's best friend, makes bass lines writhe like demon worms, and generally adds crackle to whatever you put it on.

Fuzz takes the transistor angle runs with it. It mangles a signal into a unique, 'squarish' waveform and then uses a frequency multiplier to add complex harmonic overtones. Fuzz beautifully disintegrates synth patches, 'digitises' percussion into moody samples, and is of course one of the guitar's most iconic effects.

Bit-crushing is a unique distortion effect that lowers the number of volume levels available to express an audio signal. This 'down-sampling' of the bit-rate creates a 'pixellated' sound full of harsh edges and strange artefacts. Bit-crushers are perfect for dark synths and industrial percussion, or for 'chip-tuning' lead guitar.

Boost is simply increasing the volume level of a signal. While not a distortion effect itself, placing a boost in front of a clipping circuit allows you to tailor how much of the signal gets cut off and turned into harmonics. Try placing a boost in front of your tube amp, dirt pedals or fuzz boxes for wild results (just remember to start small).

Fender American Ultra Bass switching system

Spectral Effects

Equalisation, Band Compression, Pitch Transposition, Harmonisation

Spectral effects allow you to analyse a signal over the whole audio spectrum and then change specific parts of it. Any effect can have a spectral variant, but those which fine-tune amplitude and pitch are by far the most common and useful. Spectral effects 'fix', enhance, or completely warp a signal with surgical precision.

Equalisation is gives you control over the relative volume level of different frequency bands. These could simply be a predefined low/mid/high, a complex line graph, or individual Hz. Use equalisation to cut unnecessary frequencies and free-up space in a mix: cut highs from kicks, lows from snares, and mids from your master.

Band compression is a handy effect that allows you to compress a specific range of frequencies. This is perfect for ensuring the 'transient', the initial attack of an instrument, gets through the compressor unchanged, while the falling 'tail' is sustained. Try band compression on vocals, percussion, and acoustic instruments.

Pitch transposition (AKA pitch shifting) moves the perceived frequency of a signal to a different point on the chromatic or microtonal scale. This could be auto-tuned 'correction', 'octave' up/down, or repitching for new timbres. Auto-tune speech into vocals, repitch drums to make new kits, or detune synths for extra width and power.

Harmonisation identifies a signal's pitch and then creates duplicates at different points in a scale. This can quickly create chords, harmonies, or blistering walls of atonality depending on what you feed in. Harmonisers are powerful effects for solo vocalists, a shortcut for electronic producers, and fundamental to octave fuzz.

Fender American Ultra Bass switching system

Stereo Effects

Auto pan, Stereo Imaging, Parallel Imaging, Mono Summing

Stereo effects move sounds left and right in the stereo field through a combination of physical panning between speakers and psycho-acoustic tricks. They add 'width' to a mix when there is asymmetry between the two speakers, or 'phantom mono' when the signals are identical. Use stereo effects to help craft the space your music resides in.

Auto-pan lets you apply automation to the stereo positioning of a signal. It 'crossfades' the percentage split between the left and right speakers over a user-defined time, subdivision of the tempo, or other modulation source. Use it to create rotating soundscapes, a sense of movement, or to draw the listener's focus.

Stereo imaging widens (or narrows) a signal through panning as above, but also through the use of psycho-acoustics. By doubling a mono signal, placing it left & right, and subtly delaying one side, stereo imagers create 'phase cancellation'. This tricks our brain into thinking the sound comes from beyond the 90-degree width of the speakers.

Parallel imaging is actually a technique that mimics the effects of a stereo imager. By following the above steps in your DAW, you can achieve similar results without having to load up another plugin. The power of parallel imaging is that you can process each side of the image separately, and exert greater control over the subsequent soundscape.

Mono summing is a simple utility effect that takes a stereo signal and converts it to mono. This is invaluable for preventing unwanted phase cancellation on crucial elements of a mix. Use mono summing on stereo samples, especially kick and bass, or on the master to check for unwanted noise, phasing, or other 'frequency-crowding' problems.

Fender American Ultra Bass switching system

Filter Effects

High Pass, Low Pass, Band Pass, Notch, Wah-wah, Auto-wah

Filter effects remove a certain part of the frequency spectrum from a signal. They can also boost the area around their cut-off frequency to dynamically highlight revealed harmonic content. The design, 'slope', and components of a filter can make them behave in unique and flavourful ways that differentiate them from more sterile equalisers.

High Pass filters cut off low and mid frequencies, allowing higher-pitched content to 'pass' unaltered. As high frequencies contain much of a sound's 'energy', high pass filters are great cleaning up mixes without sacrificing intensity. Use HPFs on metallic sounds, techno snares, or even a little on bass lines to raise them above a low kick.

Low Pass filters cut highs and mids and let low frequencies pass through. Low-pitched instruments transmit 'groove' but often come with unnecessary higher frequencies. Throw LPFs on kick and bass to make them felt rather than heard, or on noisy guitar and synth lines to calm them down and reveal interesting harmonic overtones and textures.

Bandpass filters cut both highs and lows while allowing an 'ant hill' of sounds through around whichever frequency band you 'sweep' to. This is usually in the low- or high-mids where a lot of percussive instruments have their transients. Experiment with bandpass filters on toms, traditional percussion, and found sounds.

Notch filters (AKA band-stop or band-reject) flip bandpass filters upside down and cut frequencies in a small 'ant ... valley' while allowing lows and highs to pass through. They are very similar in function to using a banded EQ to clean up a signal. Use notch filters to remove unwanted resonances from samples, room sounds or synth patches.

Wah-wah is a resonant filter that sweeps across a portion of the frequency spectrum. This creates a 'spectral glide' effect where the timbre of the instrument changes while the perceived pitch remains the same. Apply wah-wah to the lead lines of guitar, keyboards, or brass to make them more expressive and draw the listener's attention.

Auto-wah (AKA an envelope filter/follower) is a resonant filter that reacts to the volume levels of the input signal (or sometimes an LFO) to control the frequency sweep. This occurs at a speed that would be physically impossible for a human to emulate. Play rhythmically into auto-wah for extra 'funk', or smoothly for interstellar shimmer.

If you'd like more information on filter types, their uses and some audio examples check out our Filters Explored article.

Fender American Ultra Bass switching system

Time-based Effects

Reverb, Digital and Analog Delay, Echo

Time-based effects copy a signal and delay the onset of the subsequent signal to create variations on the echoes which naturally occur in nature. They can range from perfect digital replications to muddy after-effects with little relation to the source material. Time-based effects add 'depth' to a signal and are thus crucial mixing tools.

Room reverb takes a physical (or algorithmic) room with desirable sonic characteristics and projects a signal into it. A microphone then captures the resultant sound as it bounces around the angles and surfaces. Room reverb is great for giving a signal a sense of space that it may not otherwise possess.

Plate reverb trades a room for a literal (or virtual) sheet of steel held aloft by tense springs. A special transducer projects the signal onto the metal plate and another picks it up again. The unnatural sound of plate reverbs is perfect for blending with room reverb, creating bright 'slapbacks', or building alien soundscapes.

Spring reverb uses the same principle but with a tense spring strung inside a sealed 'tank' (or an emulation thereof). They tend to have a dark, 'bouncy' tone with a lot of low end. Use spring reverb on moody (especially surf) guitars, layer it on room recordings for extra vibe, or smash it with noise to create shuddering thunderstorms.

Convolution reverb takes the vast power of modern Digital Signal Processors (DSPs) uses it to create Matrix-esque simulations of physical (or imaginary) spaces. These possess far more detail than algorithmic room reverbs though may not be as 'musically-tuned'.

Convolution reverbs are perfect for SFX, dark electronic music, and 'live' emulations.

Digital delay records a signal and plays it back for a defined number of repeats at defined volume levels. The 'perfect' nature of these repeats gives them an unnatural quality that can turn a mundane signal into a new instrument. Experiment with digital delay on mid-/high-register electronic sounds, clean guitars, or abstract vocals.

Echo seeks to better mimic the dark, degraded repeats found in nature through the use of analogue tape machines or bucket brigade devices. Their analogue (or emulated) nature creates imperfect repeats heavy on 'colour'. Apply echo to lead lines to add space around an instrument while keeping the original signal in the foreground.

Ping-pong delay is a type of stereo delay that uses an LFO to pan the delayed signal left and right at defined intervals. This creates width whilst also drawing the listener's attention to the 'moving' signal. Ping-pong delay adds rhythm to percussion, fractures vocals, and turns pads into a seething sonic confluence.

Asynchronous delay is another stereo delay that places its repeats to the left and right. The difference is that the left and right signals have separate parameter controls so they sound like two unique delays. Use asynchronous delay to disorientate listeners as instruments get locked in evolving patterns of call and response.

Fender American Ultra Bass switching system

Amplitude Modulation

Tremolo, Flange, Phase, Ring Modulation

Amplitude Modulation effects increase and/or decrease the volume of a signal over a specified time period. This is through applying an LFO to either a VCA or the delayed double of a signal, or through mathematical multiplication. Amplitude modulation is inherently rhythmic as it either accents or 'ghosts' certain notes or phrases.

Tremolo applies a Low Frequency Oscillator directly to a Voltage Controlled Amplifier handling an incoming signal. This can produce swells and fades, angular chops and drops, or AM synthesis at audio-rate frequencies. Use tremolo to animate stale drum patterns, create 'helicopter' guitar chords, or produce pulsing electronic glitches.

Flange mixes the original signal with a delayed double which has an LFO applied to the delay time (usually within 0-20 ms). The resulting 'comb filter' effect creates new peaks and notches that are swept over the frequency spectrum and often 'fed-back' into the input. Use flangers to create 'drainpipe', 'wind tunnel', and 'jet engine' sounds.

Phase mixes the original signal with a delayed double which has a (generally quite slow) LFO applied to the delay time. It's notches and subsequent phase-cancellation are then created by a series of all-pass filters (stages) applied to the delayed signal. Use phase for robot voices, jet-stream guitars, and morphing percussion.

Ring Modulation multiplies the original signal by a second signal (usually a basic waveform) and outputs the sum and difference of the two. This inverts the waveform and completely overwrites the timbre of the original signal. Ring Modulation creates characteristic 'metallic' tones that are great for rhythm but are melodically unwieldy.

Fender American Ultra Bass switching system

Frequency Modulation

Chorus, Vibrato, Pitch Shifting, FM Synthesis

Frequency Modulation effects increase and/or decrease the pitch of a signal over a specified period of time. This is achieved through applying an LFO to the pitch of the original signal or a delayed double. Frequency Modulation effects change the timbre and 'vibe' of a signal without drastically altering its emphasis or timing.

Chorus mixes a signal with a slightly-delayed second signal, to which an LFO modulating the pitch has been applied. This creates a 'shimmering' effect as subtle phase cancellation occurs between the two signals. Add chorus to long notes for a dreamy quality, to short notes for vibe, or to vocal takes for extra strength and body.

Vibrato also uses an LFO to modulate pitch, but only of the original signal. It produces a 'warbling' effect which can become quite choppy as the rate of the LFO is increased. Apply subtle vibrato to voices and instruments to emulate acoustic vibrato techniques or warped records, or crank the depth to create underwater ray guns.

Pitch Shifting (AKA pitch transposition) is a broad term under which effects like vibrato fall. It's included here to represent the extreme pitch effects available to synthesists who apply modulation directly to the frequency of their oscillators. Use pitch shifting for dizzying soundscapes, evolving timbres, and emergent melodies.

FM Synthesis modulates the frequency of an audible signal (the carrier) by an inaudible one (the modulator). It is useful for creating timbres that are difficult to achieve with other forms of synthesis. Explore FM for bell-like percussion, glassy electric pianos, and cutting kick and bass that's one knob turn from atonal madness.

Fender American Ultra Bass switching system
Woman recording on mobile phone

End of the Signal Chain

This concludes our top-down look at audio effects. Stay tuned as we update this page with links to new articles discussing each effect type in more detail. If you have any questions about the effects described above or signal wrangling in general, contact our friendly music experts for some industry-tested advice.

Check out our range of both rack mount and stomp-box style audio FX by visiting us in store or shop online!

Hear about it first!