March 15, 2012 § Leave a Comment
An Overview of Audio Effects
This week we’re taking a step back to the basics in order to give our beginner readers an overview on audio effects and how they work. If you’re just starting out on your audio production journey, you’ve most likely come across effects in your gear or software. These might be delay, reverb, distortion, compression, phase, flange, pitch-shift, ring modulators or filters. This article aims to get you familiar with these terms and what these devices do. In future installments of this series we will get a bit deeper on specific types of effects (as some subjects such as reverb require an article of their own.) For now we begin at the beginning…
What are Audio Effects?
Audio effects are devices (analog or digital) that are used to intentionally alter how a musical instrument or other audio source sounds. Effects can be subtle or extreme and they can be used in live or recording situations. A good example of audio effects are the “stomp-boxes” that many electric guitarists use to realize their desired sound. By chaining together many different types of effects units a musician can sculpt a unique tone. Almost all popular music benefits from creative use of effects, the only exception being an all-acoustic show (and even then there are usually effects involved). All commercial music is enhanced with effects and electronic music makes liberal use of these devices. With proper use they can really enhance your sound and take the listener to new sonic spaces.
A Brief History of Audio Effects
Modern day effects are all a result of the evolution of technology and the advent of recorded sound. Around the Mid 1940’s recording engineers started to use reel to reel tape machines to create delays, echos and sound effects. In addition to tape, microphone placement and movement were found to create sounds that had not previously been recorded. In 1948 Harry DeArmond, creator of the first guitar pickup, created the first stand-alone effects processor called the Trem-Trol by running the electric current of the signal through liquid to create a tremolo sound. This device was used by Bo Diddley and led to more development in the guitar industry of the 1940’s and 50’s where guitar amplifiers started to introduce vibrato and reverb effects. Reverb was initially created by driving an electrical signal into a metal plate or spring to create multiple echos or reflections of a sound.
Back in the studio, recording engineers started to use echo chambers to create echo effects or a unique tone to their recordings. Echo chambers were usually long, low rectangular spaces made from sound-reflective materials such as concrete. They were fitted with a loudspeaker at one end and a microphone at the other to create an echo effect that was used on many recordings to enhance vocals. As they were often custom-made, these echo chambers became the sound signature of a given studio at that time. As technology developed, many reverb devices allowed for electronic re-creation of the echo chamber effect. Equalizers and compressors arrived in the studio in the 1950’s and 60’s with the Pultec equalizer which defined the sound of many recordings of that era.
Hardware and Software Effects
Today audio effects devices come in both physical and digital form. Audio signals in electrical format are processed with physical (analog) hardware whereas audio signals in binary format (digital) are processed mathematically by software. Both methods can achieve similar results. In the physical world, effects are usually rack-mounted devices that have cables running to and from a mixing board or they can be something like guitar effect pedals which receive signal from the instrument and alter the signal as it flows to a mixer. On the digital side you can find effects in most music recording software packages. DAWs such as Ableton, Logic, Cubase and ProTools all come with audio effects built-in. Other software packages likeReason, Maschine, Traktor, Audacity, Peak, and Soundforge also come with audio effects. Audio effects are often simple devices that do one specific thing to a sound, although multi-effects processors are also popular for those who want many different effects in one package. It is also worth noting that many instruments (especially synthesizers) come with effects built-in to the machine. (read more)