Knock around with musicians long enough and you’re bound to get drawn into conversations about effects – when to use them, how to achieve them. So it’s best to know the basics, such as what is the difference between echo and delay.
Both are great ways to add depth to a track and have been extensively employed by top guitarists including David Gilmour and Brian May. Delay has been used since the days of reel-to-reel tapes, while echo emerged as an audio effect in the late 1950s.
Delay
Delay is separate, but recurring, copies of an original signal, usually with a delay time of over 35 milliseconds. The original sound is stored and played back in different ways depending on how the settings have been programmed. The effect, which can be preset or user configured, can even be achieved with just one repeat but usually multiple repeats are used.
It is possible to recreate the sound and feel of the earlier tape and analog effects using modern equipment with appropriate modes. Users can also make the effect bounce between two channels or even create a new sound. Delay is much more than echo, and adds ambience to a track.
Types of delay
The effect started on tape. Originally it was made using two heads on a tape recorder, one recording and one for playback. With this format, delay was increased by looping the tape around other objects such as a microphone stand. Tape delay is now available as a delay plugin effect, which is much simpler and takes a lot less space in the studio. The original effect using reel-to-reel tapes is still preferred by some musicians though.
Straight delay is where the effect is applied to the original signal so it comes back and reinforces it. It is not mixed with the original source, but used to create a sense of space and depth. Because of this, it is often used in choruses and by guitarists to amplify their solos.
Slapback delay is a single echo effect which returns milliseconds after the output. Both guitarists and vocalists use it. The guitarists can add a dreamy effect to their solos and the vocalists are able to add effects such as ad-libbing.
Multi tap delay is a series of delays. These can be set to recur in tempo with the tune or to use a specific timeframe. Each recurrence of the delay can have different effects applied to it. This use of the effect adds ambience but it can also be used for rhythmic repetition.
Echo
An echo effect is created when sounds are delayed enough to be heard as separate sounds, with repeated decaying effects. Echo is technically a subset of delay, usually a slapback delay with added repetition and decay.
Echo, as might be expected, is a straight copy of a sound, looping a single delay multiple times. It can be used for lead vocals to repeat a word or phrase that needs emphasis. Pink Floyd’s song Echoes uses the effect on guitar.
The usual convention when using this important effect is to employ delay before echo, although reversing the effects creates a muddy sound. The choice of how to incorporate delay and echo into a composition is down to the musician, but the effects will be noticed by many more people than just the composer.
