Delay Effect Basics What You Need To Know

Novice audio engineers and the home studio enthusiasts may have heard about the concept of ‘Delay’ in audio recording. In this article we will try to uncover this technique in more detail. Delay is basically an artificially created audio effect.

Delay records an input audio signal and writes onto a storage medium to be played back after a time interval. This delayed signal is then played back for multiple times as preset or can be played back again into the recording in order to create the effects of a decaying echoes or a chorus.

How Delay Was Created?

At earlier times, delay had been created using tape loops on reel-to-reel magnetic recording systems. Then the composers started using elaborated systems like long tapes and multiple recording and playback systems. Music audio engineers adopted similar techniques in order to augment their plate reverb usage.

Later with analog technology, usage of multiple playback heads made it possible to create delays at rhythmic intervals. Old analog-type delay systems like Echoplex and Roland Space Echo are still being used by modern bands to create some unique effects.

In 1980s, the advancement in digital signal processing led to the development of digital delay processing. Digital delay functions by sampling the input signal through an analog to digital converter and then the signal is passed through a series of signal processors.

The audio is played back based on the user-set parameters. The most advanced digital systems now allow the users to have more fascinating controls like adding an audio filter or reverse playback of the buffer content etc.

Why Do We Use Delay With Audio?

Delay is the technique, which acts as the basis of several different unique audio effects and it can transform the audio from being dull and amateur to a well-treated and professional audio tracks.

Echoplex is a type of delay used to create multiple echoes, getting synchronized with a musical rhythm. Doubling echo and slap-back echo are also effects created by delay.

In 1980s, Irish guitarist The Edge was well-known for the usage of slap-back delay as a unique melodic device. Chorus, flanging, and reverberations have also delayed-based audio effects which are widely used.

The Basic Parameters of Delay and How They Work

There are different parameters for different delay processors. The three major and universal delay parameters are time, feedback and effect/mix level. We will discuss here a few other common parameters.

• Mix is the parameter which controls the effect’s output level. The higher this parameter is set, the louder the delayed signal will be.
• Gain is another parameter, which lets you to set the signal level that goes into the delay.
• Low-pass filter (LPF) parameter is used to filter out high frequencies from the delay.
• Depth is a parameter letting you to add different modulations to the delay in order to create a chorus effect.
• Rate parameter allows you to adjust the amount of time and the modulation.
• Feedback is an important parameter, which controls the number of times an echo is repeated.

Types of Delay

The two major types of delays are analog and digital.

Analog Delay

It was the first type of delay used in audio engineering. The effect was created using magnetic tapes for recording and playback. The type of tapes used to create this effect will wear out after a certain period and needed to be replaced from time to time. Apart from tapes, some analog delay systems used magnetic drums and discs as a storage medium.

Digital Delay

It is a modern technology introduced in late 1970′s, but was very expensive during that time. BOSS DD-2 changed this situation and made it cheaper in the form of affordable foot pedals.

The basic working principle of digital delay is by sampling a bit of audio and then playing it back based on set parameters. Digital delay is the most accurate and effective mode, but some people believe that digital delay is creating more of an artificial effect when compared to the old-age analog process.

Practical Application of Delay in Music Production

In popular music, electric guitarists and keyboard players etc. use the delay effect to produce thickly overlaid notes, creating dense rhythms. Vocalists and other instrumentalists also use the same technique to bring in ethereal quality in their voice while singing or playing instruments.

Long-range delays of 10 seconds or even more are frequently used to create loops of whole musical phrases. On the other hand, doubling echo is usually produced by using short-range delay to the recorded sound. The most common type of delays used is of 30 to 50 milliseconds and longer delay duration becomes a slap back echo. Mixing up the original track and delayed sound can create a unique effect which is similar to unison or double tracking performance.