Join Alex U. Case for an in-depth discussion in this video What is delay?, part of Foundations of Audio: Delay and Modulation.
Delay is likely the most underappreciated effects device we have in the recording studio. Until you've seen it and heard it in action, it's hard to imagine why delaying audio has any musical purpose. But believe me, it's rich with musical potential. However, before we get into the studio use of delay, let's talk a little bit about its origins. We've all heard echoes before. Shout into a tunnel, a canyon, or any large reflective space and whatever you shout bounces back. That's delay at work. Simple enough the audio signal, your voice, is delayed by some amount of time before being heard again later; an echo.
Delay, as an effect in music production, first came about by using well, slightly misusing analog tape machines, getting them to record a sound and then an instant later play it back. Throughout the 50s and 60s, tape-based delay became a staple of pop music and it became part of the signature sound of artists like Les Paul and Elvis Presley. Here we see an analog tape machine. Note the locations of the record head and the playback head. More importantly, recognize that there's a bit of distance between them.
To create a delay effect here, a signal is recorded at the record head, gets printed on to the tape, and with tape rolling, that recorded signal makes its way from the record head over to the playback head, taking time to do so. Finally, that signal is played back off tape. The result is a tape delay. The signal is delayed by the amount of time it takes the tape to travel from the record head to the playback head. The actual delay time then is a function of the speed of the tape machine and the particular make and model of tape machine which determines the physical distance between the two heads.
And here's what this effect sounds like. David: Hey Alex, how does this sound? Do I sound like Elvis yet? Alex: Yeah, David. Elvis, exactly. Let's do the hairdo next. We'll discuss how to create exactly this type of slapback effect echo later in the course. But to make the most of those audio examples, let's first discuss the fundamentals of creating delay effects.
- Adjusting the delay time, level, and feedback parameters
- Utilizing a low-pass filter and polarity reverse
- Setting up an effects loop
- Setting the delay time by tempo or by ear
- Understanding the distinct uses of short, medium, and long delays
- Adjusting modulation rate, depth, and shape
- Adding double tracking and spreader effects
- Manipulating tone with constructive or destructive interference
- Creating a comb filter and flange effect