Six Practical Uses For Delay

Usually, the best workflow for delay plug‑ins involves using an aux send to bus audio from the source track(s) to a dedicated mixer channel hosting the delay.

Everyone loves a good delay effect. But when you’re mixing, delays can do more than you might imagine...

We all know what a delay effect is. But do you really appreciate just how much you can achieve with delay in your own productions? In this article, I’ll run through some common but sometimes misunderstood techniques. I’ll work back from the intention, explaining not only how to get there using any suitable tool, but also why it might sometimes deliver a better result than alternative techniques.

Reverb serves to push a source further ‘back’ in the sound stage — not what you want for parts that need to remain front and centre! In these cases, delay can work better...

1. Size Without Distance

This first scenario will help you get your head around some of the basics of setting up and manipulating delay effects. Suppose you want to make an important element in your mix (such as a lead vocal, electric guitar part or synth line) sound bigger and more impressive. A natural first impulse (sorry!) might be to use reverb, to create some thickness and a sense of space. Indeed, that might work well. But often, reverb also serves to push a source further ‘back’ in the sound stage — clearly that’s not what you want for parts that need to remain front and centre!

In these cases, delay can work better. Reverb creates a dense collection of reflections that suggest an acoustic space. Delay, being simpler, can still place supporting energy behind the dry sound but without conveying so much spatial information. Adding pre‑delay to a reverb (another simple delay effect!) can separate the dry sound from the reverb tail, and this works very well for preserving a sense of immediacy. But the acoustic cues remain. When you feel they aren’t appropriate, why not try delay instead of reverb?

The aim isn’t necessarily to make the sound ‘wider’ but simply subjectively ‘more impressive’, and while stereo width is related to size, the two are not the same thing. A very basic mono delay is often enough to support and reinforce the dry track. For this application, avoid very short delay times, and a tempo‑synchronised delay can work extremely well — for example try a quarter‑note delay.

Although such a delay can be used as an insert effect, there are practical benefits to setting up a dedicated track in your project for each delay (or, for that matter, reverb), and sending the signal to it using the source track’s aux send controls. Except where you have a specific reason not to do so, I’d advise working that way.

On the effects track, set your delay effect to 100 percent wet. Then, getting the wet/dry level right by balancing your source and the delay is crucial. A good rule of thumb is to bring this delay up using the aux send control until it’s clearly audible when played in the context of the rest of the of the track, and then back it off slightly. It shouldn’t sound too obvious, but you should certainly feel the difference when it is muted.

How clearly the delay effect is heard is also closely related to how clearly the delay repeats its input, and typically, while you’ll want the main source to remain present and up front, it helps if the repeats themselves retreat a little. A bright, full‑frequency digital repeat will compete with the dry source more than a ‘darker’ one will. This is something you can only really judge by ear in the context of the full mix.

If the delay sounds too bright, consider using a low‑pass filter to remove an appropriate amount of high‑frequency information from the repeats. This could be on a dedicated delay track in your project, before or after the delay. Or, if the plug‑in offers it, you can filter the repeats in the delay’s own feedback loop, so each generation gets a little darker. High‑pass filtering can be useful too, to prevent a build‑up of low‑mid muddiness and, if taken further, can impart a more telephone‑like quality to the repeats.

Some delays will do this naturally, due to their design, and it’s often a good application for modelled analogue delays. A tape delay, for instance, is inherently somewhat darker than a digital delay. My own preference is often for a bucket‑brigade delay emulation — BBDs, as they’re often known, can be wonderfully lo‑fi, with their characteristic analogue ‘munge’.

With the timing, tone and level in place, three or four repeats from a mono delay may be all a featured instrument or vocal needs to open up the arrangement for a big chorus. Try it on its own, or along with reverb.

2. Thickness With Slapback

Another way to add thickness to a sound is a ‘slapback delay’. A prominent slap immediately evokes early rock & roll or a John Lennon vocal. It is a great effect, but a distinctive one. Used more subtly, it simply makes a vocal feel less naked and exposed: a common problem, particularly for self‑producing artists.

In the same circumstances, you might instinctively reach for reverb. But, as discussed, reverb comes with psychoacoustic baggage. Slap delay is an alternative that can often create extra energy behind the dry sound.

Slap delay is usually a short mono delay with a single repeat, making it one of the simplest ways to thicken a sound. Its short duration means it’s less likely to get in the way than a longer time‑based effect. In fact, I think of it as occupying similar territory to double‑tracking (whether real or the ADT effect), but offering a different flavour, with an inescapable nod towards early rock & roll.

That association exists because slapback was one of the earliest widely used delay effects — largely because the equipment needed to create it was already present in even the most rudimentary studios. Audio is recorded onto tape and reproduced a short time later by a separate playback head, the delay time being determined by the tape speed and the distance between the heads.

There is therefore no single ‘correct’ delay time for slap, although there are certainly times that are too short or too long to produce the characteristic effect. Depending on the machine and tape speed, the resulting delay would commonly fall somewhere between about 80 and 150 milliseconds. For example, on my own tape machine (a quarter‑inch two‑track Akai from the early ’70s, running at 15 inches per second) the distance between the heads means the delay time is around 85ms. Greater spacing between heads causes a longer delay. So too will slower tape speeds, but that can change the sound character too.

Look through the slap presets in a selection of delay plug‑ins and you will find a range of delay values, then, but they will generally occupy the same broad window. Note that slap isn’t normally tempo‑sync’ed, and that this single, short, slightly out‑of‑time repeat can often sound odd when heard in isolation (ie. with the part and the effect soloed together). However, thousands of classic records demonstrate that when used appropriately and judged in the context of the full mix, it can work extremely well....