Delay is a powerful mixing tool for adding width, depth and dimension to your tracks. However, sometimes it can be difficult to dial in the sound in your head—especially if you're not used to working with delays. In this blog, we'll break down everything you need to know about mixing with delay, including the basic controls, how to set the timing, and tips for achieving different effects with delay.
What Is Delay?
Delay is an audio processing technique that records an input source to a storage medium (like a reel of tape or a hard drive), then plays it back after a user-defined period of time. Depending on the parameters, the signal may repeat once, or multiple times, and can even be fed back into itself to create a decaying echo effect.
Delay can be a great way to add space to a track without taking up much room in the mix. Much like reverb, delay can be used to push a track back in the mix and create the illusion of depth. It can also be used to make tracks sound wider by using a stereo delay on a mono signal, or panning the delay to the opposite side of the mix.
Finally, delay can be a great way to add rhythmic excitement to your track. Whether you're adding subtle ambiance to simulate an acoustic space, or creating trippy Radiohead-style delay loops, delay can be a potent form of ear candy that catches the listeners' attention.
History of Delay Units
Originally, delays were created using analog tape loops: a technique developed by Pierre Schaeffer the 1940s. Tape loops are created by splicing a section of tape end-to-end, which can be looped to playback continuously. The length of the loop controls the length of the repeated sounds.
At first, tape loops and delays were used to create unique rhythms, textures, and timbres in the form of musique concrète. By the 1960s and 70s, popular artists began experimenting with analog delay units to create interesting new sounds that fueled the psychedelic, progressive and ambient genres. Some of the most popular examples of early tape delays are the Echoplex EP-2 and the Roland RE-201 Space Echo, popularized by Brian Eno.
Boss released the DD-2, the world's first digital delay pedal in 1984, ushering in a new era of time-based effects. Digital delays offer more sophisticated and complex effects than traditional analog delay, such as reverb, time-stretching and even pitch-shifting.
Delay vs Reverb
At this point, you may be wondering about the differences between reverb and delay. Both are time-based effects, but they add depth and space to mixes in different ways.
Technically, reverb is a form of delay. What you're hearing is the sound of a delayed signal being played back in a reverberant space, which colors and smears the sound. All reverbs are delays, but not all delays are reverbs.
Traditional delays simply repeat the original signal without simulating what it would sound like in an acoustic space. Others color the sound with different materials like magnetic tape or different types of metal, but they don't smear the time element like reverbs do.
Most delay units feature pretty straightforward controls. The first is Delay Time, which is typically measured in milliseconds. This controls how long of a delay there is between the source signal and the delayed signal. You can set the delay time manually (by ear), or use some simple math to figure out the perfect timing.
There are 60,000 milliseconds in a minute. To determine how long a beat is based on the BPM of your song, use this formula:
60,000 / BPM = one beat in milliseconds
For example, if you're working on a track that's 120 BPM, one beat is 500 ms (60,000 / 120 = 500).
Thankfully, most delay units also include a Time Sync feature, which automatically syncs up with the BPM of your track so all you have to do is select the note length. In addition to standard delay durations like 1/8th note, 1/4 note and 1/2 note, most delay units also allow advanced note durations like dotted notes and triplets.
One of the key elements of delay is Feedback, which controls how much of the signal is fed back into the delay unit, and ultimately how many times something is repeated. When feedback is set to 0%, the signal is repeated once. When the feedback is set to 100%, it creates an infinite feedback loop—so be careful!
Additionally, many delay units include tools for sculpting your sound, such as high and low cut filters. These can be used to remove unwanted low-end or roll-off the high-end of a delay to help push the back in the mix and create space.
Some delay units include Rate controls, which adjust the rate at which the modulated signal oscillates. Turn up the rate to create a "phasey" sound that can be used to create different types of effects (more on that later).
Finally, the wet/dry controls adjust the balance between the original signal and the delayed signal. When using an effects send, it's best to use 100% wet and 0% dry to retain complete control over both signals on separate faders. For one-off effects like throw delays, you can add the plug-in directly to the channel and adjust the wet/dry controls to taste.
Types of Delay Effect
If you've heard one delay, you've heard them all, right? Wrong.
Delay units are actually capable of creating a variety of different effects based on which settings you use. In addition to the traditional delay or echo that occurs when we hear a signal delayed by more than 50 ms, delay units can also be used to create phaser, flanger and chorus effects. These effects delay the signal by such a small amount that our ears can't separate the original from the duplicate, which helps to beef up the sound.
Phaser effects delay different frequencies by varying amounts, which creates a rolling, kind of underwater sound that works well for beefing up thin guitar tones. To create a phaser effect, set the delay time at 0 ms (or as fast as the plug-in will allow), and crank the rate controls to increase the amount of modulation. The rate controls adjust how much the signal oscillates, or how quickly it sweeps through different frequencies.
Flangers are similar to phasers but sound a little more obvious and apparent in the mix. They work by mixing an LFO into the original signal to create a shifting or sweeping sound across the frequency spectrum. Flangers are typically used to make instruments sound thicker or simulate a doubling effect.
One common mixing technique that uses a flanger is called the Haas Effect, or the Precedence Effect. This technique is typically used to convert a mono track to a stereo track by duplicating the signal, running it through a flanger or short delay (typically 1-5 ms), and panning the two signals hard left and right.
However, since the delay is so short, our ears perceive both signals as one sound—the original. The duplicated track adds space and depth without becoming overpowering in the mix.
Another common type of effect created using delay is Chorus. Similar to a flanger, choruses use slightly longer delays (typically between 5 and 30 ms) to simulate the effects of double tracking. Chorus effects use LFOs to introduce subtle variations in pitch and timing to make it sound like you recorded multiple takes.
Chorus effects are commonly used to thicken up keyboards and clean guitars, and were a staple on just about every instrument in the 80s. Chorus effects also work great on vocals—especially for making background vocals and stacks sound huge!
Tips For Using Delays While Mixing
Unless you're using a delay unit to simulate one of the time-based effects listed above, the biggest decision you have to make is how long to set the delay time. First, decide on if you want to sync the delay to the tempo of the track or free-hand it.
Synching the delay to the BPM is a great way to add width and depth without taking up too much space in the mix. This technique works well in busy tracks and is a great alternative to reverb, which can easily muddy up your mix.
You can also set the delay time manually, either by using the equation outlined above or by ear. When setting the delay time by ear, you'll never get the timing perfect—and that's actually kind of the point. Setting the delay time by ear tends to cause the delay to stick out more in the mix, which can be a cool effect in itself.
Next, adjust the delay time to get the sound you're looking for. Remember, the human ear has a hard time separating the delay from the original source with delay times below 50 - 100 ms. Just remember—shorter delay times tend to make tracks sound bigger, while longer delay times push a sound back in the mix.
Really short delay times (like eighth note and below) cause a tight slapback sound, similar to a short chamber reverb. This effect was especially popular in the 50s and 60s and was a staple of Elvis' vocal sound.
Quarter note delays are commonly used on vocals and work well for filling out the space. One of the most common techniques is to set up a quarter note delay on an aux send, with the return levels just barely audible. Then, adjust the feedback until the number of echoes fills the space between each vocal phase. It may take some tweaking to get it right for each track, but this is a great way to add depth to a lead vocal track.
If the rhythm of the vocal changes throughout the song, the delay may get in the way of the vocal. To correct this, add a compressor after the delay plug-in. Set the side-chain so the compressor is triggered by the vocal track. Tweak the threshold and attack controls so that the compressor lowers the level of the delay whenever the vocal is playing. Finally, adjust the release time to prevent any unnatural pumping effects. This will ensure the delay and the vocal are always present but never competing.
Half and whole note delays are typically used as "throw delays," which only occur once or twice during a song to draw attention to a certain word or phrase. Oftentimes, stereo delays are used to make the vocal sound larger than life. For an extra-trippy effect, use slightly different delay times on the left and right channels. Not only does this create an ultra-wide stereo soundscape, but it can also be used to create an immersive ping-ponging effect.
No matter what type of delay you use, it can be tough to get time-based effects to sit right in the mix. It's always best to use a shelf EQ like MIXROOM and BASSROOM to sculpt the sound of your delay returns. Try cutting any necessary low-end to prevent muddiness, and rolling off the highs for a classic tape-delay effect.
Use these techniques during your next mixing session to dial in professional-sounding mixes with mesmerizing delays!