Last Updated on February 27, 2020 by Facundo
Anyone who is new to audio engineering has probably asked this question at some point since it’s a fairly common one.
Reverb and delay are two of the effects that are probably used to the most when producing any kind of music and you should know exactly what each of them does and also when to use them, since this can be even more confusing.
In this post I will go over what each of these effects does, what the differences are, their similarities and when to use them.
Table of Contents
- What is a Delay?
- Is an Echo a type of Delay?
- Short Delay
- Long Delay
- What is a Reverb
- Different Types of Reverb
- What do Delay and Reverb have in Common?
- What are the differences between Reverb and Delay?
- How do you know when to use each one?
- The number one rule when applying Reverb and Delay
- Start with Reverb
- Reverb can muddy things up, that’s when you use Delay
- When to use Delay?
In order to better understand how the Reverb and Delay effects work and when to use them, we first need to look at what both of them are.
For practicality I’m going to start with the Delay first;
What is a Delay?
A delay is nothing more than the same original audio signal being repeated again and again after a short period of time.
The number of times the signal is repeated is called feedback.
This means that the more feedback, the more the signal will be repeated, which basically means than this effect will carry on for longer.
Is an Echo a type of Delay?
Some prefer not to call a delay an echo, but it’s basically what it is.
If you’ve ever seen a movie where they yell something in a mountain range and you could clearly hear the same words that were yelled repeat over and over again just farther away, then this would be how a delay works.
An echo is just a sub-set of a delay; repeat the same signal over and over while lowering the amplitude for each repetition and you got yourself an echo.
When you’re using a delay in a DAW or a Delay pedal for an instrument, everything can be configured differently; You might want the delays to slowly die down, like in those movies, or not!
Short delays are usually classified into Doubling Delays and Slapback Delays;
A doubling delay is usually produced by adding a 20-40ms delay to a sound. Any longer than 50ms and it would be considered slapback delay.
A doubling delay, when mixed with its original source, gives a similar effect as doubletracking, which is something commonly done with vocals.
If you want to know more about how to mix double tracked vocals, read this guide I wrote on that topic.
Like I’ve just explained, to be considered slapback delay, the delay time has to be longer than 50ms, as a rule of thumb.
Slapback delay is usually around 75-250ms with little feedback (feedback is the number of times the signal is repeated).
This was used a lot on 1950’s rock-n-roll records, especially on the vocals, because without delay, or echo, the recordings would lack realism and delay helped them achieve this more “realistic” sound.
A long delay, as the name implies, has a very long delay and also high feedback and is more commonly used for rhythmic playing.
If you’ve ever seen the Queen Concert at the Wembley Stadium, there’s a solo that Brian May plays called Brighton Rock Solo which uses a lot of delay with plenty of feedback.
If you haven’t seen it, I’d highly recommend you check it out since it’s absolutely fantastic!
What is a Reverb?
Reverb is something we interact with each and every day.
It’s when the soundwaves bounce off every surrounding surface and then reach our ears at slightly different times.
This gives us the perception of space when hearing.
We are, in fact, quite used to this but the issue arises when we record music, since the techniques used to do this tend to emphasize removing as much of the external acoustics as possible because it allows us to better capture the sound source.
We try to avoid picking up as much of the room’s acoustics as possible so we can better edit those sounds after. THEN we add Reverb to give that sense of depth and space.
Reverb can also be viewed as a lot of differently timed delays with different feedbacks which sort of “blur” together, giving the perception of space and depth.
The different types of reverb
There are basically 5 different types of reverb; Room, Hall, Chamber, Plate and Spring.
The Room Reverb is just that; It sounds like a room and the decay time is very short.
The Hall Reverb emulates how Concert Halls sound, which are designed to sound as tonally even and perfect as possible.
The chamber Reverb sounds like a large room typically designed for orchestras but isn’t as large as the Hall one.
The plate and spring reverbs are man made and use a metal plate or a spring that vibrate and create the reverb.
What do Delay and Reverb have in Common?
Both of them are time-based effects which process the signal altering it in different ways, even though they may be very closely related, they are not the same at all.
Flanging, Chorus and Reverb are all delay-based Effects actually, but with Flanging and Chorus, the delay time is short and, in many cases, modulated.
When it comes to reverb there are multiple delays and feedback which make the “echoes” blur together, making it sound like an acoustic space.
A Reverb would be, in some sense, a lot of different simultaneous delays which end up recreating a room or any other acoustic space.
So, back to the question at hand…
What are the differences between Reverb and Delay?
Both are time-based sound effects but delay is the repetition of the signal after a breve period of time and the number of repetitions depend on the feedback.
Reverb is the natural result of soundwaves bouncing off every surface, hard, soft, tall, short, etc. that we then hear and perceive as the room’s acoustics.
Imagine you were in a HUGE and empty room and you decided to clap your hands.
First you would hear the direct sound of you clap, because it’s what’s closest to you.
But after a breve moment, the sound of the clap bounces of the walls and reaches your ears. This would be considered as Delay.
BUT those soundwaves will continue to bounce everywhere and start to die down. This would be considered reverb.
How do you know when to use each one?
This is a complicated question with no right answer since it depends entirely on the genre and the song you’re producing and also on how YOU want it to sound.
The number one rule when applying Reverb and Delay
Subtlety is king when adding reverb and delay.
You usually want them to create the feeling of space and depth, which means that you should be able to notice when these effects are there, or when they aren’t, but they shouldn’t be overpowering.
If you feel like you can hear them too much, or if they distract the listener from what’s really going on in the song, just dial it down.
This is by far the most common mistakes beginners make and it’s a tough balance to achieve.
Start with the reverb
If you find yourself asking the question whether you should start with one or the other, I think the best choice would be to start with reverb.
Again, Subtlety is King.
Don’t go overboard with the effect and don’t use a lot of different reverb types. You probably don’t need different reverbs for drums, vocals, guitars, etc.
The whole point of reverb is to make the music sound as if it was being played in a room, you want to be able to hear the ambience.
Using 3 different reverb types won’t sound natural.
Usually you are going to want to add a reverb type that’s actually similar to the room where the music was recorded in.
If everything was recorded in a small studio, you should first try adding a room reverb and not a huge hall one.
Note: This isn’t set in stone, it’s just a basic guideline, you should still play around to see if you find something you like since the only real judge here are your ears.
Reverb can muddy things up, that’s when you use delay
Reverbs have tails, which in some cases can be great for a mix, but they can also cause more harm than good in a lot of situations.
I usually run my vocals, guitars, synths, snares, and cymbals, or any other instruments not on the very low end of the spectrum, through the same reverb, at least at first.
I avoid adding reverb to the bass and kick drums because this will, in most cases, generate a lot of mud.
Low end plus reverb adds to the muddiness, remember this.
When to use Delay?
Of course, delay can be used simply as an effect, like the one I described earlier about Brian May which would be a completely different use than trying to generate a similar effect to what a reverb does.
But a delay can do a lot of similar things that the Reverb can, like giving that sense of space and openness.
If you feel like the Reverb you added isn’t really giving you the sound you desire, or is muddying the track up, or if the mix just sounds washed up, then you should try some delay.
Like I mentioned earlier, reverbs have tails on them which can cause more harm than good sometimes, delays don’t!
That’s when a delay comes in handy since it doesn’t add that tail to the signal, avoiding certain problems.
Adding a short slapback delay may be all you need, or maybe a good stereo delay can give your tracks the same sense of space a reverb can without adding any of the muddiness.
A longer stereo delay can make the guitar and background vocal tracks sound much softer and open.
Learning how and when to use each of these effects is something that can only be achieved through practice and repetition.
However, I hope I was able to give you some pointers on when and how to use them, at least to make the whole learning process faster and avoid some headaches along the way.
I hope you have a wonderful day!
Until the next one!