As I recently covered in my overview on the many types of delay, slapback delay is a relatively quick, single echo/reflection which originated in the rock records of the 1950’s and has a number of uses. Here we’re going to drill down on slapback delay, talking about the specific settings to use to create it in your delay, and more importantly when and how to use it in your mix.
Slapback Delay
First let’s cover the slapback delay settings which make a slapback what it is and give it its unique tone.
Slapback Delay Settings
When talking any delay settings, we’re mostly focusing on three parameters: time, feedback, and mix.
Time
Slapback delay’s actual delay time is relatively short. Generally spanning 60-200ms after that initial sound, you can adjust this to make whatever you’re applying it to sound larger to give it more presence.
I’ll talk about using slapback on vocals in a moment, but adding more time to the delay time makes that vocal sound like it’s coming from a larger space which can give it a lot more size.
A longer/slower delay time for slapback works well for some mixes, particularly those which have a slower tempo.
For a more uptempo mix, you’ll likely want a shorter time closer to 60ms so that it doesn’t step on the next note or hit.
Remember that when you go too much shorter than 60ms, you start approaching the realm of the Haas effect. Also known as the “precedence effect”, this principle explains that if two instances of the same sound are played at roughly 40 ms or less apart, the human ear perceives them as one sound.
The separation is what creates the “back” in slapback, after all.
Feedback
The “Feedback” parameter on delay creates additional reflections at a diminishing level after the initial reflection.
Setting this to 0% means that you get the one echo and that’s it.
Begin to roll this higher and you’ll hear more echos with a longer “decay”.
Setting this at 100% creates a feedback loop to where the echos just keep building (possibly deafening you or destroying your speaker in the process if you’re not paying attention!).
With slapback delay, we’re generally keeping the feedback at or near 0% because it’s just about that initial echo.
Slapback delay is one of the cleanest delays by reputation as a result of this because there is little to no decay tail in the form of feedback echos.
If you want to try dialing this up to 10-15% to add a little sustain via an extra albeit tiny additional amount of echo then you can experiment with this, but zero feedback is typically the way to go with slapback delay – just that single slapback echo ringing out before it cleanly disappears.
Mix
The “Mix” parameter on a delay dictates the ratio of the volume of the delayed signal to the initial signal.
At 50%, you’re hearing the echo ring out at the exact same volume as the initial sound. At 0% you’re hearing no echo, and at 100% you’re ONLY hearing the echo (which just means you’re hearing your audio on a delay).
The wet/dry on slapback delay will especially be to taste, but 50% is a good starting spot before bringing it down and comparing it to 40%, 30%, and 20%.
You generally don’t want to exceed 50% as this would make the echo louder than your initial signal itself. Outside of some very specific aesthetic effects, odds are this isn’t what you’re trying to accomplish with slapback.
How to Use Slapback Delay
Now let’s talk how to use slapback delay on different instruments.
Vocals
One of the better rock records of this century in my opinion is The Gaslight Anthem’s breakthrough 2008 record “The ’59 Sound”.
One of the hallmarks of that record (along with the exclusive use of clean guitars) was the generous and frequent use of slapback delay on vocalist Brian Fallon’s vocals.
If you are familiar with that record and love it as much as I do, there’s actually a very interesting oral history of the record done by The Ringer which talks a bit about the use of slapback on his voice.
Ted Hutt, the producer, put the effect all over the vocals to kind of go with the theme of the record, that sound of rock and roll in the late 1950’s when Sun Studio was using it on everything, most famously on the vocals of Elvis Presley.
But I digress – if you listen to the above clip you’ll hear it’s a relatively short delay time given the tempo of the track. It gets very close to that Haas effect territory where the slapback on the vocal sounds like an extension of the vocal itself.
There’s a little bit of feedback if you listen closely; it’s not an immediate drop off.
I estimate in terms of settings it’s at or just under a 50% wet to dry mix, a delay of about 60-80ms, and a feedback of 15-20%.
The effect is that it thickens out the vocal and gives it some more size and presence in the mix as you get a little bit of that bounce from the feedback.
This is just one specific example to show that slapback delay, in the right mix and context, can sound epic.
Guitar
Slapback delay sounds great on guitar either clean or lightly distorted especially, and in certain genres like country, blues, and rockabilly in particular.
You generally don’t want to use this when you’ve got a busier mix with a lot of guitars or instrumentation in general fighting for space in the mix.
Slapback on guitar works much better in a sparser mix where you’ve just got one or two guitars, bass, drums, and your vocal.
Like with the slapback on vocals, you want to keep the feedback relatively short to keep from overlapping on and cluttering up the sound. You also want to keep your delay time relatively short, though this will vary with the tempo of your song.
Unlike that specific vocal example I gave earlier, you probably want to dial down the mix setting to a more subtle 25% as a starting point. It’s more of an accent here rather than an equal, so that 25% keeps it visible in the mix while keeping it in its more supporting role.
Snare
Like with an electric guitar, slapback delay on a snare can make it sound bigger in the mix.
We’re going on the short side here with slapback on a snare, staying in the 60-100ms range getting just the edge of the precedence effect.
The mix should be especially low so that we’re not hearing the separation or echo so much as we’re just hearing more sustain on the back end of the snare. We also want to keep the feedback at 0% here as we don’t want any (further) reflections.
This same use of slapback can be applied to virtually any track/instrument in your mix, leads, pads, strings, other percussion (even your kick!).
Experiment with slapback delay in your mix to add some size and or sustain without sacrificing clarity like you run the risk of doing with reverb.
Also don’t forget to check out my other tutorials on using delay in your mix.