Slap delay is one of the oldest and most-loved FX tricks in mixing history, dating back to Elvis recordings in the ‘50s. Learn how to harness this technique to bring out vibe, energy and emotion in your mixes.
By Slade Templeton
As far as delays are concerned, slap delay may be one of the oldest and most-utilized FX processing techniques since it’s conception. We’ll go back through the history of this effect, discuss all you need to know about slap delay and learn how they can best be utilized in a production or mix.
Echo vs. Slap Delay vs. Reverb
The first thing we should talk about is knowing what makes a slap delay a slap delay. It’s interesting to note that delays, echoes and reverbs are in some ways the same thing, but in other ways different, let me explain. An echo will be a short-range delay. The delays are around 30 to 50 milliseconds in timing. If you push it further, somewhere between 75-200 Milliseconds, you arrive into slap delay territory. And it doesn’t stop there. An echo is a spin-off of a delay, but with a delay, the effects can become a lot more than just an echo. Delays capture and time-shift the exact source sound, whereas the term “echo” applies more to specific types of sounds found in nature. It will echo when you yell into a canyon, for instance.
Then we arrive at reverb, which is the sound that comes from multiple and compact uses of delays or echoes and is the pulse of the sound that is perceived as “reflections.” It essentially comprises of many extremely small delays that can be less than a few milliseconds, in between the others, and is then perceived as a constant variable sound. So, to summarize, you can have a source sound, a delay of the source sound, which may sound like an echo inside of a deep canyon, and due to even smaller delays between it will result in reflections, which is known as reverberation. The delays can themselves have a reverberation of their resulting sound, as much as the original source sound can. These explanations help us better understand where all of this comes from. With the technicalities of what makes a slap delay a slap delay down, we can move into the history of the slap itself.
History of the Slap Delay
Slap delay became very popular in the early to mid ‘50s and was made famous by the King himself, Elvis Presley, and his engineer Sam Phillips. In many ways, this is one of the most well-known uses for slap delay still to this day. The biggest difference is that back then, they didn’t have plugins. They didn’t even have digital hardware that allowed for easy adjustments of delay to achieve a slap effect. They literally had to have two tape machines linked up, one that was recording the signal with a delayed offset of timing, and one that was the direct signal. Both units were mono and would receive the signal by two separate microphones (one delay mic, and one main vocal recording mic,) then play them through both machines consolidating back to one recording.
There was absolutely no room for error, and if they had too much slap level during a recording where the vocalist did a perfect take, well, it would be ruined and would need to be redone entirely! This illustrates just how essential the engineers were in the creation of the sound on any recording. This is the famous trick used at Sun Studios for many of the King’s songs and exactly where it all came from.
Modern Day Slap Delay
Slap delay wasn’t just a thing of the ‘50s, of course. The sound kept its life-force clear through the ‘70s, ‘80s, ‘90s and into modern times. The color of the slap and the techniques to get there were the main difference. The technology has evolved from using two massive tape machines in the ‘50s, to the 80s, where we started to see the use of digital delay units and solid-state delay units, to modern times where we use plugins such as H-Delay or tape emulation plugins like Kramer Master Tape or Abbey Road J37 Tape. Slaps were thrown onto vocals, synths, guitars, and so much more over the years; it is an endlessly useful effect. With the modern way of creating slap delays, we can add in the use of filters (high pass/low pass), automations, timing, width/stereo image adjustments, modulations, and even additional FX like we see on H-Delay with LoFi and analog settings to add extra grit and distortion or saturation. All these settings can be adjusted to add levels of depth to the sound source, causing different emotional responses in the listener. We’ll discuss some of these techniques.
Slap Delay: Adding Image and Depth
One of the best things about delays is that they totally inject a whole new attitude and vibe into your mixes and productions with a single instance of a plugin. It lets you turn an otherwise boring or stale vocal, or synth, into a unique and interesting sound. The feelings of emotion that slap delays can bring to an instrument or vocal can have a lot to do with the timing. If you make it slap a little faster than the tempo of the song, it will feel rushed and can help to create a feeling of energy and impact. While a little slower slap can make it feel a bit spacier and dreamy, giving it more atmosphere. You might even bring the delay time beyond that of a slap delay, but it works just as well. When we put a delay or effect onto an instrument, it adds that extra ‘edge’ and a certain coolness factor, and slap delays are a perfect way to do this. One of my favorite tricks is to use a slap delay on guitar as much as vocals to give it a very ‘80s sound, or even rockabilly.
Below is a vocal I recorded using Kramer Master Tape for the slap delay. You can hear just how it gives it a new flavor. This is a great way to add image and depth to your mix and production.
When we have slap delays adding image and depth to a song or instrument, we can take it a step further and push them a little more or less depending on where they are in the song’s timeline. We can even do this in real-time using automation techniques that are unique to the modern era.
Slap Delay: Automation
Automation can be used with plugins to give more control over what (or how much) slap delay you want sent through on an element in the mix. A great way to do this is by using an aux send to an FX bus. For example, you send a vocal into an aux, where you will put a full wet slap delay, and then you will automate the fader in and out to bring more (or less) slap into the big picture, depending on the section of the song. You may want more on the chorus section providing that extra lift, and less on the verse, keeping it more natural and intimate sounding. Automation can help you achieve that efficiently.
You could even put slap onto just a few words that you want to showcase and emphasize, riding the fader into the FX bus over certain phrases. I typically perform this at the end of the mixing process. When I am ready to get the final spice onto the mix overall, I will then ‘fly the faders’ and listen from start to end. At the moment I feel it, I move the delay fader up or down to give it a smooth and organic movement, much like playing an instrument. This goes back to that rush or dreamy feeling. We can add that into the song by doing automations to create a feeling of energy or a laid-back attitude. This doesn’t stop with slap delay either, you can do this with Reverbs and also other FX too. A combination of reverbs and delays are a great way to do this.
In this example, the dry voice from Example 1 is run through slap delay alongside reverb, both being automated to add movement and depth throughout the section. For the slap delay, the H-Delay was used, and for the reverb, I used R-Verb.
If you want to take it even further than just a delay and reverb, you can add in elements of saturation or distortion. This can make the song feel more aggressive and “in your face,” giving you even more impact to the effects you choose.
Slap Delay: Dry or Saturated
Saturation is such a great utility, and a little can go a long way. For instance, it can allow you to drive the delay or reverb even further, giving it a heavier presence and sustain. A good example of this is using saturation on a delay send, or a built-in saturation section of a plugin. On H-Delay, the LoFi and Analog sections add some of this extra fuel but also using a designated tape delay plugin such as the Kramer Master Tape, you can get even more of that retro grit making the song feel vintage with modern aggression. Another technique is to use a designated saturation plugin like Abbey Road Saturator, either before or after your delay on the same FX send. This will allow you to tune and tweak specific distortion characteristics appropriate to the song to your delay signal. You can then further tweak the color with EQ and create a truly unique slap sound.
Here is an example of using the Kramer Tape (only for saturation purposes; no delay activated) following the delay automation from Example 2. This helps drive the signal even further and puts more noise into your FX automations.
In the following guitar example, you can hear the slap delay set a tad longer. Just long enough to add groove from the plucking and performance. This is with both Analog Saturation from the H-Delay using Setting 3, along with the Kramer Tape to flutter between the more apparent delay slaps. I also added a touch of room reverb to give it a live ‘amp' feel. Even though this was performed as a direct input signal without an amp, you can feel it come alive and sound as if it’s recorded from an amp due to the nature of the reverb tail meshing with the two types of slap.
The modern ways of using effects make us realize how endless it can be and how far we can take it. Anything you dream of can be done with a few simple techniques and adjustments to bring emotion and elegance into your song. We can use this to bring great improvements to our mixes and productions. Spend the time tuning and tweaking some of that slap flare to your next production, and watch it open a whole new layer of possibilities!
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