In Pads 101 we discussed the general nature of the pad sounds and their use in worship but how exactly do we get great pad sounds? It’s fine enough to use or modify one of the thousands of pad patches in your keyboard or software, but why not program your own? Learning a little synth programming will train your ear to listen for different types of synthesis when you are picking apart those album tracks and will help you to be more efficient when you are modifying other patches to be closer to what you want. Besides, it’s fun to use something you’ve made yourself!
We are going to be following along with this tutorial (you’ll have to forgive me, I made it pre-blog so the numbering doesn’t quite work). I’m going to give some additional pointers here. By the end you should have a new pad that is all your own!
Choose a sound type to start with
Subtractive synthesizers generally have a common architecture that begins with the oscillator. The oscillator (abbrev. osc) is a basic waveform that we can modify by cutting out parts of it or adding other waveforms to make a more complicated waveform. Different waveforms have different timbres as a result of the number of harmonics, whether or not the harmonics are even or odd, and how much of the fundamental tone is present. Some of your common choices are:
- Sine wave: A pure sine wave carries the fundamental without any harmonics.
- Triangle wave: A triangle wave is often the closest we can get to a sine wave in digital land. Mostly fundamental with a few harmonics.
- Sawtooth Wave: Tone with all harmonics present.
- Pulse wave: Fundamental with odd harmonics. Sounds “cold.” Length of the pulse affects the amount of harmonics. A 50% pulse wave is the same as a square wave.
- Noise: Pure noise. Can help add some high frequency content or “Splash.”
Set up your Amplifier Envelope
Envelopes are time/intensity parameters that we establish to modulate or change other parameters. Customarily there will be an envelope on every synthesizer to change the volume of the sound over time and we call this the amplifier envelope. Envelopes usually have at least 4 elements:
- an attack time which controls how long it takes for the envelope to reach maximum intensity
- a decay time which controls how long it will take from the end of the attack until the sustain intensity is reached
- a sustain intensity control which determines the level of the sustain phase
- a release time which determines how long the envelope will continue after the keys are released
In terms of an amplifier envelope these controls affect volume. For our pad patch we generally want a slow-ish attack and a slowish decay into a sustain that is relatively loud and a medium release. A patch with this type of envelope will fade in and then fade down to the sustain volume and persist for a bit after the keys are released.
Stop! Filter Time.
Filters are the core of subtractive synthesis and come in a few varieties:
- Low pass filter – lows PASS through, highs are trimmed off. The sound will be duller, more muted, or softer. The number assigned to the filter describes how aggressively the frequency trimming happens – a 24 db/octave removes twice as much high end as a 12 db/octave.
- High pass filter – high frequencies PASS through so the sound is brighter and shriller.
- Band pass filter – a limited range of frequencies pass through removing some of the high AND low end.
- Notch filter/Band Reject – Some of the middle frequencies are removed leaving BOTH the high and the low end.
- Cutoff Frequency – the frequency at which the filter starts to have an effect. Common target for modulation with an envelope or LFO.
- Resonance – the filter self-oscillates creating a sine wave tone at the set frequency of the filter. Useful for adding back some high end or drawing attention to the cutoff frequency.
Arguably the low pass filter is the most used and is what we are using in this tutorial. Turn the cutoff frequency down to wherever you like it. A more open sound with the cutoff frequency higher might do for a chorus or upbeat song, a filter that is more closed might be nice for a ballad or down-tempo part of the song. Add resonance to taste (or not).
The “motion” or evolution of the sound that holds your interest is usually accomplished by changing the above parameters either with another envelope (which we don’t have in the video tutorial) or with a LFO or Low Frequency Oscillator. The LFO is a special oscillator that we can give different waveforms and speeds and then target to synthesizer parameters like cutoff frequency, pitch, volume, resonance, or others depending on the synthesizer. In the tutorial the “Speed” control refers to the rate of the oscillator and in this video the “Vib/Wah” knob refers to the targets of oscillator pitch (Vib) or frequency cutoff (Wah). Your synthesizer of choice may give you many more destinations for the LFO so feel free to try them out!
The Effects are the Icing on the Cake
There is not enough space here to go into depth on the effects we can use to give some more character to our pads but feel free to try some out. A few of my favorites include:
- Chorus – Combines the sound source with a delayed version of itself for some phase cancellation. Adds color to the sound.
- Delay – gives the sensation of space while keeping a lot of the character of the initial sound. May use with or without reverb.
- Reverb – gives the sensation of space without repeating the original sound. Often the character of the reverb becomes part of the “sound” itself. You can change the amount during the song to send a pad to the background (more reverb) and bring it back again (less reverb).
What are your pad construction tips?
I’m curious to know what you would include in a pad construction kit or which are your favorite techniques? Let me know in the comments, and as always thanks!