Sound Design and Comparing Synths

Building a Patch from Scratch

Every subtractive synth patch follows the same process, whether you’re working on a hardware Moog or a software plugin:

1. Choose your waveform. This is your harmonic starting material. Sawtooth for rich, buzzy sounds. Square for hollow, woody tones. Triangle for something softer. Sine for purity. Noise for texture. You can often blend two oscillators together — say, a sawtooth for body and a noise generator for breath.

2. Set your filter. Low-pass is the default starting point. Sweep the cutoff knob down from the top until the sound has the right amount of brightness. Add some resonance if you want emphasis at the cutoff point. This is where the subtractive philosophy lives: you started rich, now you’re shaping.

3. Shape the amplitude envelope. Fast attack for percussive sounds, slow attack for pads. Short sustain for plucks, full sustain for held tones. Adjust the release to taste — short for tight, long for atmospheric.

4. Shape the filter envelope. This is where character emerges. A fast-attack, quick-decay filter envelope makes the sound burst open and settle — the classic synth pluck. A slow-attack filter envelope creates a gradual reveal. The filter envelope amount knob controls how dramatic the effect is.

5. Add modulation. LFO to the filter for movement. LFO to pitch for vibrato. Unison for thickness. Glide for expression. These are the finishing touches that take a sound from “functional” to “alive.”

That’s the process. Five steps. Everything else is refinement — adjusting knobs until it sounds right. Sound design is less about knowing the “correct” settings and more about understanding what each parameter does so you can move toward the sound in your head.

Beyond Subtractive: Other Synthesis Methods

Subtractive synthesis — what we’ve been learning — is one approach: start with a harmonically rich waveform, filter it down. It’s the most intuitive method and the one you’ll use the most. But there are other ways to build sound, and knowing what they do (even broadly) helps you choose the right tool.

FM Synthesis

Frequency modulation synthesis doesn’t start with a complex waveform and subtract. Instead, it takes simple waveforms (usually sine waves) and uses one to modulate the frequency of another — extremely fast, at audio rates. The result is new harmonic content that doesn’t exist in either waveform alone.

FM creates sounds that are bright, metallic, bell-like, glassy — tones that are difficult or impossible to get from subtractive synthesis. It’s the signature sound of the Yamaha DX7 and a huge chunk of 1980s pop, R&B, and jazz fusion. FM synthesis is powerful but notoriously hard to program by ear, because small changes to the modulation parameters can produce wildly unpredictable results.

Wavetable Synthesis

Instead of a fixed waveform (saw, square, sine), a wavetable synth gives you a table of many waveforms arranged in sequence. You can scan through them — either manually or with an LFO or envelope — and the waveform itself morphs over time. This creates evolving, shifting timbres that change continuously even on a sustained note.

Wavetable synthesis occupies a middle ground between subtractive and FM: it’s more sonically diverse than subtractive (because the waveform itself changes), but more predictable than FM (because you’re scrolling through known shapes rather than modulating frequencies).

Granular Synthesis

Granular synthesis takes a different approach entirely. It chops a sound into tiny fragments called “grains” — sometimes as short as a few milliseconds — and reassembles them in various ways. You can stretch a one-second sample to fill a minute without changing the pitch, or pitch-shift it without changing the length, or scatter the grains randomly to create textural clouds.

Granular is less about “playing notes” and more about transforming existing sounds into something new. It’s the synthesis method most closely tied to sampling, but with a level of manipulation that goes far beyond pressing play.

Why We Bother

Why don’t we just sample everything? Because sampling gives us something static. Musical sounds are expressive because they change dynamically. Different forms of synthesis give us radically different options to play with — we can take the things they do and manipulate those things musically in ways that aren’t just the same beep and boop every time. (For a deeper take on this question, see the Who Needs Synthesis? article.)

You don’t need to master FM or granular for this course. But knowing they exist, and roughly what they do, will help you understand why certain sounds are built with certain tools — and why some synths are better suited to certain tasks than others.

The “Analog Warmth” Discussion

We covered distortion and saturation as harmonic addition in Chapter 3 — the opposite of subtractive filtering. That concept is the key to understanding what people mean by “analog warmth.”

You’ll hear producers talk about “analog warmth” — the idea that hardware synths, tape machines, and tube preamps sound “warmer” or “fatter” than their digital equivalents. What are they actually describing?

A few things, usually:

• Low-order harmonic distortion: Analog circuits naturally add small amounts of 2nd and 3rd harmonics. This is technically distortion, but at low levels it’s perceived as fullness and warmth.
• Component drift: No two analog circuits are perfectly identical. Slight variations in capacitors, resistors, and transistors mean each unit sounds slightly different — and those differences accumulate into a quality that’s difficult to replicate digitally.
• Noise floor: Analog equipment has a noise floor — a low hiss that’s always present. In small amounts, this can feel like “air” or “life” in a mix.

Is analog “better”? That’s the wrong question. Analog and digital are different tools with different characteristics. The point isn’t to fetishize one over the other — it’s to understand what you’re hearing when someone says “warm” and to know which tool gets you there.

What to Practice

• Take any subtractive synth and build three patches from the default initial state: a plucky bass, a sustained pad, and a sharp lead. Use only the five-step process above. The point isn’t to make something studio-ready — it’s to internalize the workflow.
• If you have access to an FM synth (Operator in Ableton, FM8, Dexed), load a preset and tweak it. Notice how small changes create big shifts. Compare that to tweaking a subtractive patch, where the changes are more gradual and predictable.
• Listen to a track you like and try to identify: is this a subtractive sound? FM? Sample-based? Wavetable? You won’t always be right, and that’s fine — the exercise builds your ear for recognizing different harmonic signatures.

Patches Aren’t Presets

One last thought before we leave the synthesis block. A preset is someone else’s sound — you load it, it works, you move on. A patch is a sound you built (or at least deconstructed and rebuilt). The difference matters because when you understand a patch — when you can trace the signal from oscillator to filter to envelope to output and explain what each stage does — you understand the sound. You can modify it. You can fix it when it doesn’t sit in a mix. You can build something similar from scratch.

The goal of these first six chapters was to give you that understanding. We started with a basic beep — a sine wave, the simplest possible sound — and built outward: added harmonics, added filtering, added envelopes, added modulation, added distortion. Every complex sound in the world is some combination of those elements. When you hear a synth patch in a track and think “I know how that’s built,” that’s the laboratory paying off. And when you get to the effects and mixing chapters, the same building blocks — filters, envelopes, gain, modulation — will be waiting for you.

This primer deals primarily with subtractive synthesis — it’s the most intuitive method and the one that teaches the most transferable concepts. If you want to go deeper into FM, wavetable, granular, and additive synthesis, the Synthesist course covers all of it.