Synth Flashcards
Oscillator
**Produces the pitch of raw waveforms (sawtooth, sine, etc). with its frequency. **
The oscillator is the main point of interaction between you and the raw sound waves—it’s where the sound is first generated before being shaped by filters, envelopes, and modulation. It’s like the “starting block” of the sound design process.
What do filters do
These sculpt the sound by cutting out certain frequencies. They can make the sound brighter, warmer, or more muffled.
What do envelopes do
As related to a synth’s parameters, controls how the sound evolves over time.
Envelopes shape how a sound evolves over time by controlling parameters like amplitude, filter cutoff, or pitch. The most common type, an ADSR envelope (Attack, Decay, Sustain, Release), determines how a sound starts, fades, holds, and ends.
ADSR Envelope
The envelope adjusts the settings of the synth’s parameters. The ADSR envelop is attack
decay
sustain
release
Attack
Phase of the ASDR envelope for how fast the tone reaches full volume
Decay
Phase of the ADSR envelope. Decay is how long it takes to drop from max volume to the sustain level.
Sustain level is the volume that remains while the key is held—you can think of it as the “default” volume after the initial peak.
Sustain
Phase of the ASDR envelope for the volume/intensity of the note that is maintained while the key is held down.
Sustain level is the volume that remains while the key is held—you can think of it as the “default” volume after the initial peak.
Release
Phase of the ASDR envelope for how long it takes the note to fade out. How long it takes for the sound to fade from the sustain level to zero after you release the key.
Effects
These can add things like reverb, chorus, distortion, or other effects to the sound.
Synth Patch
A recipe for a sound on a synthesizer. Includes oscillators, filters, envelopes, effects.
Why is it called a synth patch
In earlier synthesizers (modular synths), you literally had to patch cables between different modules to create a sound. The term “patch” stuck around even for today’s digital synths where the settings are saved electronically.
Types of synth patches
Presets or user generated patches
Waveform
The visual pattern of the oscillation over time, typically represented as a graph of amplitude (volume) versus time. The shape of the waveform influences the tonal quality (or timbre) of the sound.
Some common types of waveforms
Sine, Sawtooth, Pulse (with variant of Square), Triangle
Sine wave
A smooth, pure tone with no harmonics.
Square wave
A type of pulse wave. A more buzzy, hollow sound with odd harmonics.
Sine wave
A smooth, pure tone with no harmonics.
Sawtooth wave
A rich, bright sound with both odd and even harmonics. Bright and harsh, rough like a saw, kind of ploppy. Represented by a downward triangle-like glyph
Triangle wave
A softer sound, similar to a sine wave but with more harmonic content.
Waveforms: X and Y axis meanings
Time-Varying: Waveforms depict changes over time.
The horizontal axis (x-axis) typically represents time, the distance between peaks representing how fast the pressure changes (frequency).
while the vertical axis (y-axis) represents the strength or value of the wave, how much the pressure changes
Periodic vs. Non-periodic waveforms
Periodic waveforms repeat their pattern at a regular interval. In contrast, non-periodic waveforms, like chirps or pulses, don’t have a repeating pattern.
Why does a square wave sound the way it does?
Square wave: Abrupt transitions between high and low voltage create a buzzy, edgy sound.
Why does a sawtooth wave sound the way it does?
Sawtooth wave: A gradual rise in voltage followed by a sharp drop creates a buzzy, brassy sound.
Why does a triangle wave sound the way it does?
Triangle wave: A ramp up in voltage followed by a ramp down creates a mellower, bell-like sound.
Why does a sine wave sound the way it does?
it is a pure tone with no harmonics, meaning it contains only a single frequency (the fundamental frequency) and no overtones.
Why use multiple oscillators?
These oscillators can be combined in various ways to create richer, fuller sounds. You can have them play the same note (unison) or slightly detuned versions of the same note for a thicker sound. FM synthesis (Frequency Modulation) uses one oscillator to modulate the frequency of another, creating complex and evolving timbres.
Analogy for oscillator vs waveform
Imagine a light dimmer switch. Turning the knob up and down controls the brightness of the light (analogous to pitch), but it doesn’t change the color of the light bulb (analogous to waveform). In an oscillator, the frequency controls how often the signal repeats (brightness), but the shape of that repeating signal (sine, square, etc.) determines the waveform (color).
Pulse waveform
Pulse Wave
A pulse wave’s shape is defined by its pulse width (duty cycle). A square wave (50% pulse width) has a full, balanced sound with strong odd harmonics. Narrower pulse widths produce thinner, buzzier tones due to increased higher harmonics, while wider pulse widths create a fuller, richer sound. Pulse-width modulation (PWM) adds movement by dynamically changing the width.
When to use: Ideal for versatile timbres from buzzy and nasal to full and harmonic-rich. Adjust pulse width if the sound is too thin or harsh.
When to edit the pulse wave
When to use: Ideal for versatile timbres from buzzy and nasal to full and harmonic-rich. Adjust pulse width if the sound is too thin or harsh.
Example: “I don’t want that buzzy sound”
Difference between low-pass filter and cutoff knob
The difference is that a low-pass filter is the actual electronic circuit or processing function that performs the task of filtering frequencies, while the cutoff knob is the control interface that lets you adjust the filter’s cutoff frequency.
The low-pass filter is the “tool” that reduces high frequencies.
The cutoff knob is how you tell the tool where to start cutting.
To control the low-pass filter, you use the cutoff knob
Low pass filter/cutoff knob
Low-Pass Filter
A filter that allows low frequencies to pass through relatively unchanged while reducing (attenuating) the volume of high frequencies above a set cutoff point. Used to create warmer, less bright sounds.
Effect: a “warmer” or “mellower” sound because the high-frequency content, which often contributes to brightness, harshness, or “sizzle,” is reduced. Example: “This sound has too many high frequencies, so if I adjust this knob, the bass and the mid frequencies will stand out more.”
Controlled via:
-Cutoff knob (frequency, filter) knob: determines the point at which the attenuation begins.
-Resonance/Emphasis: This boosts the frequencies around the cutoff point, which can add a “ringing” or emphasized quality to the sound. At high resonance settings, the filter can even self-oscillate, producing a tone of its own.
Slope (or Poles): This determines how steeply the frequencies are attenuated above the cutoff point. A steeper slope results in a more dramatic cut.
What does ADSR envelope apply to?
Parameters of the synth, mainly:
Amplitude (Volume): How the loudness of a sound evolves.
Filter: How the cutoff frequency of a filter changes over time.
Pitch: How the pitch shifts across the attack, decay, sustain, and release phases.
Modulation: Controlling any other effect or parameter dynamically.
Amp envelope attack
AMP ENVELOPE ATTACK
Changes the volume over time in different stages
Attack stage: how long it takes to go from silent to full volume. Setting it to 150 is a common one because it sounds like a stringed instrument. But 0 is most common. You can see the angle of the increase in the visualizer.
Amp envelope release
AMP ENVELOPE RELEASE
The same as Amp Envelope attack in reverse: how long it takes for a note to drop from set volume to zero after you let go.
What’s a normal sounding setting for amp envelope release?
15 is a typical, normal-sounding setting. 0 sounds extremely staccato and abrupt.
What happens if you let go during the amp envelope attack before you get to full volume?
The sound will not reach the full maximum volume because the attack phase is interrupted. Once you release the key, the release phase will start, and the tone will fade out from whatever volume it reached during the attack.
If the decay/release dial seems to have no noticeable effect on the sound or cuts off too suddenly…
…it could mean the release time is set too short or the decay phase isn’t allowing enough time for the sound to transition smoothly.
If the sound is cutting off too quickly or suddenly, adjusting the release time to a slightly longer value should give the sound more time to fade out and avoid a jarring cutoff.
Mix knob
The Mix knob is typically used to blend or balance two or more oscillators/signal sources. In synthesizers and effects processing, this knob adjusts the relative level of different sound elements.
What mixes does a mix knob control
Effect Mix: When using effects like reverb, delay, or distortion, the mix knob allows you to control how much of the dry (unprocessed) signal versus the wet (effected) signal is present.
Oscillator Mix: blend different oscillators, like mixing a saw wave and a square wave together to create a richer sound.
Stereo Mix: controls the balance between left and right channels or the overall stereo width of the signal.
Semi knob
allows you to adjust the pitch of a sound in semitone intervals, making it crucial for both pitch modulation and tuning accuracy.
When you’d adjust a semi knob
You typically use the Semi knob to detune oscillators slightly to create a thicker (chorus-lie) sound, or to transpose
How do you create a chorus-like effect
By slightly detuning two oscillators with the semi knob
How to bring two out-of-tune oscillators into alignment
Use a fine-tune knob, not the Semi knob. Not all synthesizers have a Fine Tune knob, but it’s common on older analog synthesizers and digital synths that aim for a more precise control over pitch. If your synthesizer doesn’t have a Fine Tune knob, you might be able to use other pitch controls like unison mode, modulation, or other fine adjustment settings to achieve a similar effect.
Which knob allows you to transpose?
Semi knob. If the Semi knob is set to +1, the pitch will be one semitone (half-step) higher than the starting pitch.
Which knob is good for layering sounds?
I Also common: 7 semitones=a harmony of a 5th. Just add 7 to the # of semitones in whatever octave you want.
- You can do 50%/50% of each oscillator if you want to clearly hear the two pitches or octaves
- You can do 30%/70% if you want to blend them more
Which semi knob adjustment creates octaves?
12 semitones=one octave (super common) or 24 = 2 octaves or 36=3 octaves.
Why would you create a layered sound with octaves, using the semi knob?
It makes a “taller” sound and adds height.
Which semi knob adjustment creates the harmony of fifths?
7 semitones=a harmony of a 5th. Just add 7 to the # of semitones in whatever octave you want.
What are the two common balances for oscillators as controlled by the semi knob?
- You can do 50%/50% of each oscillator if you want to clearly hear the two pitches or octaves
- You can do 30%/70% if you want to blend them more
The Low Pass Filter (cutoff knob) when set low can make it hard to hear the effect of the Mix knob. Why?
A low cutoff frequency removes high frequencies. If an effect primarily changes high frequencies (like some chorus, distortion, or reverb types), and the filter removes those frequencies, you won’t hear the effect much, even if the Mix knob is set to favor the processed sound. The filter masks the changes the Mix knob is supposed to make, making it hard to “figure out” what the Mix knob is doing.
Why can a thin pulse wave sound similar to a saw wave, and what problem could arise if you don’t know this?
A thin pulse wave sounds like a saw wave because both share similar harmonic content, with the pulse wave’s narrow width emphasizing higher harmonics. If you don’t understand this, you might unintentionally create a sound that lacks the distinct tonal character you need (e.g., thinking a pulse wave will be fuller when it’s actually too thin or sharp, or trying to create a saw-like texture with a pulse that sounds too harsh).
How to make a bass patch
Cutoff: Low or Mid
Amp attack: 0 ms
Amp release: Quick
How to make a lead sound patch
Cutoff: Mid to High
Amp Attack: 0-150 ms
Amp Release: Quick to Medium
How to make a pad patch
Cutoff: Mid
Amp attack: 150 to Long ms
Amp release: Medium to Long
Pad
Filler sounds, good for layering. Like a background swell or chorus sound
Which semi knob settings are best to use, and why?
Stick to octaves and fifths occasionally because it can make it hard to work with other components due to the harmonies it gives you
Filter (general term) and key elements
Allows you to shape the frequency content of a sound to emphasize or suppress specific ranges of sound. Filters can be thought of as ways to “sculpt” the timbre or texture of a sound.
Key Elements:
Cutoff frequency
Resonance (Q)
Slope
Common types of filters
Low pass
High pass
Band pass
Band stop/notch
Reasons to use filters
Tone shaping: Filters are widely used to sculpt the harmonic content of a sound, whether to create warmth, remove harshness, or shape the character of the sound. Example: suppress certain frequency ranges
Movement in sound design: By using a filter envelope, filters can also be used dynamically to change the sound over time. Example: a low-pass filter with a filter envelope can slowly open up a pad sound from muffled to bright, giving the sound a sense of motion or evolution.
Filter Envelope Attack
Controls how quickly the filter opens after a note is played. A slow attack means the filter will gradually allow more high frequencies to come through, while a fast attack will immediately open the filter and allow the full sound spectrum to pass through quickly.
What does the Cutoff knob do in the Filter Envelope?
Sets the base frequency for the filter, determining how much high frequency (brightness) passes through. The filter envelope modulates the cutoff point over time.
What does the Filter Envelope Amount (Env) knob do?
Controls how much the envelope modulates the cutoff frequency. It determines the depth or range of the cutoff’s movement based on the envelope’s shape (ADSR).
IOW, the cutoff knob sets the initial starting point of the filter’s frequency (its static base), and the Env knob moves it by a certain amount based on the envelope’s shape (ADSR).
What is the filter envelope?
Modulates the CUTOFF frequency over time, affecting the sound’s brightness (high frequencies).
Reminder: the Cutoff knob modulates the brightness.
Where does the Filter Envelope start at?
At the frequency set by the Cutoff knob.
Where does the filter envelope end?
At the point determined by the Envelope Amount knob (the strength of the modulation).
What knobs does the Filter Envelope use?
1) Cutoff knob: Sets the starting frequency (base cutoff point) for the filter.
2) Envelope (Env) knob: Controls how much the envelope modulates the cutoff frequency, affecting the depth of the modulation. It’s like a dial for the strength of the envelope’s ADSR effect.
What does the cutoff knob cut off?
It sets the frequency point where a filter attenuates (reduces) certain frequencies. Examples:
-In a Low-pass filter (LPF): Frequencies above the cutoff are cut off.
-In a High-pass filter (HPF): Frequencies below the cutoff are cut off.
How to create a sound that starts muddy and gets very bright?
Cutoff: Set low (e.g., 0 Hz).
Env Amount: Set high (e.g., 800 Hz).
Result: A low, muddy sound that becomes bright over time as the envelope modulates the cutoff upwards.
How to create a sound that starts moderately bright and brightens slightly?
Cutoff: Set moderate (e.g., 400 Hz).
Env Amount: Set low (e.g., 150–200 Hz).
A moderately bright sound that only slightly increases in brightness.
What does “strength of modulation” mean in relation to the cutoff frequency?
Refers to how much the cutoff can move from its initial position based on the envelope’s influence.
Strong modulation: Large range of movement, dramatic change in timbre.
Weak modulation: Smaller range, subtle change in sound.
How does envelope modulation affect timbre?
Envelope modulation creates dynamic changes in timbre by modulating the filter’s cutoff over time. This causes the sound’s brightness, darkness, and overall tonal quality to evolve during the note’s duration.
When you encounter “modulation,” always think of how envelope stages (ADSR) control dynamic shifts in sound, such as changes in filter cutoff, not just a global “change” in timbre.
How are timbre and ASDR settings/stages related?
Timbre refers specifically to the character or quality of the sound — aspects like brightness, warmth, and texture. It’s how you can tell the difference between a clarinet and a flute just by listening. So, the ASDR settings don’t create timbre, but they modulates aspects of it, like filter cutoff or amplitude, which then affect the perceived timbre over time.
When you encounter “modulation,” always think of how envelope stages (ADSR) control dynamic shifts in sound, such as changes in filter cutoff, not just a global “change” in timbre.
What does the Filter Envelope’s “Env” knob do?
It adds a range of brightness onto whatever the cutoff knob is set to. It is NOT a fixed point of brightness.
What happens if Sustain is set to zero in the ASDR Envelope?
If sustain is set to zero, then decay and release both go to silence, but for different reasons:
Decay happens while the key is held, dropping to the sustain level.
Release happens after the key is let go, fading to silence.
