Tremolo, vibrato and autopan: what each one moves, and how to use them
Tremolo moves the volume, vibrato moves the pitch, and autopan moves the sound between the speakers. Here is how each works, why tremolo and vibrato get mixed up, and how to set the rate and depth.
Tremolo, vibrato and autopan all use an LFO, a slow oscillator that moves a setting up and down over and over. The difference is what it moves. Tremolo moves the volume. Vibrato moves the pitch. Autopan moves the sound between the left and right speakers.
Tremolo: the volume moves
Tremolo is a regular variation in volume. In an analog synth it is an amplifier controlled by an LFO; in a pedal or plugin the main controls are depth, sometimes called intensity, and speed, and some let you pick the LFO's waveform. A sine gives a smooth pulse; a square switches between two levels, and at full depth chops the sound on and off. Electronic tremolo was built into many early guitar amplifiers.
Vibrato: the pitch moves
Vibrato is a regular, pulsating change of pitch. It adds expression to vocal and instrumental music, and it is usually small: for solo singers, usually less than a semitone either side of the note, and for wind and bowed instruments, less than half a semitone. On a synth, vibrato is an LFO on pitch, which can be brought in with the mod wheel or key pressure so you add it only where you want it.
Bringing vibrato in gradually lets each note settle first. In Kiln, an LFO's FADE sets how long it takes to reach full depth after each note starts, so vibrato blooms on held notes.
Why tremolo and vibrato get mixed up
Fender labeled the tremolo circuit on some of its amplifiers "Vibrato", while the "tremolo arm" on its guitars bends the pitch, which is vibrato. In classical music, tremolo also means something else: a fast repetition of the same note. In production, the usual meaning holds: tremolo is volume, vibrato is pitch.
Autopan: the sound moves between the speakers
An autopanner moves a sound's position in the stereo field with an LFO, so it sweeps from left to right and back. Ableton Live's Auto Pan-Tremolo shows how close the two effects are: in Panning mode two LFOs move the stereo position, and in Tremolo mode a single LFO moves the level. Check an autopan in mono. On a mono source, one side gets louder as the other gets quieter, so the sum stays nearly level and the sweep mostly disappears; with a constant-power pan law you may hear a gentle pulse instead.
Setting rate and depth
- Rate in note values (1/4, 1/8, 1/16) locks the movement to the beat: good for rhythmic tremolo and autopan.
- Rate in Hz runs free: good for a natural vibrato that should not lock to the grid.
- Depth sets how far it moves. Start low and raise it until you hear it, then back off a little.
To turn a tempo into an LFO rate in hertz, use the delay calculator. For how LFOs work on any setting, see what an LFO is.
Tremolo, vibrato and autopan in Kiln
Kiln Synthesizer has four LFOs, each with Sync to follow your DAW's tempo and a FADE that brings it in gradually after each note starts. In the modulation matrix, route one LFO to the Level of each oscillator you are using for tremolo, to each one's Pitch for vibrato, or to each one's Pan for autopan. The Kiln manual lists every source and target.
Questions
What is the difference between tremolo and vibrato?
Tremolo varies the volume; vibrato varies the pitch.
Is a tremolo arm tremolo?
No. A guitar's tremolo arm bends the pitch, so the effect it makes is vibrato.
Does autopan work in mono?
Mostly not. Summed to mono, the left and right movements add back together, so the sweep largely disappears. Check any autopan in mono before you commit.
