08 Synthesisers

What is the primary function of an oscillator in a synthesiser?

• To create white noise

• To shape the frequency content

• To create an initial sound according to a waveform

• To simulate wind sounds

Answer explanation

The primary function of an oscillator in a synthesiser is to create an initial sound according to a waveform. It generates periodic signals that form the basis of the sound, unlike the other options which do not define this core function.

What does a synthesiser's polyphony indicate?

• The type of waveform used

• The number of notes it can play at once

• The frequency range of the sound

• The amplitude of the sound

Answer explanation

A synthesiser's polyphony indicates the number of notes it can play at once. This is crucial for understanding its capability to create complex sounds and harmonies simultaneously.

What is the purpose of a filter in a synthesiser?

• To create a sweeping effect

• To shape the frequency content of the signal

• To add tuning controls

• To generate white noise

Answer explanation

The purpose of a filter in a synthesiser is to shape the frequency content of the signal, allowing specific frequencies to be emphasized or attenuated, which is essential for sound design.

What does the term "cutoff" refer to in the context of synthesisers?

• The point where the sound is loudest

• The point beyond which frequencies are removed

• The initial sound created by the oscillator

• The number of notes played simultaneously

Answer explanation

In synthesizers, the term "cutoff" refers to the frequency point beyond which certain frequencies are filtered out, shaping the sound. This is crucial for controlling the tonal quality of the output.

What effect does high resonance have on a synthesiser's filter?

• It reduces the amplitude of the sound

• It creates a sweeping effect

• It leads to self-oscillation and creates a pitched note

• It removes high frequencies

Answer explanation

High resonance in a synthesiser's filter causes the filter to amplify certain frequencies to the point of self-oscillation, resulting in a pitched note. This is why the correct answer is that it leads to self-oscillation and creates a pitched note.

What is the primary function of an amplifier in a synthesizer?

• To control the pitch of the signal

• To control the volume of the signal

• To control the filter frequency

• To control the modulation rate

Answer explanation

The primary function of an amplifier in a synthesizer is to control the volume of the signal. It boosts the audio signal's strength, allowing for greater control over the output level.

Which of the following is NOT a stage in an envelope?

• Attack

• Decay

• Sustain

• Modulate

Answer explanation

The stages in an envelope are Attack, Decay, and Sustain. 'Modulate' is not a stage in an envelope, making it the correct answer. It refers to changing parameters over time, not a specific stage.

What does LFO stand for in synthesizers?

• Low Frequency Oscillator

• Linear Frequency Oscillator

• Light Frequency Oscillator

• Loud Frequency Oscillator

Answer explanation

LFO stands for Low Frequency Oscillator, which is used in synthesizers to modulate parameters at low frequencies, creating effects like vibrato and tremolo. The other options do not accurately describe this function.

Which type of synthesis involves combining simple sounds to create a new one?

• Subtractive synthesis

• Additive synthesis

• FM synthesis

• Sample-based synthesis

Answer explanation

Additive synthesis involves combining multiple simple sounds (sine waves) to create complex tones. This method builds new sounds by adding frequencies together, making it distinct from other synthesis types.

In FM synthesis, what is the role of the modulator?

• To filter the sound

• To create a cyclic change in parameters

• To modulate the carrier frequency

• To add harmonics to the sound

Answer explanation

In FM synthesis, the modulator alters the frequency of the carrier wave, creating complex sounds. This modulation is essential for generating the rich timbres characteristic of FM synthesis, making 'To modulate the carrier frequency' the correct choice.