Amplitude Modulation (AM) Synthesizer

An amplitude modulation synthesizer uses the principle of amplitude modulation to generate sound. Using amplitude modulation, two signals—a carrier signal and a modulating signal—are combined to create a new signal with elements of both the carrier and modulating signals’ frequencies.

The modulating signal is typically a more complex waveform with variable amplitude, whereas the carrier signal is usually a sine wave or other simple waveform with a fixed frequency. The modulating signal’s amplitude is used to modify the carrier signal’s amplitude, which alters the final signal’s overall loudness.

AM synthesis can produce various sounds, from subtle timbral variations to intricate, evolving textures. It is frequently used in electronic music and sound design to create sounds that are challenging to achieve with conventional subtractive synthesis or are not possible.

To control the amplitude of the carrier signal, an LFO (low-frequency oscillator) is frequently used as the modulating signal in AM synthesis. Although this is a straightforward application of AM synthesis, there are numerous other ways to create and modify the modulating signal to create various sounds.

There are countless ways to use AM synthesis, one of which is using a different sound source as the modulating signal.

The key is that the modulating signal’s amplitude controls the carrier signal’s amplitude, which changes the overall loudness of the resultant signal and produces a different sound.

Examples

1. Csound: Csound is an open-source software synthesizer that uses additive synthesis to generate a wide range of sounds. It is widely used in academic and research settings and by electronic music composers and sound designers.
2. Serum: Serum is a popular commercial software synthesizer that uses additive synthesis to create complex, detailed sounds. It is known for its high-quality sound and user-friendly interface.
3. Reaktor: Reaktor is a software synthesizer and modular synth platform by Native Instruments. It allows users to create their own additive synthesizer using the software’s building blocks.
4. Waldorf Blofeld: The Waldorf Blofeld is a hardware synthesizer that uses additive synthesis to create a wide range of sounds. It is known for its high-quality sound and ability to create complex, evolving textures.
5. Yamaha FS1R: The Yamaha FS1R is a hardware synthesizer that uses additive synthesis to create a wide range of sounds. It is known for its unique formant synthesis, which allows for creating vocal-like sounds.