tags: mus-305

Ring Modulation

Ring modulation is a form of [modulation synthesis] in which two [signal]s of [frequencies] $f1$ and $f_2$ are multiplied, which results in _sum and difference tones: $f_1+f_2$ and $|f_1-f_2|$.

There are two cases:

1. If $f_1$ and $f_2$ are both [sine waves], then the output [spectrum] consists of two sidebands
2. Otherwise, the output spectrum consists of the sum and difference tones for each [harmonic] in both signals

This results in the following:

• the output spectrum is unrelated to the inputs by [harmonic relationship]
• $f_1$ and $f_2$ do not appear in the resulting spectrum
• each [partial] in $f_1$ produces the sum and difference with all partials in $f_2$, which often results in dense sound

Ring modulation is the [sound synthesis] equivalent of the [Heterodyne principle].

Sources

• MUS 305 Lecture
• MUS 407 The Studio Age: Musique Concrète