FM Spectrum

The frequencies present in an FM spectrum are $f_c \pm kf_m$, where $k$ is an integer greater than zero (the carrier frequency component is at $k=0$).

Figure 13: Spectrum of a simple FM instrument, where $f_c = 220$, $f_m = 110$, and $I = 2$.

Figure 14: Spectrum of a simple FM instrument, where $f_c = 900$, $f_m = 600$, and $I = 2$.