Hey Everyone, Can someone explain to me the natural of amplitude modulation in regards to sound. As in one modulator frequencies' amplitude modulating the amplitude of a carrier frequency. Because at low frequencies the modulator only affects the carrier in a way that makes its volume go up and down like tremolo (0.5hz). But at higher speeds like when the carrier is being modulated at 65hz the carrier starts to produce new frequencies known as sum and difference. Why? What is the nature of this process that makes it happen? Why do you start to hear new frequencies just by turning the volume up and down of a signal at super high speeds?