Ring Modulation (RM) Synthesis is almost identical to AM synthesis with the exception that it uses a bipolar modulation signal. A bipolar signal is simply a signal that has positive and negative values. An audio waveform is an example of a bipolar signal and can in-fact be used for the modulation signal to alter another audio waveform used as the carrier. The use of a bipolar signal causes an interesting difference in the output signal when compared to AM synthesis. When the modulation signal is used to quickly cycle the carrier signal’s amplitude, like AM synthesis it forms two additional sidebands, but the carrier signal is cancelled out and disappears.