Ring modulation multiplies two signals, the carrier and the modulator, to create two new frequencies: the sum and the difference of the input frequencies.
For example, with a 400 Hz carrier and a 100 Hz modulator, the output contains two sidebands:
- 400 + 100 = 500 Hz
- 400 – 100 = 300 Hz
Both the original carrier and the original modulator are suppressed, so you hear only the new sidebands. This is what separates ring modulation from amplitude modulation, where the modulator is unipolar and the carrier stays in the output alongside the sidebands.
