This demo shows the interesting situation that occurs when we have two sinusoidal signals of slightly different frequencies.

This demo gives the mathematical derivation of how instrument sounds can be synthesized using the principles of frequency modulation. The example sounds include a bell and a clarinet.

This MATLAB demo reconstructs a square, triangle, or sawtooth waveform, using a given number of Fourier Series coefficients.

Here are four movies showing rotating phasors and how the real part of the phasor traces out a sinusoid versus time. Two of the movies show how rotating phasors of different frequencies interact to produce complicated waveforms such as beat signals.

This demo illustrates the connection between a variety of sounds and their spectrograms. Among the different sounds are:

• Simple Sounds
• Chirp Sounds: Synthesized & Real
• Real Sounds
• Wideband Frequency Modulation (FM)

This demonstrates the idea of harmonic sinusoids. Five sinusoids with a common fundamental frequency are added together, one at a time.