Signal processing, made visual.

Fourier series

A repeating wave is a sum of sinusoids.

New here · the first lesson

See what a signal really is, with five small examples you can drag, toggle and step through yourself.

From the library

Four more, drawing themselves as you read.

Filters

A moving average slides along the signal and smooths the noise out.

Systems

Slide a response across the input. The output is the area where they overlap.

The DFT

A tone that fits the window exactly is one line. Any other tone spills into its neighbours.

Converters

A converter rounds the wave to steps. More bits, finer steps.

The library

Eleven parts, each building on the one before.