Introducing the Square Wave
The ideal square wave is a periodic waveform made of instantaneous transitions between two levels. Perfect square waves can only be imagined, since no real-world system has the infinite bandwidth required to produce instantaneous transitions.
Frequency-wise, the ideal square consists of a sine wave of the same frequency (e.g. 100Hz) and all the odd harmonics
to infinity (300Hz, 500Hz, 700Hz, ...) at decreasing levels.
Generating an square waveform in the digital "sampled" world is not as easy as it seems. Samples jumping from one level to the other will do the trick, but only poorly: frequencies higher than half the sampling rate will fold back into the audible spectrum, generating what is known as aliasing. Complex algorithms are needed to trade off sharp edges in the time domain with spectral purity. Our algorithm has been designed to deliver the purest tone instead of the best looking waveform.
The square wave compared to...
Listen to how the square wave sounds in comparison to other classic waveforms such as the sine
. Try to isolate the fundamental frequency by ear (it sounds equivalent to the sine tone) from its harmonics. Our default values are used here (1000Hz, 3s, -3dBFS).