zen4 labs

iOS and SoC specialists for teaching & research

header photo

FourierSynth - new version available on the AppStore for iPad & iPhone

The Fourier Synthesiser allows students, engineers and musicians to study quantitatively the Fourier components of periodic waveforms. Real-time superposition of harmonically related sinusoids upto 15th harmonic can be viewed with the built in Time Domain display or alternatively viewed on an Oscilloscope connected to the audio stereo output. Those musically inclined can choose to listen to any two sinusoids or the sum of all selected sinusoids.

Designed for undergraduate teaching in the Department of Electrical Engineering & Electronics at The University of Liverpool.


  • Select Sine and Cosine from fundamental to the 99th harmonic

    see how convergence to the ideal improves with more components
  • Fundamental frequency adjustable from 50Hz to 1kHz - coming soon
  • Individually control amplitude and On/Off state of each harmonic
  • DC term available on iPad, iPhone display
  • Select from a range of 10 preset waveforms

    Square, Triangle, Sawtooth, Amplitude Modulation, Impulse, Half and Full Wave Rectification
  • Use the full range of Swipe, Tap, Pinch, Press & Hold Gestures

  • Tap harmonic component to toggle On or Off
  • Scroll up or down to set amplitude of each harmonic component
  • Swipe left/right to undo/redo
  • Tap Coefficient Button to change to Sine or Cosine
  • Tap 'Coefficient Button' for keyboard input
  • Long Press anywhere to 'unlock' coefficient
  • ​Long Press any coefficient to lock
  • ​Long Press + Drag selects and locks highlighted coefficient
    left/right - coarse, up/down - fine


  • Tap Time Domain display to toggle channel 1 On or Off
  • Scroll (pan) left/right - X shift (horizontal position)
  • Scroll (pan) up/down - Y Shift (vertical position)
  • ​Long Press + Drag left/right to change Timebase
  • ​Long Press + drag up/down to change Y gain



History - The Original Fourier Synthesiser used at The University of Liverpool - Dept of Elec Eng & Electronics

Designed by the same Engineer 30 years earlier