Make the most of
Frequency Master.

Sound generator

Choose Steady for a continuous carrier or Modulated to vary its loudness. Select a waveform, enter a carrier frequency in hertz, or move the slider. The slider follows a logarithmic scale so both low and high values are usable. Select .00 for hundredth-hertz precision; hold the arrow buttons to change a number continuously. Press Start sound to hear it and Stop sound or Escape to stop it. Begin at a comfortable volume.

Waveforms change the character of the sound. Sine is the simplest; triangle, square, saw and the other shapes contain different harmonic content. The waveform monitor is a visual sketch of the selected signal.

Amplitude modulation

Turn on Amplitude modulation to make the carrier grow and fade. Modulation rate sets how many loudness cycles occur per second; Depth controls how strong the change is. At 0% the sound stays steady. At 100% the envelope reaches silence. Double modulation adds a second, slower movement to the first envelope; it requires a free account with confirmed email. The rest of the studio works without an account.

Frequency explorer

Choose a segment of the wheel to browse a collection. Its details and presets appear below. Select a playable preset to load and hear it; select it again to stop. Presets are starting points, so you can still adjust the generator. The collection text explains what is measured, what is a convention, and what is only a reference.

Tuning keyboard

Open the music collection to compare the same piano key under different tuning references. Choose Piano or Pure tone, switch the tuning reference, and play a key. The readout shows the selected note and frequency. Set keyboard volume independently from the generator, and expand to the full 88-key range when needed. The 528 reference is an alternative modern reference, not a historical standard.

Sound library

Press a sound to start its loop and press it again to stop. Several sounds can play together, alongside the generator. Each sound has its own volume slider. The library includes generated noises and recordings; recording credits are linked below it. Switching to another browser tab does not intentionally stop playback, but leaving the page does.

Visible spectrum

Choose the light segment, then move the Wavelength slider between violet and red. The panel shows an approximate screen colour, wavelength in nanometres and corresponding frequency in terahertz. This is a visual and numerical reference. Your screen does not emit a precisely selected wavelength, and the sound generator does not produce optical radiation.

Listening games

Find the tone: listen to a hidden sine wave, tune your answer and compare the frequencies. Easy, medium and hard use 10 Hz, 1 Hz and 0.1 Hz steps. Guess the sound: choose a category, play a recording, then pick an answer or type a short name. The games are open without registration.