TR Get a Quote

Signal Tone Generator with FFT Spectrum

Hear and see the same signal at once. Two close tones produce a beat, harmonics give a richer sound; use it to get a feel for the concepts met in vibration analysis.

Tone 1
Tone 2
Tone 3

Sound plays only after you press the button. Start low if you use headphones.

Beat frequencies between tones —
RMS
—
Peak
—
Crest factor (peak/RMS)
—

Time waveform

FFT spectrum

These tools are intended for preliminary assessment and training. Decisions on critical equipment should be based on on-site measurement and expert evaluation.

How to use

  1. Enter the frequency and amplitude of each tone; a tone with zero amplitude is off.

  2. Press "Play"; changes are applied to the sound instantly.

  3. Use close tones such as 440 and 443 Hz to hear a beat that swells three times a second.

Theory & formulas

The signal is x(t) = Σ Ai·sin(2πfit). For independent tones the RMS is √(Σ Ai²/2).

A pure sine has a crest factor of √2 ≈ 1.41; impulsive signals (bearing damage) push it higher.

Two close tones beat at |f1 − f2|. The spectrum shows two separate lines; the beat is seen in the waveform.

Frequently asked questions

Why does the sound pulse?

Two close frequencies create a beat. It is the audible version of the "breathing" vibration measured on two machines running at nearly the same speed on one foundation.