TeslaQuake · Signal Lab

369 SIMULATOR

Three digital-root frequencies, drawn as they actually interfere. Transpose all three together and watch the 3 · 6 · 9 pattern survive every shift.

View
SYNTHETIC
Tiny phone speakers buzz on deep tones — this lifts anything under 150 Hz up an octave so it stays clean. On headphones, a real speaker or a shaker, leave it off.
🎹 Master Transpose 0 st
Speed 1.00× Glow 14
Current 369 Chord
3
174 Hz
DR 3
6
285 Hz
DR 6
9
396 Hz
DR 9
SUM 855 HZ  →  ROOT 9
Presets
Manual Adjust

Locked. Use the master slider to transpose all three together — the digital-root pattern is preserved at every step.

3+6+9 Sum
855 Hz
Sum Root
9
3×6×9 Product
19,591,380
Product Root
9
What you’re looking at

STACK draws each frequency on its own baseline so you can compare cycle counts directly. INTERFERENCE adds them into one summed wave — the shape you’d actually hear. HARMONOGRAPH plots the three against each other on an X/Y plane, the way a Victorian pendulum harmonograph did; simple whole-number ratios close into a stable figure, and anything off-ratio drifts. RADIAL wraps the summed wave around a circle so the periodicity becomes a rosette.

The arithmetic is the honest part: add any of these frequencies’ digits repeatedly and you land on 3, 6 or 9. Transposing by semitones changes the pitch but preserves the ratios between the three, so the pattern holds. That’s a property of base-ten arithmetic — modulo 9 — and not a property of sound.

With audio on, the drawing switches from a synthetic model to the real output of the browser’s analyser node. The chip at the top-right of the panel tells you which one you’re seeing.

All repeated acts or operations I performed had to be divisible by three, and if I missed I felt impelled to do it all over again, even if it took hours.

— Nikola Tesla · My Inventions, 1919

His own published words. The widely circulated line about “the magnificence of the 3, 6 and 9” appears nowhere in Tesla’s writings, letters, patents or contemporary interviews, so it isn’t on this page.

Audio visualisation tool. Not a medical device and no health claims are made. Start at low volume — square and sawtooth content at high level can be harsh.

Common questions

What is a harmonograph?
A Victorian drawing machine that hangs pens from pendulums swinging at different rates. When the rates form simple whole-number ratios the pen traces a stable closed figure; when they drift off-ratio the figure opens up and never repeats. The HARMONOGRAPH view reproduces that behaviour mathematically from the three frequencies you have set.
What is the difference between the STACK and INTERFERENCE views?
STACK draws each frequency on its own baseline so you can count cycles and compare them directly. INTERFERENCE adds all three into a single summed wave — the shape you would actually hear — with the individual components ghosted behind it.
What does the master transpose do?
It shifts all three frequencies by the same number of semitones, so their ratios to each other are preserved. The pitch changes but the relationship does not, which is why the display keeps landing back on the same digital-root family.
Why does it say SYNTHETIC instead of ANALYSER?
With audio off, the page draws a mathematical model of the waves. Turn the chord on and it switches to reading the real output of the browser’s Web Audio analyser node. The chip in the top-right of the panel always tells you which one you are looking at.
Why do some frequencies show an out-of-range warning?
Human hearing runs roughly 20 Hz to 20 kHz. Transposing far down or entering a very low value can push a frequency below that floor, where your speakers will not reproduce it. The wave is still drawn so you can study it, but you will hear nothing.