Why A4 = 432 Hz?
What it means
Every musical note has a frequency. A4 is the A above middle C, and it is the reference note that all the other notes are tuned from. Today most music uses A4 = 440 Hz. Inner Dive uses A4 = 432 Hz, which is 8 Hz lower.
A short history
For centuries there was no single standard, and A4 varied from city to city, roughly between 400 and 460 Hz. In 1884, the composer Giuseppe Verdi supported A4 = 432 Hz for the Italian orchestras. In 1939, an international conference in London chose 440 Hz, and in 1955 it became the ISO standard.
What people feel
Many musicians and listeners describe music at 432 Hz as warmer, softer and more relaxing. The sound feels rounder and less tense, which makes it a natural choice for meditation and rest.
The numbers behind it
- 432 is linked to the scientific tuning C = 256 Hz, which follows the powers of 2 (2, 4, 8, 16… 256).
- In this tuning, every C is a whole number: 8, 16, 32, 64, 128, 256 Hz.
- The digits of 432 add up to 9 (4 + 3 + 2), a number many traditions see as complete.
The harmonic series
When a note plays, it also sounds higher tones called harmonics: 2×, 3×, 4× the main frequency, and so on. They give every sound its colour.
432 Hz always returns to 9
Add the digits of each harmonic until one digit is left:
| Harmonic | 432 Hz | Sum | 440 Hz | Sum |
|---|---|---|---|---|
| 1× | 432 | 9 | 440 | 8 |
| 2× | 864 | 18 → 9 | 880 | 16 → 7 |
| 3× | 1296 | 18 → 9 | 1320 | 6 |
| 4× | 1728 | 18 → 9 | 1760 | 14 → 5 |
| 5× | 2160 | 9 | 2200 | 4 |
| 6× | 2592 | 18 → 9 | 2640 | 12 → 3 |
| 7× | 3024 | 9 | 3080 | 11 → 2 |
| 8× | 3456 | 18 → 9 | 3520 | 10 → 1 |
| 9× | 3888 | 27 → 9 | 3960 | 18 → 9 |
Every harmonic of 432 Hz returns to 9. The octaves below do too: 216, 108, 54, 27 all give 9.
440 Hz follows another path
Its harmonics count down: 8, 7, 6, 5, 4, 3, 2, 1, 9, and then the cycle starts again.
How to listen
- Use headphones or speakers.
- Keep the volume low.
- Compare the same piece at 440 Hz and at 432 Hz.
- Notice how you feel with each one.
How Inner Dive uses it
Everything in Inner Dive is tuned to A4 = 432 Hz: pure tones, binaural beats, isochronic tones, instruments and the synth. You can retune it at any time in the settings.