About

Precise frequency management separates amateur mixes from professional productions. Audio engineers use frequency data to identify resonant peaks that cause muddiness or masking in a track. This tool maps musical notes to their exact Hertz values and physical wavelengths based on the standard twelve-tone equal temperament system. It serves as a verification layer for synthesizer programming and room acoustic treatment where standing waves correspond to specific note wavelengths.

The interactive system below goes beyond static reference sheets. It integrates a Web Audio oscillator to provide aural reference for ear training. The harmonic series visualizer aids in additive synthesis by identifying the integer multiples of a fundamental frequency. A built-in chromatic tuner analyzes incoming audio signals to match real-world sounds against the mathematical grid. This utility ensures that tuning discrepancies and phase alignment issues are resolved before the recording stage begins.

Formulas

The frequency of a note is calculated relative to a reference pitch (usually A4) using the twelfth root of two. This defines the logarithmic scale of equal temperament.

f_n = f₀ × (a)ⁿ

Where:

f_n is the frequency of the target note.
f₀ is the reference frequency (standard 440 Hz).
n is the number of semitones away from the reference note.
a is the constant 1.059463 defined as:

a = 2¹¹²

To determine the wavelength of a sound wave in air at 20°C:

λ = vf

Where v is the speed of sound (≈ 343 m/s).

Reference Data

Note	Frequency (Hz)	Wavelength (m)	Wavelength (ft)
C0	16.35	21.09	69.19
A0	27.50	12.54	41.14
C1	32.70	10.54	34.60
A1	55.00	6.27	20.57
C2	65.41	5.27	17.30
A2	110.00	3.14	10.29
C3 (Middle C)	130.81	2.64	8.65
A3	220.00	1.57	5.14
C4	261.63	1.32	4.32
A4 (Concert)	440.00	0.78	2.57
C5	523.25	0.66	2.16
A5	880.00	0.39	1.29
C6	1046.50	0.33	1.08
A6	1760.00	0.20	0.64
C7	2093.00	0.16	0.54
A7	3520.00	0.10	0.32
C8	4186.01	0.08	0.27
A8	7040.00	0.05	0.16

Frequently Asked Questions

ISO 16 standardizes A4 at 440 Hz to ensure consistency across orchestras and electronic instruments worldwide. Before 1955 pitch standards varied significantly between regions and eras. Some modern producers experiment with 432 Hz for aesthetic reasons but 440 Hz remains the global tuning standard for manufacturing and software.

The harmonic series consists of the fundamental frequency multiplied by integers (2f, 3f, 4f). In sound design these overtones determine the timbre or texture of a sound. A pure sine wave has no harmonics while a sawtooth wave contains all integer harmonics. Understanding this series helps you filter or boost specific frequencies to alter the character of an instrument.

Room modes are standing waves that occur when sound waves reflect off parallel walls and reinforce each other. If a room dimension matches half a wavelength of a specific note that note will resonate louder or disappear at certain spots in the room. Knowing the physical length of a frequency helps acoustic engineers place bass traps effectively.

Physics dictates an inverse relationship between frequency and wavelength. Lower frequencies oscillate more slowly and traverse more distance per cycle. A 20 Hz wave is approximately 17 meters long. This requires significant physical space or dense material to absorb which is why treating bass frequencies in small studios is difficult.

Temperature changes the speed of sound in air which affects the resonance of wind instruments. As air gets warmer sound travels faster and wind instruments tend to go sharp. String instruments react differently as the physical expansion of the string material due to heat often causes them to go flat.