Octave Band Frequency Calculator
Calculate the upper and lower band edges of an octave or fractional-octave band from the centre frequency: f_upper = f_centre * 2^(1/(2N)), f_lower = f_centre / 2^(1/(2N)).
Lower Band Edge
707.1068 Hz
Lower Band Edge vs Centre Frequency
सूत्र
## Octave and Fractional-Octave Bands Sound analysis often divides the spectrum into bands of constant percentage bandwidth. ### Formulas **f_upper = f_c * 2^(1/(2N))** **f_lower = f_c / 2^(1/(2N))** where N is the fraction denominator (1 for full octave, 3 for third-octave). For a full octave band (N=1): f_upper/f_lower = 2 (one octave). For third-octave (N=3): the ratio is 2^(1/3) = 1.26.
हल किया गया उदाहरण
1000 Hz full octave band.
- 01f_upper = 1000 * 2^(1/2) = 1000 * 1.4142 = 1414.2 Hz
- 02f_lower = 1000 / 2^(1/2) = 1000 / 1.4142 = 707.1 Hz
- 03Bandwidth = 1414.2 - 707.1 = 707.1 Hz
अक्सर पूछे जाने वाले प्रश्न
Why use octave bands instead of equal-width bands?
Our hearing perceives pitch logarithmically. Octave bands have constant percentage bandwidth, matching how we hear. Each band sounds equally wide.
What are the standard octave band centre frequencies?
31.5, 63, 125, 250, 500, 1000, 2000, 4000, 8000, and 16000 Hz. These are preferred frequencies defined in ISO standards.
Why are third-octave bands used?
They provide finer frequency resolution while maintaining the constant-percentage-bandwidth advantage. They are standard for building acoustics and noise regulations.
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