Octave band

Analyzing a source on a frequency by frequency basis is possible but time consuming. The whole frequency range is divided into set of frequencies called bands. Each band covers a specific range of frequencies. For this reason, a scale of octave bands and one-third octave bands has been developed. A frequency is said to be an octave in width when the upper band frequency is twice the lower band frequency. A one-third octave band is defined as a frequency band whose upper band-edge frequency (f2) is the lower band frequency (f1) times the cube root of two.

Calculation

MATLAB

%% Octave Bands
fcentre = 10^3 * (2 .^ [-6:4])
fd = 2^(1/2);
fupper = fcentre * fd
flower = fcentre / fd

%% Third Octave Bands
fcentre  = 10^3 * (2 .^ ([-18:13]/3))
fd = 2^(1/6);
fupper = fcentre * fd
flower = fcentre / fd