Octave band

If it is required to analyse a source on frequency by frequency basis, it is possible but impractical and 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 = (10.0^3) * ((2.0) .^ [-6:4])
fd = (2^0.5);
fupper = fcentre ./ fd
flower = fcentre ./ fd

%% Third Octave Bands
fcentre  = (10.0^3) * ((2.0) .^ ([-18:13]./3))
fd = (2^(1/6));
fupper = fcentre .* fd
flower = fcentre ./ fd