Filter Design Toolbox™

fdesign.octave - Octave filter specification

Syntax

d = fdesign.octave(l)
d = fdesign.octave(l, MASK)
d = fdesign.octave(l, MASK, spec)
d = fdesign.octave(..., Fs)

Description

d = fdesign.octave(l) constructs an octave filter specification object d, with l bands per octave. The default value for l is 1.

d = fdesign.octave(l, MASK) constructs an octave filter specification object d with l bands per octave and MASK specification for the FVTool. The available values for mask are:

• 'class 0'

• 'class 1'

• 'class 2'

d = fdesign.octave(l, MASK, spec) constructs an octave filter specification object d with l bands per octave, MASK specification for the FVTool, and the spec specification string. The specification strings available are:

• 'N, F0'

(not case sensitive), where:

• N is the filter order

• F0 is the center frequency.

The center frequency is typically specified in normalized frequency units, unless a sampling frequency in Hz is included in the specification: d = fdesign.octave(..., Fs). In this case, all frequencies must be specified in Hz, with the center frequency falling between 20 Hz and 20 kHz (the audio range).

Examples

Design an sixth order, octave-band class 0 filter with a center frequency of 1000 Hz and, a sampling frequency of 44.1 kHz.

d = fdesign.octave(1,'Class 0','N,F0',6,1000,44100)
Hd = design(d)
fvtool(Hd)   

The following figure shows the magnitude response plot of the filter. The logarithmic scale for frequency is automatically set by FVTool for the octave filters.

See Also

fdesign

fdesign.nyquist

fdesign.parameq