Downsampled Equaliser based on approximate brick-wall filtering
Illustrates the use of the Brick-wall 8-band Equaliser in combination with a downsampler. The equaliser
performs equalisation over 8 octave frequency bands. By placing the down-sampler before the equaliser, the frequency
bands of the equaliser are reduced by the down-sampling factor (two in this example). You may use any combination of
down-(or up)-samplers to achieve any desired set of equalisation bands. This illustrates the power and versatility of
WaveWarp's multi-rate audio engine, whereby any component adapts itself to the sample rate of its input signal(s). (You
may momentarily by-pass the down-sampler on this DrawingBoard by connecting the audio file directly to the equaliser. As
you do so, note that the frequency bands of the equaliser automatically adapt to the new sample rate).
Experiment with all settings to explore the behaviour of this versatille combination of components.Try different
down-(or-up)-sample factors.
Note that the Brick-wall 8-band Equaliser block is implemented by approximate brick-wall filtering in the frequency domain
(i.e. by directly weighting the FFT data by the chosen gain values across the frequency range). This simple technique is
highly efficient but introduces spectral distortion and artefacts. However, for many musical purposes, the distortion is not
noticable... or may even be useful when creating special effects!
If, nevertheless, you need to perform accurate equalisation without adding spectral distortion, you can build elaborate
equalisers from WaveWarp's wide range of Digital Filters and Multi-rate components.
