File README_VCF of Package ladspa
vcf.so and vcf_cv_in.so implement plugins for audio EQ biquad filters
based on the cookbook formulae by Robert Bristow-Johnson:
vcf.so has audio rate ports for signal i/o.
vcf_cv_in.so has additional audio rate inputs for time dependent control of
filter parameters. The Frequency Input is linear between 0..1, where 1
corresponds to 20000 Hz. The input signal is added to the Frequency Offset
Updates are available from http://www.suse.de/~mana/ladspa.html