On Aug 9, 11:48=A0am, Bobby Joe
>
> I guess you can simulate such filters with a DSP, and
> listen to the audio result while playing with the parameters.
LTSpice can read and write wave files. Every time I've tried to do both in the same run it went way too slow or may have but others may have better luck. This would let you do it with the intended circuit design.
A program called "arts builder" lets you define filters and all sorts of other audio stuff on a PC, "wire it up" and send it out the speakers to hear it.