Hi Alexandre, thanks for your reply.

On 30/01/15 02:39, Alexandre Torres Porres wrote:
it's how the filters were designed, they're not perfect throughout the spectrum

Probably it would be better then to warn users about this limit of ~12 kHz in the help-files then.

you'll need to use/build other filters for that purpose of working with that higher portion of the spectrum (in which I can hardly still hear, by the way)/

Hmm, I can clearly hear the difference between feeding a high frequency to [vcf~] and to [bp~] using a large enough Q (~100 for instance). With that Q, try sweeping from 12kHz until 14kHz in both filters, and you'll hear that [vcf~] behaves as expected, while [bp~] does not change the frequency but only affects the amplitude of the output for some reason.

a few of patches of mine that describe the behaviour of vanilla and some extended filters

Thanks a lot for the patches, but I am actually aware of [vcf~] and [biquad~]. This message of mine was intended to be a bug report rather than a cry for help as I have no particular problem with filters needing a solution right now. But in any case I will check your patches, as I know (and enjoy very much) yours Computer Music With Examples In Pd.

Take care,
Gilberto Agostinho