to make a notch filter do i just pin together a lowpass and a highpass filter with the same cutoff frequency? that's the only way i can think of, but i'm assuming that there is a better way.

also, i remember about a year ago or so, there was a post on the mailing list about someone who had made a 'swiss army knife' filter, ie one that could do lowpass, bandpass, notch, highpass...etc just by switching messages.

anyone know of something like that?

any info on other useful filters would also be welcome.

substract from original signal a vcf~ filter ?

HK

I do the same:
send a signal to vcf~ (setting a specified frequency and high Q)
then subtract from original signal.
It could be used the complex filters as well, but they are quite obscure to me

you can also invert a bp~ and mix it in with the original signal.

here s a stop-band (notch) filter as suggested by Miller in his book.

http://www.pdpatchrepo.info/hurleur/stop-band~.pd

wicked, cheers. can't even remember what this was for...probably making an EQ if i recall vaguely correctly.

am now feeling a wee bit embarrassed that i have not even looked at miller's book yet. i guess i will now.

If you want a static notch there is a [notch] helper that gives the right numbers for [biquad~]

BTW, what's the deal with biquad~? What are the advantages/disadvantages of using biquad~ for a notch filter as opposed to a cpole~>czero~ peaking filter?