I just wrote eight filter objects based on [filtercoeff.mmb~] and [biquad.mmb~] abstractions by Mike Moser-Booth.
Binaries for OS X and Linux are included along with the source code.
The help patches use [spectrum.mmb~] abstraction, also by Mike Moser-Booth, as [filtercoeff.mmb~]'s help patch uses it too.
You can get them here (look for the Various filters link).
Any comments are welcome.