Hallo Frank!
In general this should not matter (although there can be numerical unstabilities with some structures - but I thing that's no problem in your case).
See for example "series and parallel transfer functions" in "INTRODUCTION TO DIGITAL FILTERS" (which is BTW a very nice book): http://www.dsprelated.com/dspbooks/filters/Series_Parallel_Transfer_Function...
LG Georg
Frank Barknecht schrieb:
Hallo,
hm, I'm a bit confused how to place elementary filters: In the book, Miller writes that the r/czero should be placed before the poles and the screenshots also show this: http://crca.ucsd.edu/~msp/techniques/latest/book-html/node160.html
However the example patches (H11 ff.) and the butterworth abstractions that come with Pd have it the other way around and follow the alphabetic order with *z*ero last!
Ciao