I wasn't really sure what the difference was either.

I found that the following Wikipedia article explained it enough for me:

http://en.wikipedia.org/wiki/Butterworth_filter
Butterworth filter - Wikipedia, the free encyclopedia

This article is geared more towards the electrical engineering crowd (it has
circuit diagrams), but the concepts seem to be clear enough on how they
apply to musical signals as well.

You won't find answers to all Csound-related terminology at Wikipedia but
you may find many of them :)

Anthony Kozar
anthonykozar AT sbcglobal DOT net


S. Massy wrote on 2/11/06 3:52 AM:

> While I know what a low-pass
> filter is, I'm afraid that what a "second order Butterworth" lp filter
> is and how it differs from other lp filters is beyond me. Is there any
> extensive online resource such as a glossary where such information
> might be readily available?

Anthony Kozar wrote:
> I wasn't really sure what the difference was either.
> 
> I found that the following Wikipedia article explained it enough for me:

It's true, that while the manual can be terse in many respects,
pasting an offending term into a Google text box will always 
yield a portal to more information than you might care to know
about the subject.

Toby