:::How about using MLS (maximum length sequence)? ::: :::BTW, there's a nice program for Atari Falcon that does this (and many :::other things). It's called NFMP. You get the impulse respone of anything :::very easy. MLS is used for a couple of things... What is the specific function here? What do you mean by "get the impulse respone of anything very easy" ? m.c.