In article ,
JohnT wrote:
Thanks for the comments.
What I am trying to do is to optimise a voice signal in the presence
of high background noise levels, so I need a fairly sharp bandpass
filter.
I have of course tried simple RC sections for HPF and LPF but this is
not sufficiently sharp for the purpose.

Better way might be to use a noise cancelling mic.

--
*I almost had a psychic girlfriend but she left me before we met *

Dave Plowman London SW
To e-mail, change noise into sound.