Mark Altin wrote:
> 
> Hi everyone,
> I've recently trying to understand FIR ad IIR filters.  I think I have got it pretty much under my hat, but I just want to make certain of a few things.
> 
> (1) What exactly is the difference between impulse response and frequency response?

In non-precise terms, Impulse response is the sound waveform you get out
for the filter, by sending an input that  is just a single
infinitely-narrow spike. So impulse response is a time-domain waveform.
You could almost think of clapping your hands in a concert hall and
recording the reverberations (although this isn't really exact, since a
hand clap isn't an ideal impulse).

The frequency response of the filter is the fourier transform of the
impulse response. It is the same response, but expressed as a frequency
spectrum of the impulse response.
  

 
> (2) Is the equation for calculating coefficients only needed to create Fc other than SR/4?
> 

I don't understand the question.Sorry. What is the context?
 
> Well Thanks for your time.  I really appreciate it.  Teaching yourself some of this stuff can be quite frustrating sometimes.
> 
> Mark

Even those of use who went to four or more years of engineering school
don't neccesarily completely understand it :-)

--  Larry Troxler --  lt@westnet.com  --  Patterson, NY USA  --