Filters

[Magnus Danielson]

>>>>> "BS" == Ben Stuyts <ben at stuyts.nl> writes:

 BS> On Fri, 08 Jan 1999, James Jackson wrote:
 >> Ahh, I am designing my filters on a DSP chip, so it might be possible to
 >> take it to zero. Thanks alot.

 BS> That is interesting. What kind of filter are you designing? I'm interested in  
 BS> the topology, and what kind of effect it has. Will it have the usual cut-off  
 BS> and resonance controls?

 BS> Are you trying to get something similar to an existing analog filter?

The benefit with digital IIR filters is that 0 Hz is as achievable as
1 kHz. An integrator for instance can be perfect as long as it does
not saturate (it will wrap). An analog filter will would suffer the
leakage of the capacitor and surrounding curcuit to be anyway near 0
Hz, but it may get efficiently near 0 Hz seen from a audio
perspective.

These filters are fairly simple to acheive, a few multiplies and a few
additions. The calculations are a bit worse, but they are managable.

Cheers,
Magnus