Re: [Audacity-devel] Classic Filters status

[Federico M. <fm...@fc...>]

Steve,

> That makes sense where component count, physical size and
> manufacturing costs of analog filters are relevant, but surely it is a
> spurious trade off for digital filters. Yes a 2nd order Chebyshev
> filter may have a slightly steeper roll-off compared with a second
> order Butterworth, (at the expense of ripple in either the pass band
> or stop band), but for digital filters there is absolutely no need for
> that compromise - if you want a steeper roll-off, use a higher order
> Butterworth filter and then you get a steeper roll-off with no ripple.

Higher order in Butterworth means more phase distortion (as in any 
analog filter), what in turn means worse transient response (for 
instance, more ringing. It ios true that for the same order Chebyshev is 
worse than Butterworth, but a Butterworth of larger order has worse 
transient behavior,

Regards,

Federico