Re: [Audacity-devel] Classic Filters status

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

Dear all,

I think this page is enough stuff for a start:

> http://manual.audacityteam.org/man/Classic_Filters 

especially since it has links to wikipedia. It is true that these links 
do not provide insight to applications, but if the effect is working 
successfully and the documentation explains all the available 
parameters, users can start to play about with it.

There are a few things that I note and could be improved.

First, the input parameters differ between Butterworth and both 
Chebyshev's, but only the Butterworth case is depicted.

Moreover, when the user gets to

"-For Butterworth filters no value can be entered and any value 
displayed is ignored."

no value seems to be displayed so there seems to be no need for the 
comment and it might result confusing instead. But it would be useful to 
make clear this: "At the cutoff frequency this filter has an attenuation 
of 3 dB"

As regards

"-For Chebyshev Type I filters type in the acceptable amount of passband 
ripple. Higher values of passband ripple will also increase the cutoff 
slope"

it may be useful to include the trade-off remark by Martyn.

As regards

"-For Chebyshev Type II filters no value can be entered and any value 
displayed is ignored"

again, the "any value displayed is ignored" comment shouldn't be there.

The same is true for the case of the Minimun Stopband Attenuation for 
Butterworth and Chebyshev Type I.

I think Martyn has also pointed this out.

I believe an "application hints" section will be convenient indeed, but 
it should be posponed without preventing the inclusion of the effect.

Regards,

Federico