what are the units of "rolloff" for the Elliptic filters?

vinniefalco / DSPFilters

A Collection of Useful C++ Classes for Digital Signal Processing

1.79k stars 371 forks source link

what are the units of "rolloff" for the Elliptic filters? #47

Open squinkylabs opened 5 years ago

squinkylabs commented 5 years ago

In the Elliptic filter designers, rippleDB is in DB, of course. Order and frequency are pretty clear. But what is rolloff? Is it decibels per octave? decibels?

Stefeg commented 5 years ago

I have the same question

jmidt commented 3 years ago

@squinkylabs @Stefeg Did anyone figure this out? I have been looking over the math, but I can't see how this is related to the more standard filter parameters, such as the stopband attenuation.

squinkylabs commented 3 years ago

no as far as I know.