FabFilter

Hi, it looks like the band pass, notch and band stop filters in your plugin incorrectly have the wrong slopes i.e. a 12dB/octave band pass only has the same slope as a 6dB/octave high cut - what's that about?

Hi Keith,

You're correct that in Pro-Q 2, a 12 dB/oct Band Pass filter has the same apparent slope as a 6 dB/oct High Cut filter. That's because 6 dB/oct means that the filter is implemented as a first order filter. A band pass filter with the same slope needs twice the complexity of a first order filter, because it also needs to filter away the low frequencies. So it's implemented as a second order filter, which corresponds to the 12 dB/oct slope setting.

So in Pro-Q 2 (and generally in all EQ plugins), the slope setting directly corresponds to the order of the filter, and not necessarily to the actual slope of the filter as you see it in the graph. Hope this helps!

Cheers,

Hey Frederik,

I think I got the idea, but isn't it a bit awkward that the 'dB/Oct'doesn't represent the actual slope?

I mean, why wouldn't you call it by the actual slope, and 'under the hood' it will be the second order filter?

Just out of curiousity :}
(As you said, it's like that it all EQ plugins, for a reason, I guess?)

If we would call the 12 dB band pass a 6 dB/oct filter... that would really confuse everyone who has ever used a band pass filter in another plugin or even analog equalizer. :-)

Cheers,

I see, well, that makes sense :}

Thanks !