Filter 3 Cutoff Modulation ....nasty Sound

Like keithe 303 mentioned somewhere in the forum , how about an update to the filter cutoff , currently when modulating the cutoff this results in unwanted artifacts …zippery noise …especially the butterworth and svf filter …

Um, forgive me if these are obvious questions: Have you tried adjusting the Inertia slider to compensate? Made sure that all automation data is curved?

I think I know the noise you are talking about, but it may be common to all digital parameters trying to emulate continuous analogue effects?

I believe the sound he’s referring to may be caused by aliasing. If so wouldn’t it be possible to use a static filter before the output to stop aliasing?

man a filter’s gotta do what a filter’s gotta effin do.

oh boy , people I’ve been making music for over ten years ,reaktor , nord modular various hardware , I have knowledge about synthesis etc…I know when a filter aliases and when it just sounds bad …filter 3 sounds bad when modulatig the cut( off …yes the inertia slider doees resolve this a bit …but the artifacts are stil there …just filter a static wave with a few harmonics ( the errors will be more clearly ) and put on the butterworth …urrgh
I rebuild a lot of renoise internal effects in reaktor just because they do sound better in reaktor …
So please improve filter 3

aliasing occurs when frequencies are folded back etc… …this is not the the case …I am just referring to a nasty zippery sound …hardly audible but still present

Ok, so maybe to clarify (because we were all off the mark to begin with), can you put up two examples: 1. The filter moving on a sound where the distortion is evident, and 2. The same movement on the same sound with a 3rd party filter that doesn’t have the problem. Then we’ve got some hard evidence we all can refer to. :)

Just take a basic wave like a triangle or sine , one that doesn’t have many harmonics or none at all , this way we can really hear the disturbing zippery noise thats occurs when modulating the cuttof …now select the butterworth filter and drag the frequency slider slooooowly …if you listen carefully you’ll hear a zippery noise ( this has nothing to do with buffering issues or aliasing issues …) it is just how the filter behaves …and I think there can be done something about it .
Yeah ofcourse there will be third party filters that behave equally bad , but the contrary is also true …be it freeware or third party .
Of course when you filter a harmonically rich sound like a saw wave , the errors will be less audible …

you can see pretty much what goes on in the spectogram (sine wave + filter butterworth 4n changing cutoff around the note’s frequency up&down).

I don’t know if this is the problem zipper sound I mean , looking at your picture there are frequencies/overtones ( between 500 and 1000) above the fudamental sine wave ( 300 hz ) and a lot of low content below .
Do the frequencies above the fundamental occur when modulaing the cuto ff ? , if so …that’s the zippery sound …it also occurs with all the other filter types , except the moog style filter which behaves slightly better

yeah I didn’t use a clean sine wave…

the sounds just rumbles… and i also have it with the moog filter (but less)…

The zipper sound should be around 5khz >>>for some reason my bnoxnet account isn,t working I will upload a file later on ,
When you filter a sine wave ( there is not really anything ,harmonics to filter out ) the rumble that you describe occurs when the cutoff freq . has reached the same freq. as the sinewave you are filtering , thus cutoff at 500 hz , filtering a 500 hz sine wave , thats absolutely normal .
The zipper sound I am talking about is because of inferior coding of the filter …the zipper sound is way above 1000 hz, set spectrogram to maximum slope and filter a sine wave …then look at the higher frequencies , these will be introduced when you drag the cut off slider

here it is

i see

Great , so can this problem be resolved ( not using the inertia slider ) but better filter behaviour , a commment from one of the developers would be nice .

dev’s please don’t ingnore this thread …

I’m pretty sure no thread gets ignored. Whether or not they can do anything practical about this within a update period is another matter and one we’re not qualified to comment on. You’ve pointed out the issue very clearly, the rest is in their hands and our patience.

i’m all for a nu filter also. the moog mode is not so bad but the other one doesn’t really sound good
filter is such a creative effect i would be cool to have a good one in renoise. like some kind of bifilter with serial, parralel, morph possibilities. with distorsion like the fxpansion filter.
that would be so cool and usefull !

Yeah sure distorted filter can sound cool , but this is no ddistortion ,its bad interpolation or whatever it’s called …the fact that you can HEAR the slider move ( the crackles ) in the upper freq’s ., dowload the file above and see .
Filter 2 doesn’t have the zipper noise but the overall quality is inferior ( personal taste ) I mean the filter 2 moog type at reso 1.0 is shamingly bad , the maximum resonance should be a 0.89 everything above that distorts in a bad way .

Maybe time for a Filter 4 ?