Problems When Using Filter

Im using the Filter 3 to make the music fade and then turn it back again.
Just automating the cutoff so it will make the effect.

But it sometimes makes a scratchy noise at some point, which I rather would live without.
Have tried to change the inertia, but that didn’t help. Any suggestions on how to avoid that noise?

what type of filter are you using , state variable , moog or butterworth …lp, hp ,bp ??
Resonance cranked up on low pass can cause clipping , but noise ???
Go to automation lane and use line or curve for interpolation

Have you tried to lower the volume of what goes into the filter?

I guess he is using a moog variant somewhere… the moog is known for these kind of scratchy noises if it goes beyond or below a certain threshold.

The problem is actually pretty easy to recreate. I’ve ran into it myself a few times in the past.

It’s easiest to hear when listening on headphones and playing a low note with a pure sound like a sine wave. You can hear the noise while adjusting the cutoff frequency. Increasing the inertia makes it a bit better, but still not perfect. The noise comes from interpolating between the filter co-efficient changes. Intepolation is necessary in order to keep the co-efficient recalculations within a reasonable amount of CPU usage, otherwise it would usually be total overkill to do this on a per-sample basis.

Example: (Renoise 2.6.1)

It affects each filter type a bit differently, but it’s probably worst on the butterworth types which are better suited to static filtering jobs. The noise becomes pretty much non-existent when using the 24dB Moog filter type with low resonance and a bit of inertia to help smooth things out, so if you want to do rapid modulations with a filter then it’s probably best to use this configuration instead.

I think you might have got something.

It might be some sort of clipping, but still it’s not quite, because it sounds like the sound is breaking through a barrier or something.
Im using the LP, 24 dB 4Pole.

Just found out Im unaware of how to add a URL of my .xrns file :S

Could this have something do to with my speakers?

Do you have the song maximized close to -0db before the filter? Filtering can often increase the apmlitude of the signal, especially with the butterworths. Try adding a maximizer after the filter.