ScriptNode - DC. Offset

[Lindon]

Is there a way to do this - Im trying to use a phasor.fm node and its giving me an only positive wave shape back....(as it would)...

[David Healey]

Try a high-pass filter at 5hz.

[Lindon]

@d-healey oooh, yeah, ... nice...

[HISEnberg]

@Lindon This may be helpful as well

https://faustlibraries.grame.fr/libs/filters/#fidcblockerat

[Christoph Hart]

Why not use a mod2sig node?

[Lindon]

@Christoph-Hart tried that - didnt work....dunno why

[ustk]

@Lindon Seems it does work:

[Lindon]

@ustk oh Im not saying it doesn't work - just it doesn't work for a phasor_fm modulated signal...in my case... anyway davids solution worked perfectly...

[Jeetender]

@Christoph-Hart the sig2mod removed dc offset? how to remove dc offset

[ustk]

@Jeetender Not quite, more the opposite in fact since in rescales a -1 to 1 audio signal to a 0 to 1 modulation signal.

To remove DC offset you need a HPF

[Jeetender]

@ustk ive tried the HPF at 5-10Hz.. doesn't seems to be working any specific filter module?

[ustk]

@Jeetender Then your problem might be somewhere else. By definition the DC at the output of any HPF is -inf.
It's right that it can bring artefacts in some cases that are essentially due to its response time, but it definitely kill DC.

[Jeetender]

@ustk said in ScriptNode - DC. Offset:

@Jeetender Then your problem might be somewhere else. By definition the DC at the output of any HPF is -inf.
It's right that it can bring artefacts in some cases that are essentially due to its response time, but it definitely kill DC.

can a regular svf filter in scriptnode do it? or any other dedicated node ?

[Sifres]

@Jeetender yeah the stock one works just fine.

[Jeetender]

@Sifres said in ScriptNode - DC. Offset:

@Jeetender yeah the stock one works just fine.

so a HP at 5hz it is.

[ustk]

@Jeetender Hise HPFs don't go below 20Hz (unless I'm wrong, even if you set the parameter to 5Hz)

But I agree anywhere in the 5-10Hz range is better (the lower you go, the longer the delay response so it's not alway good to go below that, depends on your design)
So if you want to go below 20Hz, you need to wrap your own C++ custom filter (or Faust or other maybe?)

[amirvinci]

@Jeetender It will remove DC. Technically DC is 0hz thus HiPass filtering the lowest frequency i.e. 3,4 or 5Hz will effectively remove the DC.
However, it will introduce phase differences similarly to an all pass filter, thus subtracting it from the original will leave audible residue. That should be Okay and is just like any HiPass based on IIR. You can use an FIR, however to be phase linear it'll have to have a fairly long delay.

[Jeetender]

@ustk said in ScriptNode - DC. Offset:

@Jeetender Hise HPFs don't go below 20Hz (unless I'm wrong, even if you set the parameter to 5Hz)

But I agree anywhere in the 5-10Hz range is better (the lower you go, the longer the delay response so it's not alway good to go below that, depends on your design)
So if you want to go below 20Hz, you need to wrap your own C++ custom filter (or Faust or other maybe?)

well we can go below 20hz in any scriptnode eq. just make the knob sticky and drag the edges to se the range. and yes i used a 5hz hp and its ok doing the job

[ustk]

@Jeetender Hmmm... I'm might be wrong but I'm not so sure about this. You can surely set a parameter to any value below 20Hz, but I'm not sure the filter is capable of reaching this value. To me it's capped to 20Hz-20kHz no matter the range of your parameters.