Flangers...

[Lindon]

So Im making an multi-effect - and I'd like to include a flanger - but I cant seem to build or find anything thats fits the bill - the faust one isnt great - and the one In built is wonky - has anyone got any pointers?

[Lindon]

@Lindon perhaps I should have a go at porting the airwindows one...

[DanH]

@Lindon RNBO one was decent

[HISEnberg]

@Lindon Couldn't you just create one in Scriptnode or Faust with a modulated delay?

*Edit here is one I wrote a long time ago when I was learning Faust

declare name "Flanger";
declare version "1.0.0";
declare author "HISENBERG";
declare license "IDGAF-DWYW"; // I don't care do what you want with it

import("stdfaust.lib");

// Mono/Stereo
flanger = _,_ : flanger_stereo : _,_;
flanger_stereo(l,r) = flanger_mono(l), flanger_mono(r);

flanger_mono = effect
with {

    // UI controls
    maxdelay = 0.02;
    rate = hslider("rate[unit:Hz]", 0.5, 0.01, 10.0, 0.01);
    depth = hslider("depth", 0.7, 0.0, 1.0, 0.01);
    feedback = hslider("feedback", 0.5, 0.0, 0.99, 0.01);
    mix = hslider("mix", 0.5, 0.0, 1.0, 0.01);
    
    lfo = os.oscrs(rate) * 0.5 + 0.5; 
    delayTime = 0.0001 + lfo * depth * maxdelay;
    
    // Delay line with feedback
    delayedSignal(x) = fb ~ de.fdelay(maxdlsamps, delaysamples) 
    with {
        SR = ma.SR;                  // Sample rate
        maxdlsamps = int(maxdelay * SR);
        delaysamples = delayTime * SR;
        fb(y) = x + y * feedback;    // Feedback loop
    };
    
    // Mix dry and wet signals
    effect(x) = dry * x + wet * delayedSignal(x)
    with {
        wet = mix;
        dry = 1 - mix;
    };
};

process = flanger;

[griffinboy]

@Lindon

Search for papers and GitHub c++ repos

[DanH]

@HISEnberg

*Edit here is one I wrote a long time ago when I was learning Faust

Do you know how to edit this to allow for an modulation input rather than use the faust lfo?

[HISEnberg]

@DanH You mean more or less like this correct?

You could accomplish it with a simple delay and modulating the delay time. @griffinboy is correct though, reading papers and checking some repos is the way to go here. My example is more or less just a theoretic flanger but doesn't match the performance of what you may find from people who have done actual research on the topic.

But you can try this:

import("stdfaust.lib");

// UI
maxdelay    = 0.5; 
delaytime   = hslider("delay [ms]", 5.0, 0.0, 20.0, 0.01); //Add si.smooth(0.99) for interploation here if you want
feedback    = hslider("feedback", 0.5, 0, 0.99, 0.01);
mix         = hslider("mix",      0.5, 0, 1.00, 0.01);

// State variables
SR          = ma.SR;
maxdlsamps  = int(maxdelay * SR);
delaysamps  = int(delaytime / 1000  * SR); 

// Dleay
delayedSignal(x) = fb ~ de.fdelay(maxdlsamps, delaysamps)
  with { fb(y) = x + y * feedback; };

modDelay(x) = (1-mix)*x + mix*delayedSignal(x);

// Stereo
process = modDelay, modDelay;

[DanH]

@HISEnberg Yup, that's what I meant regarding the input, many thanks! Will do some research

[Morphoice]

@Lindon really depends on what sound and modulation possibilities you want to go for. Whipping up comething custom in faust should be straight forward. Habe a look at the boss or moog clusterlis schematics, they are usually among the most recommended flangers. Probably airwindows is another good source to start and easy to turn into a node. I had a thread how to do it now long ago you should find all you need in there