Using AudioEffectStream with FilteredStream

[GFelipeSanchezS]

I am trying to make a sound board with my ESP32-AudioKit and I have a a wave generator that I am adding effects to.

AudioBoardStream kit(AudioKitEs8388V1);
SawToothGenerator<int16_t> sine;
GeneratedSoundStream<int16_t> sine_stream(sine);
AudioEffectStream effects(sine_stream);
StreamCopy copier(kit, effects);

I want to be able to put a Low-Pass on the stream with FilteredStream AFTER the effects are applied as they are causing a high freq I want to get rid off.

WaveGen -> Effects -> LowPass -> I2S (AudioBoardStream)

However, I am uncertain on how to go about it. Should I have a second StreamCopy to copy back to kit? Thank you for your help.

Similar Issue: #1560 (comment)

[GFelipeSanchezS]

// Audio components
AudioBoardStream kit(AudioKitEs8388V1);
SawToothGenerator<int16_t> sine;
GeneratedSoundStream<int16_t> sine_stream(sine);
AudioEffectStream effects(sine_stream);
FilteredStream<int16_t, float> filtered(effects, 2);
StreamCopy copier(kit, filtered);

// Effects
ADSRGain adsr(0.001, 0.0001, 0.9, 0.0002);
int16_t clipThreshold = 5000;
Distortion distortion(clipThreshold);
Tremolo tremolo(0.35, 2.0);
LowPassFilter<float> lowPassFilter(350, 44100);

// ... code ...

void setup() {
  // ... code ...
  // Add effects
  effects.addEffect(distortion);
  effects.addEffect(tremolo); 
  effects.addEffect(adsr);

  // Setup output
  auto cfg = kit.defaultConfig(TX_MODE);
  cfg.sd_active = false;
  kit.begin(cfg);
  kit.setVolume(80);
  filtered.setFilter(0, lowPassFilter);
  filtered.setFilter(1, lowPassFilter);

  // Setup sound generation
  sine.begin(cfg, 0);
  sine_stream.begin(cfg);
  effects.begin(cfg);

  // Activate keys
  setupActions();
}

void loop() {
  copier.copy();
  kit.processActions();
}

Current code does not work, as waves over 350Hz are still passing.
Using LowPassFilter as per documentation: https://pschatzmann.github.io/arduino-audio-tools/classaudio__tools_1_1_low_pass_filter.html

[pschatzmann]

Please follow the instructions given here before posting a question.

I added a test sketch that shows the default filter profile for the default Q value. Feel free to adjust this parameter to your needs or design your own filter that meets your requirements. There is a Wiki for this!

Please note, your sketch contains a bad error: if you reuse the same filter for different channels you are messing up the signal quite badly!