Pi4 + CamillaDSP + Audio Interface (Motu M4) = Phenomal DSP streamer

[gwur]

For those still playing along here is the config for Moode Audio 8.2.4. The setup is a 2.1 stereo, crossover at 100Hz, high and low pass filters are set to butterworth 4th order for 24dB/octave roll off, single line level input to the subwoofer combining L and R channels at -6dB each, and samplerate set to 96000 with resampling turned on.

In Moode Audio configuration:
Output Device - M4
Volume Type - Software

Create camilladsp file /usr/share/camilladsp/configs/motu4.yml
*Enable resampling as needed

devices:
  adjust_period: 10
  capture:
    channels: 2
    extra_samples: 0
    filename: /dev/stdin
    format: S24LE
    read_bytes: 0
    skip_bytes: 0
    type: File
  capture_samplerate: 96000
  chunksize: 1024
  enable_rate_adjust: false
  enable_resampling: true
  playback:
    channels: 4
    device: hw:CARD=M4
    format: S32LE
    type: Alsa
  queuelimit: 1
  rate_measure_interval: 1
  resampler_type: BalancedAsync
  samplerate: 96000
  silence_threshold: 0
  silence_timeout: 0
  stop_on_rate_change: false
  target_level: 0
filters:
  Speakers:
    parameters:
      freq: 100
      order: 4
      type: ButterworthHighpass
    type: BiquadCombo
  Subwoofer:
    parameters:
      freq: 100
      order: 4
      type: ButterworthLowpass
    type: BiquadCombo
mixers:
  ToM4:
    channels:
      in: 2
      out: 4
    mapping:
    - dest: 0
      mute: false
      sources:
      - channel: 0
        gain: 0
        inverted: false
        mute: false
    - dest: 1
      mute: false
      sources:
      - channel: 1
        gain: 0
        inverted: false
        mute: false
    - dest: 2
      mute: false
      sources:
      - channel: 0
        gain: -6
        inverted: false
        mute: false
      - channel: 1
        gain: -6
        inverted: false
        mute: false
pipeline:
- name: ToM4
  type: Mixer
- channel: 0
  names:
  - Speakers
  type: Filter
- channel: 1
  names:
  - Speakers
  type: Filter
- channel: 2
  names:
  - Subwoofer
  type: Filter

Go to Moode Audio's CamillaDSP configuration and set:
Signal processing - motu4
Default device - no
Pipeline configuration - motu4

Add further adjustments as needed.