message: Edit Example: replace dual channel input/output with quad channel input/output
diff: #include "State.h"
  extern State myState;
  -AudioInputI2S_F32 i2s_in(audio_settings); //Digital audio input from the ADC over the i2s bus
  +AudioInputI2SQuad_F32 i2s_in(audio_settings); //Digital audio input from the ADC over the i2s bus
  EarpieceMixer_F32_UI earpieceMixer(audio_settings); //mixes earpiece mics, allows switching to analog inputs, mixes left+right, etc
  AudioTestSignalGenerator_F32 audioTestGenerator(audio_settings); //move this to be *after* the creation of the i2s_in object
  @@ -15,7 +15,7 @@ AudioTestSignalGenerator_F32 audioTestGenerator(audio_settings); //move this to
  #define FILTER_ORDER 6 //usually is 6. never tried anything else (like 8)
  #endif
  StereoContainerWDRC_UI stereoContainerWDRC; //helps with managing the phone App's GUI for left+right. In AudioEffectMultiBandWDRC_F32.h
  -AudioOutputI2S_F32 i2s_out(audio_settings); //Digital audio output to the DAC via the i2s bus. Should be last, except for SD writing
  +AudioOutputI2SQuad_F32 i2s_out(audio_settings); //Digital audio output to the DAC via the i2s bus. Should be last, except for SD writing
  AudioSDWriter_F32_UI audioSDWriter(audio_settings); //this is 2-channels of audio by default, but can be changed to 4 in setup()
  //complete the creation of the tester objects
  