message: Example: SoundLevelMeter: adjust the cal for PCB mics
diff: /*
  * SoundLevelMeter
  *
  -* Created: Chip Audette, OpenAudio, Apr 2017
  +* Created: Chip Audette, OpenAudio, June 2018
  * Purpose: Compute the current sound level, dBA-Fast or whatever
  * Uses exponential time weighting, not integrating.
  *
  @@ -36,7 +36,8 @@ AudioConnection_F32 patchCord4(i2s_in, 0, i2s_out, 0); //echo the ori
  AudioConnection_F32 patchCord5(calcLevel1, 0, i2s_out, 1); //connect the Right gain to the Right output
  //calibraiton information for the microphone being used
  -float32_t mic_cal_dBFS_at94dBSPL_at_0dB_gain = -47.4f; //PCB Mic, http://openaudio.blogspot.com/search/label/Microphone
  +//float32_t mic_cal_dBFS_at94dBSPL_at_0dB_gain = -47.4f ; //PCB Mic, http://openaudio.blogspot.com/search/label/Microphone
  +float32_t mic_cal_dBFS_at94dBSPL_at_0dB_gain = -47.4f + 8.4575; //PCB Mic baseline with manually tested adjustment. Baseline: http://openaudio.blogspot.com/search/label/Microphone
  //other variables
  #define BOTH_SERIAL audioHardware
  