Add comment to filter example

Audio.cpp

 	s2 = 0;
 	enabled = true;
 	__enable_irq();
-	Serial.printf("Tone: coef=%d, ncycles=%d, length=%d\n", coefficient, ncycles, length);
+	//Serial.printf("Tone: coef=%d, ncycles=%d, length=%d\n", coefficient, ncycles, length);
 }
 
 float AudioAnalyzeToneDetect::read(void)

examples/Filter/Filter.ino

 //const int myInput = AUDIO_INPUT_MIC;
 
 // each filter requires a set up parameters
+//  http://forum.pjrc.com/threads/24793-Audio-Library?p=40179&viewfull=1#post40179
+//
 int myFilterParameters[] = {  // lowpass, Fc=800 Hz, Q=0.707
   3224322, 6448644, 3224322, 1974735214, -913890679, 0, 0, 0};