DD4WH
Senior Member

You could use the built-in Teensy Audio Library Look for examples in Arduino IDE, maybe try this IIR example: https://github.com/PaulStoffregen/Audio/blob/master/examples/Effects/Filter/Filter.ino

Try adding this under the audio connections. AudioControlSGTL5000 codec; An external codec needs that to be enabled, if I remember correctly.

Wes, have a look here: http://www.janbob.com/electron/OpenAudio_Design_Tool/index.html https://github.com/chipaudette/OpenAudio_ArduinoLibrary Chip Audette and Bob Larkin have done a great job!