Hi I'm new to sound generation.

I'm trying to make a pitch pipe sound that is reliable for a singer with an Android phone.

So far, I have an oscillator that outputs whatever frequency I want to input.

When the frequency is low like the pitch C3, I do not hear anything.

Also, the volume is not consistent for different pitches.

Thank you in advance for trying to help me.

Here's the pitch pipe sound I want to emulate:
http://www.harmonize.com/metropolis/images/Sounds/CNatural.mp3

The patch I made is a derivative of the GuitarTuner Android app example.

I'm new to the waves and filtering. Hopefully the pitch pipe example helps you
to explain what waves and filters would get that sound.

http://www.pdpatchrepo.info/hurleur/pitchpipe.pd