How to play:
Left click and drag the [ball, green] circles to change the magnitude of
each Fourier functions [Sin nf, Cos nf].
Right click the mouse button to change the magnitude between 0 and 1.0
Click Play to turn on the sound effect, Stop to turn it off.
The coefficient of sin(0f) is used as amplification factor for all modes.
(Use it to change the sound level)¡Athe coefficient of cos(0f) is the DC
Click the checkbox at the top(after stop) will show square the the amplitude
of the signal.