Posted on May 17, 2011 at 14:00The DAC will put out 0 volts for a DAC output register value = 0 and DAC reference voltage (usually 3.3 volts) for a DAC output register = 4095, and intermediate voltages for intermediate register values.
Sound occurs when a sequence of numbers is converted to a voltage to produce a changing waveform. So when the DAC register doesn't change (at any value), the speaker is not vibrating, so there is no sound.
Your challenge is to find out what range of numbers is coming out of the wave file and rescale if necessary to fit the 8 or 12 bit DAC range so you get reasonable accuracy without clipping.
Cheers, Hal
