ok, i gave up on using PWM for the speakers, and decided to use the 12-bit DACs instead. the voltage in on the TDA2822D looks to be around 0.06V and that gives approximately a 2V swing on a 5V rail. i'll experiment a bit more, try to find a random 470uF capacitor for use on the output (i'm only using 100uF at the moment), this should give a larger output range.
... it's getting there.
l.