For your speaker problem just use 2 8 ohm units in series with the polarity +-+- and voila a 16 ohm speaker. If your layout is spagetti wired and you are concerned about damaging your high priced speach chip just drive a 16 ohm suitable wattage resistor and pick the signal up through a 10 k protection resistor into a cheap audio amp. If your audio chip uses a bridge amp design then isolate both lines and drive a differential input to your audio amp. Hopre this helps Terry