Are there different meanings behind digital to analog in digital audio and PWM?
A DAC is mostly refered to as a device that converts a digital signal (a number) into a value discrete voltage signal followed by a zero order hold. A DAC doesn't use PWM. Class D amplifiers use PWM to drive the speakers and do already provide very smooth currents. If you want to smooth these currents further, you can add a two stage lowpass T-Filter right after the amplifiers output.