When trying to create high-quality sound, you need to consider the
following factors:

   *  Waveform transitions.
   *  Sampling rate.
   *  Efficiency.
   *  Noise reduction.
   *  Avoidance of aliasing distortion.
   *  Limitations of the low pass filter.

 making waveform transitions      noise reduction 
 sampling rate                    aliasing distortion 
 efficiency                       low-pass filter