Yeah, as far as sub bass goes, it's really simple because it has to be. Too many frequencies playing at once down low will sound muddy and cancel each out. You can't really get complex sounds going until your about two octaves above the fundamental. There's really only room for these three frequencies in that really low bass: the fundamental (needs to be a sine), an octave, and an octave and a half. The higher you go, the more complexity you can add. After that, there's all sorts of synthesis to be done to create harmonics and partials to flavor the sound. You can add interest to the bass without adding extra frequencies too, i.e. pitch slides, opening/closing a filter, etc...
