OHMS: 4ohm, 8ohm and 16 ohm amp taps

Is there any expected character change depending on what tap you use. ie will using the 4 ohm tap always give a tighter but harder sound and as you go up to the 8ohm tap, the sound gets softer? or is it different from amp to amp and speaker to speaker and more down to matching/ experimenting with no real pattern?

Dip in and out HERE