the principle of nearfield monitoring, made to suppress room influence by shorter distance to the ears.
I wouldn´t call my own monitoring situation "nearfield" at 5ft distance to the ear anymore, but technically it might still be.
ear height doesn´t necessarily have to be, it´s a good starting point though. depends on the monitors´ frequency response on and off axis. I decided to give mine a ~10° angle, because otherwise the top-end is too prominent
Luther´s Dungeon Studio