What he's not saying is the setups are not in the same location.  What really happens is the Earth's magnetic field is not the same force and/or direction from one setup to the other.  This has very drastic effects on the dynamics of the headphone's drivers.  The Earth's magnetic fields will disturb the shape of the driver's magnetic field and cause non linearity.  As the coil moves out of the magnet, it gets pushed away from the toroidal magnetic field's axial line of movement.  This bends the driver's diaphragm, leading to distortions and muffling of the lower frequencies. 



The solution is to place a good quality compass right where your head is when you wear the headphones and place your head so that the Earth's magnetic field is parallel to a line that goes trough both drivers.  That way the Earth's magnetic field will be in line with the magnet's linear axis.  Sadly it's impossible to get a real perfect axis matching with the Q701 as the drivers are angled with each others.  This is why these headphones have so little authority in the lower registers.  People who find them to be well balanced and like their bass are just lucky: at their place, the Earth's magnetic field makes a bend, having a perfect linear fit with each driver's angle.