yes, it's a resistor. Flat as hell. Try to beat that HD800!(this is why you need a colored amp for it, to make up for it's impedance hump.). Yes, damping factor should not come into affect, since there is no resonance, like the dynamics. Get a nice good flat amp guys.
In that case (be still my heart) does an amp like the Mjolnir due justice to the HE 6?