CanadianMaestro
Headphoneus Supremus
Good though they are, I don't find the HD650 an ideal can for the punctate detailed, open, deep, spacious, holographic sound of a large orchestra. My preferences for this type of music are the DT88O, an AKG like the 712, or even the HP100 and 200. The Polaris synergises beautifully with all these, on mid or high gain, low output impedance and high bandwidth. The AKG 701 is also very good, though I lower the bandwidth to the mid setting for these cans. That's the beauty of the Polaris, it's so adaptable.
I agree about 650 and large-scale symphonic music (have posted on a few threads this observation).