Doesn't matter what impedance they are. Beyer did a good job of making the beyers sound 98% the same regardless of impedance, with the exception being the 770s which are all over the place. I owned 7 990s of different impedances, and they all sounded basically the exact same give or take a bit of refinement here or there. The general sound was the same. The 880 was a beast even in 32ohm form, but the treble can still be a bit more than people may want.
7/6/14 at 8:44pm