qu11355My self own all those X2, M100, Momentum, Fostex th00, AKG 7xx, M50X, NAD HP50, Bose 25, UE6000, Beats Studio 2, B&W P7, ++++etc, all absolute perfect match
qu11355its depend on what amp/ dac you are using, X2, AKG7XX and HD600 actually need higher power amp to drive even though X2 AKG7XX are low imp., those open back headphone sound leak and driver's air push out need better bass amp to punch, that's one of the reason. IMO X2 sound better than AKG7XX, if u are bass lover I prefer not to buy either AKG7xx and Bose qc25, cause X2 bass already the best after Voda M100. Bose qc25 is only good Noise CAncelling but the sound isn't real good.