I own several high-level headphones, but jai low for Beyer especially that it is the least expensive high-end helmets. The equation helmets can be summarized in two words: comfort / musicality in the sense quon want AKG 701 is more neutral but excels especially on chamber music pity that his blindfold to "bumps" make me a headache, the Sennheiser HD 600 is fantastic, better than Beyer but it too tight while the ears comforts Beyer DT 990 is perfect, no fatigue after hours of plays, only lAkg 242 (with velvet pad) or the old Sennheiser 560 ovation provides such a feeling commode. This helmet is not really neutral, but its small loudness effect is really significant about rock and modern music. For the classic I take the Sennheiser cursing against its arch. I do not think it is difficult to Beyer driver despite its rather high impedance, anyway a real audiophile listen with a headphone amp info dédié.Petite way, disassembly for possible service (although it is built like a tank dassaut !) is dune ease, over all parts are and will be available much longer. In short (especially at this price!) Perfection is (almost) in the world!