sennheiser hd 660s2 vs audeze mm 100

The Sennheiser HD 660S2 features an open-back design with a 150-ohm impedance and balanced sound, while the Sony MDR-MV1 is closed-back with 24-ohm impedance for better isolation. Reviews favor the HD 660S2 for audiophile listening, but the MDR-MV1 suits spatial audio at a lower price around $300.