Review
AI summary based on real user insights
The Sennheiser HD 660S2 is a reference-class open-back headphone tuned for natural, accurate sound reproduction — the 300-ohm impedance and updated dynamic driver produce a wide, spacious soundstage with the detail retrieval that mixing engineers and serious audiophiles require. Successor to the HD 650/660S lineage with improved low-frequency extension.
The hand-assembled German construction and replaceable cable system are built for decades of ownership rather than a product cycle, and the comfort over extended listening sessions is among the best available at this driver size. Velour earpads and lightweight headband minimize fatigue.
300-ohm impedance requires a quality headphone amplifier — direct phone or laptop output will produce underpowered, thin sound. The investment in a matching DAC/amp is necessary to hear what the HD 660S2 can actually do. Designed for serious audiophiles, mixing engineers, and long-session music listeners who want reference accuracy and plan to pair the headphones with appropriate amplification.
