SENNHEISER

HD 660S2 Open-back Audiophile Headphones (Parallel Import, One-Year Warranty)

SENNHEISER HD 660S2 inherits the legendary lineage of the HD 600 series (HD 580, HD 600, HD 650, HD 660S) and represents the latest evolution of Sennheiser's most iconic neutral sound signature. The new generation driver returns to the classic specification of 300Ω impedance, with an improved voice coil that provides stronger magnetic force and electrical damping, combined with a more compliant surround design that lowers the resonance frequency to 70 Hz, resulting in a significant increase in sub-bass sound pressure without losing precise balance. The unique powerful vented magnet system minimizes distortion, while the ultra-light aluminum voice coil delivers outstanding transient response. The soundstage reveals a greater sense of space, with higher frequencies appearing more brilliant and emotions more moving. The velvet ear pads, along with the open-back design, ensure comfort during long listening sessions; designed in Germany and manufactured in Ireland, it comes with one 6.3mm and one 4.4mm balanced cable.

• Want the latest version of the Sennheiser legendary HD 600 series neutral-sounding headphones?
• Prioritizing bass — Subwoofer sound pressure level increased while maintaining accuracy, satisfying bass enthusiasts.
• Pursuing top-tier craftsmanship — German design, Irish manufacturing, featuring 6.3mm + 4.4mm dual wires.

Q. What are the differences between HD 660S2 and HD 660S?

The impedance of the S2 version has been changed back from 150Ω to the classic specification of 300Ω, with stronger voice coil magnetism and damping, and a more compliant suspension that lowers the resonance frequency to 70 Hz, doubling the subwoofer sound pressure; overall accuracy, speed, and resolution have been improved.

Q. Will the 300Ω be difficult to push?

It is recommended to use with a headphone amplifier or a stronger DAP for optimal performance; the included 4.4mm balanced cable is specifically designed for use with balanced output headphone amplifiers/DAPs. The direct output volume from a typical smartphone may be relatively weak.

Q. Why do enthusiasts talk very little about subwoofers?

Traditional high-fidelity headphones often produce loose and booming bass, but the HD 660S2 doubles the lowest frequency sound pressure while maintaining precise balance, allowing the bass to dive deeper, which in turn makes the high frequencies more brilliant and the soundstage deeper.

Q. Where does the open design fit?

Suitable for quiet home environments. Open-plan layouts will leak sound and allow you to hear ambient noise, making them unsuitable for public transportation or shared offices.