Sennheiser is renowned for producing high-quality audio products, and the HD660S2 headphones are no exception. These open-back over-ear headphones are designed to deliver an exceptional listening experience, especially for audiophiles and discerning music enthusiasts.
Starting with the build and design, the HD660S2 showcases a classic yet premium look. The construction is sturdy, featuring a combination of metal and high-quality plastic materials that contribute to their durability while maintaining a relatively lightweight design for extended comfort during extended listening sessions.
One of the standout features of the HD660S2 is its open-back design. This design choice provides a spacious and airy soundstage, allowing the music to breathe and creating a more natural listening experience. It also aids in preventing the buildup of heat and pressure, making these headphones suitable for extended usage.
Sound quality is where the HD660S2 truly shines. Equipped with Sennheiser‘s proprietary transducer technology, these headphones deliver a balanced and detailed sound signature. The bass response is tight and controlled, without being overpowering, ensuring that each instrument and vocal stands out distinctly. The midrange is warm and expressive, making vocals sound clear and natural, while the treble is crisp and well-extended, adding sparkle to the high-frequency range.
The HD660S2 boasts impressive transparency and clarity, capturing even the subtlest nuances in the music be it jazz or heavy metal. Audiophiles will appreciate the accuracy and precision in reproduction, making these headphones suitable for critical listening and studio work.
Comfort is essential for long listening sessions, and Sennheiser has put considerable effort into ensuring the HD660S2 excels in this regard. The plush, soft, replaceable earpads and adjustable headband contribute to a comfortable fit for various head sizes (I have a fat head). However, as an open-back design, the headphones lack noise isolation and are better suited for quiet environments where sound leakage won’t disturb others.
Another noteworthy feature is the detachable cable, which provides versatility and allows users to use different cable options depending on their needs or preferences. Additionally, Sennheiser has included a 6.35 mm to 3.5 mm adapter, enhancing the HD660S2’s compatibility with a wide range of audio equipment from professional studios down to portable uses.
Although the HD660S2 is an outstanding pair of headphones, it’s essential to consider their intended use. Due to their open-back design, they may not be the ideal choice for use in noisy environments or public spaces where isolation is crucial. Moreover, they require ample power to reach their full potential, so pairing them with a dedicated headphone amplifier such as the FiiO K3 used in this review is recommended for the best performance.
In conclusion, the Sennheiser HD660S2 headphones are a top-tier choice for audiophiles seeking an authentic and detailed listening experience. With their open-back design, impressive sound quality, and comfortable fit, they excel in providing an immersive and natural soundstage that brings music to life. While not suitable for every situation, these headphones are a solid investment for those who prioritize audio fidelity and appreciate the craftsmanship that Sennheiser consistently delivers.
