Sennheiser HD 660S
The perfect blend of power and control, the HD 660S is a powerhouse open-back headphone with the versatility to connect you to the deepest corners of your music collection.
Known for their engaging signatures and liquid-smooth response, HD 660S predecessors HD 650 and HD 600 shattered performance barriers in the audiophile headphone category. The HD 660S transcends the best of that storied DNA with supernatural speed and effortless instrument reproduction—even at the bookends of the frequency spectrum. Utilizing an all-new transducer and specially ventilated drive unit, the HD 660S delivers the revealing, tack-sharp detail audiophiles demand without sacrificing the engaging dynamics that make music so enjoyable.
In just one listen you will understand why the HD 660S is so special. Thousands of listening sessions later its purpose is even clearer. What you hear each and every time is the result of an open-back earcup mated to a new transducer tuned for the modern audiophile. Its speedy response is perfectly suited for reproducing those frequency-stretching recordings with confidence. Thanks to an aluminum voice coil, the 38mm diaphragm remains nimble for ultra-quick impulse fidelity across the board. This activation and rest behaviour unlocks the capability to communicate tonal and spatial characteristics precisely.
The steel mesh found on the HD 660S drive unit is interesting in design but most impressive when it comes to performance. It completes the ventilated driver, offering consistent control of air displacement to reduce turbulence. As a result, diaphragm travel is pure, letting the music—and only the music—shine in a perfect balance of integrity and expression. The steel composition allows for much tighter production tolerances, ultimately contributing to remarkably consistent characteristics of each HD 660S produced. When combined with the open-back earcups, the sound emanating from each transducer is completely free to expand, just as it would in nature.
Today’s audiophile has more component choices than ever. We optimized the HD 660S for efficiency on a wider range of devices to accommodate the varying levels of power present in output amplification circuitry. At 150 ohms, the HD 660S is the perfect partner for dedicated amplifiers, A/V receivers, and audio interfaces alike—the magnet is more powerful than its predecessors, and thus easier to drive regardless of how your setup changes over time.
We packed your HD 660S with a versatile set of essential cables, each one impedance-matched with ultra-low capacitance. The ¼-inch / 6.3mm stereo connector offers the audiophile-standard plug for connection to devices such as headphone amplifiers and A/V receivers, digital audio players, computer-based workstations, analog gear, and more. A balanced, 4.4mm connector opens a pathway to a newer generation of balanced output devices (headphone amplifiers, digital audio players, etc.) that embrace this compact plug’s superior stability over time. A balanced headphone setup offers an even lower noise floor with great dynamic range when connected to balanced source/amp circuit outputs. The listener will thus experience a wider soundstage, tightly controlled transients and impossibly-clear instrument separation. Each cable is 9.8 feet / 3m long to accommodate unencumbered listening on gear deep within your shelves, studio, or desktop, and a flexible adapter is included to reduce the 6.3mm to 3.5mm. An optional balanced cable (CH 650 S) is sold separately for simplified connection to 4-pin XLR jacks.