Key Features

Dynamic Audiophile Headphones
Open-Back Design for Long Sessions
Extended Sub-Bass Response Down to 8 Hz
Tolerances for ±1 dB Accuracy
Detachable Cables
Ultralight Aluminum Voice Coils
Stainless Steel Mesh Damper
Channel Matched Drivers
Includes Carry Pouch and 3.5mm Adapter

Dive Deeper into Your Music

Enjoy your music on a totally new level with the HD 660S2 from Sennheiser, the improved successor to the HD 660S with audiophile specs and greatly enhanced bass response. The HD 660S2 delivers a deeply moving auditory experience thanks to features like an optimized steel mesh surround, improved transducer airflow, and lighter weight, higher impedance aluminum voice coils, which deliver more impact and extended sub-bass performance, so you can hear the lowest pianos notes and the deepest bass drum hits without sacrificing comfort or natural sound reproduction.

The open-back design and ultrasoft velour earcups of these over-ear headphones ensure extreme comfort during extra-long sessions, and perfectly channel-matched drivers within ±1 dB provide a truly intimate, high-fidelity listening experience. The HD 660S2 comes with two detachable cables in 1/4" unbalanced and 4.4mm balanced flavors, and the headphones also include a handy 1/4" to 3.5mm adapter and a convenient carry pouch.

More Impact and Emotion

Sub bass expands the entire sound. In doubling the sound pressure at the lowest frequencies, Sennheiser has retained extraordinary precision and balance throughout the sub-bass, mid-bass, and beyond.

Extension on the low-end changes everything by creating more space for the sound. Against a deeper backdrop, highs feel more brilliant, the soundstage deeper, and the emotions stronger.

Headphones that Feel as Great as They Sound

The velour earpads of the HD 660S2 can only be described as a tactile pleasure. With just the right amount of tension for proper acoustic positioning and supple padding, the headband won't draw attention away from your music either.

The open-back design gives your ears an extremely comfortable climate, even for super-long sessions, and the low total weight and ergonomic headband rule out any potential discomfort. Combined with excellent Irish build quality, the listening experience is as physically pleasing as the warm, non-fatiguing sound at its heart.

Update to a Legend

High-end Sennheiser headphones have inspired generations with their balanced, natural reproduction. Recognized as benchmarks for neutral audiophile sound, the HD 600, HD 650, and HD 660S share visible and audible DNA with the HD 660S2. The revised coil of the HD 660S2 matches the 300-ohm impedance of the legendary HD 600 and HD 650.

This new coil also provides higher magnetic force and electrical dampening for cleaner impulse response. The surround is also more compliant, dropping the resonant frequency to 70 Hz. All together, these measures result in even greater precision, speed, and resolution, with double the sound pressure at the lowest frequencies.

Key Technical Highlights

Optimized airflow around the transducer, decreasing air leakage and increasing low-frequency acoustic pressure
Lightweight Duofol aluminum voice coils with 300-ohm impedance for better electrical damping and improved detail retrieval
Twice the sound pressure than previous models at 20 Hz, improving the impact of percussion and electronic music
Stronger response above 5 kHz for more perceived clarity, smoother response for more natural reproduction
Uniquely powerful vented magnet system for minimized distortion
38mm high-performance dynamic drivers
Steel mesh baffle for less permeability and increased but natural bass response
Excellent balance and superior imaging through matched acoustic systems

SPECIFICATIONS

Wearing Style	Dual Ear with Headband Foldable: No Earpiece Swivel: No
Earpiece Design	Over-Ear (Circumaural)
Open/Closed-Back	Open-Back
Sound Field	Stereo
Driver Type	Dynamic
Driver Size	1.5" / 38 mm
Impedance	300 Ohms
Active Noise Cancellation	No
Frequency Response	8 Hz to 41.5 kHz
Sensitivity	104 dB SPL/V
Maximum Sound Pressure Level (SPL)	104 dB
Built-In Controls	No
Built-In Mic	No
Audio Connector	1x 1/4" TRS 1x 4.4 mm TRRRS
Included Adapter	1/8" / 3.5 mm TRS
Cable Design	Detachable / Straight
Cable Length	5.9' / 1.8 m
Color	Black
Environmental Resistance	No
Box Dimensions (LxWxH)	10.7 x 7.5 x 4.1"
Weight	9.2 oz / 260 g
Package Weight	1.405 lb

Sennheiser HD 660S2 Wired Over-Ear Headphones