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Product Description

Enjoy your music on a completely new level. An intimate, relaxed sound signature combines with outstanding precision and exceptional comfort - and now, extended sub bass - for a deeply moving experience. The extremely precise yet non-fatiguing sound of the HD 660S2 delivers even more impact with extended sub bass.

With an optimized surround, transducer airflow, and coil our engineers doubled the sound pressure at the lowest octaves. You can feel the lowest note on the piano (27.5 Hz) or the kick of the bass drum (45-60 Hz) as if you were there.

The relaxed tone and open-back design make this extremely comfortable headphone great for long sessions. With warm tuning, smooth treble, and strong bass, the standard-setter for extended listening is now the standard-setter for extended bass as well.


  • This warm, inviting signature combined with extended sub bass makes listening uniquely pleasant and rewarding. And with comfort this good, it practically begs you to keep going for endless sessions. That's how HD 660S2 combines the best of many worlds to give you an intimate experience you won’t want to live without
  • Natural, relaxed, high-fidelity sound with extra sub bass: Optimized surround and diaphragm with new voice coil with 300-ohm impedance
  • 38mm high-performance transducers built in Ireland: Steel mesh damping follows the driver's geometry to control air displacement, while the magnetic yoke includes milled air vents for optimal ventilation, which minimizes distortion
  • Uniquely powerful vented magnet system for minimized distortion
  • Ultra-light aluminium voice coil with 300-ohm impedance for excellent impulse response
  • Intimate sound with great timbre and deep, accurate sub bass


  • Exceptional comfort and build quality: The open-back design and plush ear cushions offer exceptional breathability for long listening sessions
  • The velour earpads of the HD 660S2 can only be described as a tactile pleasure
  • The low total weight and ergonomic headband rule out any potential discomfort on top of your head as well. Combined with excellent build quality made in Ireland, you’ll quickly grow attached to a listening experience that's as physically pleasing as the warm, non-fatiguing sound at its heart
  • Global 2-year warranty offers peace of mind for your audio equipment investment

General Data

Transducer principle Dynamic open
Transducer size 38 mm
Frequency response 8 Hz - 41,500 Hz
Impedance 300 Ω
Sound Pressure Level (SPL) 104 dB (1 V)
Total Harmonic Distortion (THD) < 0.04% (1 kHz, 100dB)
Style Over-ear
Weight 260 g
Adapter 6.3 mm (1/4 inch) to 3.5 mm
Connector 6.3 mm (1/4 inch) jack plug, 4.4 mm balanced plug
Cable length 1.8 m
Country of origin Ireland
Magnetic field 2.5 mT

What's in the box

  • HD 660S2 headphones
  • 6.3 mm cable (1.8 m), 4.4 mm cable (1.8 m)
  • 6.3 mm to 3.5 mm adapter
  • Carry pouch


Product Code

Delivery Information

Delivery is free for all orders over £250.

'In Stock' items ordered before 1pm will be dispatched the same day.

We use DPD Local 'Next Day Service' for most UK deliveries. Orders sent via 'DPD Local - Next Day Service' will be fully tracked with a 1-hour delivery timeslot on the day of delivery. Standard delivery is Monday to Friday.

Saturday delivery can be selected at checkout for £19.95.

Small items and LP's may be sent using Royal Mail.

Large/heavy items may be sent using TNT Express.

For all other countries please visit the 'Delivery Information' link in the footer.

Occasionally, due to stock demand, we can sell out. If this occurs when you make a purchase, we will inform you quickly. Most out of stock items are available for dispatch within 3 working days. If your purchase is urgent, please contact us to check availability.

Customer Reviews

Sennheiser HD 660S2 Open Back Headphones

Item in Stock

Product Code SENN-HD660S2

Customer Reviews