SENNHEISER High-definition headphones featured

SENNHEISER High-definition headphones Manual

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SENNHEISER High-definition headphones Manual

SENNHEISER High-definition headphones

Important safety instructions

  • Read this instruction manual carefully and completely before using the product.
  • Always include these safety instructions when passing the product on to third parties.
  • Do not use an obviously defective product.

Preventing damage to health and accidents

  • Protect your hearing from high volume levels. Permanent hearing damage may occur when headphones are used at high volume levels for long periods of time.
  • The product generates stronger permanent magnetic fields that could cause interference to cardiac pacemakers, implanted defibrillators (ICDs), and other implants.
  • Keep the product, accessories, and packaging parts out of reach of children and pets to prevent accidents. Swallowing and choking hazards.
  • Do not use the product in an environment that requires your special attention (e.g. in traffic).

Preventing damage to the product and malfunctions

  • Always keep the product dry and do not expose it to extreme temperatures (hairdryer, heater, extended exposure to sunlight, etc.) to avoid corrosion or deformation.
  • Do not place your headphones on a glass dummy head, chair armrest or similar objects for long periods as this can widen the headband and reduce the contact pressure of the headphones.
  • Use only attachments/accessories/spare parts supplied or recommended by Sennheiser.
  • Clean the product only with a soft, dry cloth.
Intended use/Liability

These open, dynamic headphones have been designed for home use with high-quality audio systems. It is considered improper use when the product is used for any application not named in the corresponding product documentation. Sennheiser does not accept liability for damage arising from the abuse or misuse of this product and its attachments/accessories. Before putting the product into operation, please observe the respective country-specific regulations.

Package contents

  • HD 660S open, dynamic headphones
  • connection cable with 1/4″ (6.35 mm) stereo
  • jack plug (connected ex-works), unbalanced 1 connection cable with 4.4 mm stereo jack plug, balanced.
  • stereo jack adapter (1/4″ (6.35 mm) to 3.5 mm) 1 instruction manual
  • storage box

Your HD 660S

The HD 660S retains all the virtues of its legendary predecessor, the HD 650, but also represents a decisive step forward technology-wise. Thanks to advanced simulation possibilities, our engineers were able to further optimize the magnet system and the shape of the diaphragm.  In terms of sound, the HD 660S sets a new benchmark in its class and masters the balancing act between perfect control and fascinating musicality in a playful way.

A: Connecting the headphones
  • SENNHEISER High-definition headphones fig 1Select the suitable connection cable and, if necessary, an adapter for your audio source to which you want to connect the headphones, and change the connection cable as described in section C:
  • 1/4″ (6.35 mm) stereo jack plug, unbalanced (can also be connected to a 3.5 mm stereo jack socket by using the supplied adapter)
  • 4.4 mm stereo jack plug, balanced
  • XLR-4, balanced (Sennheiser CH 650 S, optional accessory) Connect the headphones to your audio source.

B: Putting on the headphones and using them

  • SENNHEISER High-definition headphones fig 2Put on your headphones and then pull the ear cups down until they rest comfortably over the ears. Make sure you wear them the right way round by observing the “R” (right) and “L” (left) markings on the ear cup bands.
  • For optimum sound quality, ensure that the ear cups are not covered.

C: Changing the connection cable

  • SENNHEISER High-definition headphones fig 3Make sure the “R” (right) and “L” (left) markings on the connectors match the markings on the ear cups. The marking on the connectors must point outward.
  • Insert the connector until it locks into place with an audible click.

D: Replacing the ear pads

SENNHEISER High-definition headphones fig 4

For reasons of hygiene, you should replace the ear pads from time to time. Spare parts are available from your Sennheiser partner. To find a Sennheiser partner in your country, search at

  • Grasp behind the ear pads and pull them up and away from the ear cups.
  • Place the new ear pads onto the ear cups and attach the ear pads by pressing firmly around them.
  • The headband padding can be replaced by the Sennheiser repair service. Please contact your Sennheiser partner.

E: Cleaning and storing the headphones

  • SENNHEISER High-definition headphones fig 5Clean the product only with a dry and soft cloth.
  • Store the product in a clean, dust-free place, e.g. in its storage box.


  • Transducer principle: dynamic
  • Frequency response: 9 to 41,500 Hz (–10 dB)
  • Frequency characteristic: diffuse field equalized
  • Ear coupling: circum-aural, open
  • Contact pressure: approx. 6.0 N ± 1.0 N
  • Nominal impedance: 150 Ω
  • Sound pressure level at 1 kHz: 104 dB at 1 VRMS
  • Long-term input power: max. 500 MW as per EN 60-268-7
  • THD: ≤ 0.04% (1 kHz, 100 dB)
  • Cable: oxygen-free copper cable (OFC), 3 m
  • Connector (see pin assignment on inside cover page): stereo jack plug, gold-plated 1/4″ (6.35 mm), unbalanced, 3-pin 4.4 mm, balanced, 5-pin
  • Weight: approx. 260 g (without cable)
  • The maximum value of the static magnetic field at the surface: 2.5 MT
  • Operating temperature: 10 °C to +55°C

Manufacturer declarations

Sennheiser electronic GmbH & Co. KG gives a warranty of 24 months on this product. For the current warranty conditions, please visit our website at or contact your Sennheiser partner. For AUSTRALIA and NEW ZEALAND, ONLY Sennheiser Australia Pty Ltd provides a warranty of 24 months on these products. For the current warranty conditions, visit the Sennheiser website:

  • Australia:
  • New Zealand:
    Sennheiser goods come with guarantees that cannot be excluded under Australian and New Zealand Consumer law. This warranty is in addition to other rights or remedies under law. Nothing in this warranty excludes, limits or modifies any remedy available to be consumer which is granted by law. To make a claim under this contract, raise a case via the Sennheiser website:
  • Australia:
  • New Zealand:
    All expenses of claiming the warranty will be borne by the person making the claim. Sennheiser international warranty is provided by:
    Sennheiser Australia Pty Ltd (ABN 68 165 388 312) Level 14, Tower A Zenith Buil-ding, 821 Pacific Highway, Chatswood NSW 2067, Australia.

In compliance with the following requirements

EU declaration of conformity

RoHS Directive (2011/65/EU) The full text of the EU declaration of conformity is available at the following internet address:

UK declaration of conformity

  • RoHS Regulations (2012)

Notes on disposal

  • EU: WEEE Directive (2012/19/EU)
  • UK: WEEE Regulations (2013)

The symbol of the crossed-out wheeled bin on the product, the battery/rechargeable battery (if applicable) and/or the packaging indicates that these products must not be disposed of with normal household waste, but must be disposed of separately at the end of their operational lifetime. For packaging disposal, please observe the legal regulations on waste segregation applicable in your country.

The separate collection of waste electrical and electronic equipment, batteries/rechargeable batteries (if applicable) and packaging is used to promote the reuse and recycling and to prevent negative effects caused by e.g. potentially hazardous substances contained in these products. Herewith you make an important contribution to the protection of the environment and public health.




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