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SENNHEISER CX Plus Wireless Earbuds Manual

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SENNHEISER CX Plus Wireless Earbuds Manual

SENNHEISER CX Plus Wireless Earbuds Product image

Important safety instructions

  • Read this instruction manual carefully and completely before using the product.
  • Always include this instruction manual when passing the product on to third parties.
  • Do not use the product if it is obviously defective or makes loud, unusual (whistling or beeping) noise.
  • Only use the product in environments where Bluetooth wireless transmission is permitted.

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. Sennheiser headphones sound exceptionally good at low and medium volume levels.
  • Do not insert the earphones too deep into your ears and never insert them without ear adapters. Always remove the earphones slowly and carefully from your ears.
  • The product generates stronger permanent magnetic fields that could cause interference with cardiac pace- makers, implanted defibrillators (ICDs) and other implants. Always maintain a distance of at least 3.94″/10 cm between the product component containing the magnet (earbuds and charging case) and the cardiac pacemaker, implanted defibrillator, or other implant.
  • Keep the product, accessories and packaging parts out of reach of children and pets to prevent accidents. Swallowing and choking hazard.
  • Do not use the product in an environment that requires your special attention (e.g. in traffic). Especially the product’s active noise cancellation can make ambient noise inaudible or drastically change the perception of acoustic warning signals.

If abused or misused, rechargeable batteries may leak. In extreme cases, they may even present a risk of:

  • explosion,
  • fire development,
  • heat generation,
  • smoke or gas development.

Package contents

SENNHEISER CX Plus Wireless Earbuds Fig 1

Online you can find:

Product overview

Charging case

SENNHEISER CX Plus Wireless Earbuds Fig 2

  1. LED displays the charging process/charge status of the rechargeable battery of the charging case or of the earbuds (when inserted into the charging case).
  2. Input for USB-C connector for charging the rechargeable batteries
  3. Built-in rechargeable battery for charging the earbuds on the go
  4. Type plate
  5. Charging compartment for the left earbud L
  6. Magnetic holders
  7. Charging compartment for the right earbud R
  8. Charging contacts
  9. Touch control panel
  10. Changeable silicone ear adapters
  11. Left earbud L
  12. Status LED
  13. Infra-red carrying senor
  14. Magnetic holders
  15. Charging contacts
  16. Microphones for the active noise cancellation ANC, for the perception of ambient noise (“Transparent Hearing”) and for phone calls
  17. Right earbud R
  18. Built-in rechargeable battery

Getting started

  • Waking up the earbuds and the charging case and charging the rechargeable batteries.
  • SENNHEISER CX Plus Wireless Earbuds Fig 3Upon delivery, the rechargeable batteries of the earbuds and the charging case are in sleep mode and have to be woken up by connecting them to a power source once.
  • Insert the earbuds into the charging case.
  • Connect the USB-C cable to the charging case and to a USB power source (> 14). The earbuds and the charging case are woken up and the rechargeable batteries are being charged. The earbuds are now ready for use.

Using the earbuds

Information on the rechargeable battery, the charging process and the first use The earbuds and the charging case each have a built-in rechargeable battery. The charging case allows you to store the earbuds safely at all times while they are being charged.



Charging case WITH earbuds insertedCharging case WITHOUT earbuds inserted
pulses yellow… earbuds and charging case are being charged… charging case is being charged
lights up green… earbuds and charging case are fully charged… charging case is fully charged




flashes red

… a charging error/ battery error has been detected in at least one earbud (> 33)… a charging error/ battery error has been detected in the charging case (> 33)

If the LED does not light up:

  • Clean the contacts on the earbuds and in the charging case (> 32).
  • Charge the rechargeable batteries of the earbuds and the charging case (at least 30 minutes) until the LED lights up again.

Care and maintenance of the earbuds/charging case

Liquids can damage the electronics of the product. Liquids entering the housing of the product can cause a short-circuit and damage the electronics.

  • SENNHEISER CX Plus Wireless Earbuds Fig 4Keep all liquids far away from the product.
  • Do not use any solvents or cleansing agents.
  • Only clean the charging case with a soft, dry cloth.
  • Clean the earbuds with a slightly damp cloth.
  • You can clean the silicone ear adapters under lukewarm running water. Let the ear adapters air dry at room temperature for at least 12 hours before re-attaching them to the earbuds.
  • Clean the charging contacts on the earbuds and in the charging case from time to time using e.g. a cotton swab.

FAQ/If a problem occurs …

Current list of frequently asked questions (FAQ) Visit the CX Plus True Wireless product page at There you will find a current list of frequently asked questions (FAQ) and suggested solutions.

Your question has not been answered or the problem persists?

If a problem occurs that is not listed in the FAQ section or if the problem cannot be solved with the proposed solutions, please contact your Sennheiser partner for assistance. To find a Sennheiser partner in your country, search at

Leaving the Bluetooth transmission range

Wireless calling and streaming are only possible in the Bluetooth transmission range of your smartphone. The transmission range largely depends on environmental conditions such as wall thickness, wall composition etc. With a free line of sight, the transmission range of most smartphones and Bluetooth devices is up to 10 meters.


CX Plus True Wireless

Wearing styleTrue Wireless stereo earbuds
Ear couplingear-canal
Frequency response5 Hz to 21 kHz
Transducer principledynamic
Transducer size7 mm
Sound pressure level (SPL)114 dB (1 kHz/0 dBs)
THD (1 kHz, 94 dB SPL)≤ 0.08 % (1 kHz, 94 dB)
Noise cancellationANC technology with one pick-up microphone
Microphone principleMEMS
Microphone frequency response100 Hz to 10 kHz
Microphone pick-up pattern (speech and ANC)2-microphone beamforming array for active noise cancellation per earbud
Power supplybuilt-in lithium rechargeable batteries,

3.7 V

earbuds: 55 mash

charging case: 400 – 420 mash

USB charging via USB-C socket of the charging case: 5 V    , 600 mA

Operating time8 hrs. with rechargeable battery of the earbud

24 hrs. with rechargeable battery of the charging case

(test conditions: iPhone within 1 m distance, Bluetooth AAC codec, volume level 50 %, Transparent Hearing off, ANC off, no EQ settings)

Charging time of rechargeable batteriesapprox. 1.5 hours for full charge approx. 10 minutes for 1 hour of music playback
Temperature rangeoperation: 0 to +40°C

storage: –20 to +60°C

Relative humidityoperation: 10 to 80 %, non condensing

storage: 10 to 90 %

Magnetic field strengthearbuds: 0.7 MT charging case: 39 MT
Ingress protection of the earbudssplash proof (IPX4)
Weightearbuds: approx. 6 g each charging case: approx. 35 g

Both earbuds and charging case: 47 g



VersionBluetooth 5.2 compatible, class 1
Transmission frequency2,402 MHz to 2,480 MHz
ModulationGFSK, π/4 DQPSK, 8DPSK
ProfilesHFP, AVRCP, A2DP
Output power10 maw (max)
Codecapt®, apt adaptive®, AAC, SBC
Device nameCX Plus True Wireless


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.

In compliance with the following requirements

  • General Product Safety Directive (2001/95/EC)
  • Compliant to Sound Pressure Limits according to country specific requirement.



SENNHEISER CX Plus Wireless Earbuds PDF

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