Sennheiser MOMENTUM True Wireless Instruction Manual

MOMENTUM True Wireless
True wireless stereo earphones
M3IETW (M3IETW L, M3IETW R, M3IETW C)
Instruction manual
Use the search function, the navigation (left) or the following links:
Start
“Product overview”
“Getting started”
“Using the earphones”
“FAQ/If a problem occurs ...”
“Specifications”
Sennheiser electronic GmbH & Co. KG
Am Labor 1
30900 Wedemark
Germany
www.sennheiser.com
Version: 08/18 A01
Important safety instructions
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 an obviously defective product.
▷ 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 pacemakers, 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 or when performing skilled jobs).
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.
▷ Use only attachments/accessories/spare parts supplied or
recommended by Sennheiser.
▷ Clean the product only with a soft, dry cloth.
Safety instructions for Lithium rechargeable batteries
WARNING
If abused or misused, the rechargeable batteries may leak.
In extreme cases, they may even present a risk of
• explosion,
• fire development,
• heat generation,
• smoke or gas development.
2 | MOMENTUM True Wireless
Important safety instructions
Only use rechargeable batteries and chargers
recommended by Sennheiser.
Charge products with built-in rechargeable batteries at
ambient temperatures between 10 and 40°C/50 and
104°F.
Do not heat above 60 °C/140°F, e.g. do not expose to
sunlight or throw into fire.
When not using the product for extended periods of
time, charge its built-in rechargeable battery regularly
(about every 3 months).
Switch rechargeable battery-powered products off after
use.
Dispose of defective products with built-in rechargeable
batteries at special collection points or return them to
your specialist dealer.
Notes on data collection and processing and on firmware updates
This product stores individual settings such as the volume, the
sound profiles and the Bluetooth addresses of paired devices. This
data is required for the operation of the product and is not transferred to Sennheiser or companies commissioned by Sennheiser and is
not processed.
Using the “Sennheiser Smart Control” app, you can update the firmware of the product for free via an Internet connection. If the device
on which the app is installed is connected to the Internet, the following data is automatically transferred to and processed by Sennheiser servers in order to provide and transfer suitable firmware
updates: MAC address, Bluetooth Low Energy UUID, Bluetooth name
of the product, firmware version of the product and version of the
app. The data will only be used as specified and will not be stored
permanently.
If you do not want this data to be transferred and processed, do not
connect to the Internet.
Intended use/Liability
These headphones have been designed as an accessory for Bluetooth compliant devices. They are intended for wireless audio communication such as music playback and phone calls via Bluetooth
wireless technology.
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 improper use or misuse of this product and its attachments/accessories.
Sennheiser is not liable for damages to USB devices that are not consistent with the USB specifications. Sennheiser is not liable for
damages resulting from the loss of connection due to flat or overaged rechargeable batteries or exceeding the Bluetooth transmission
range.
Before putting into operation, please observe the respective country-specific regulations.
MOMENTUM True Wireless | 3
Package contents
Package contents
Earbud R for right ear (M3IETW R) and 
earbud L for left ear (M3IETW L)
Charging case with built-in rechargeable battery for
the earbuds (M3IETW C)
USB charging cable with USB-C and USB-A 
connector, approx. 0.25 m
Silicone ear adapters (size XS, S, M (pre-mounted to
the earphones) and L
Quick guide
Safety guide
Online you can find:
• this detailed instruction manual and additional information
(www.sennheiser.com/download)
• the Sennheiser Smart Control app for configuring the headphones and for additional functions 
(www.sennheiser.com/device-control-app)
A list of accessories can be found on the MOMENTUM True
Wireless product page at www.sennheiser.com. Contact your
local Sennheiser partner: www.sennheiser.com > “Service &
Support”.
4 | MOMENTUM True Wireless
Product overview
Product overview
Charging case
M3IETW C
7
6
8
9
1 2 3 4 5
7
LED
displays the charging process/charge status of the
rechargeable battery of the charge case or of the earbuds
(when inserted into the charging case)
Input for USB-C connector
for charging the rechargeable batteries
LED button
activates the LED display for 5 seconds
Built-in rechargeable battery for charging the earbuds on
the go
Type plate
Charging compartment for the left earbud L
Magnetic holders
Charging compartment for the right earbud R
Charging contacts
MOMENTUM True Wireless | 5
Product overview
Earbuds
M3IETW L and M3IETW R
M3IETW L
M3IETW R
B
A
G
C
A
C
L
R
0
0
D
E
D
D
E
H
D
H
F
F
F
Touch control panel
Changeable silicone ear adapters
Left earbud L (slave earbud, receives signals from the right
earbud)
Status LED
Magnetic holders
Charging contacts
Microphones for the perception of ambient noise
(“Transparent Hearing”) and for phone calls
Right earbud R (master earbud, controls the Bluetooth
connection to the smartphone and to the left earbud)
Built-in rechargeable battery
Overview of the LED indications of the
charging case
2
When a USB cable is connected, the LED of the charging case permanently displays the charging process:
6 | MOMENTUM True Wireless
Product overview
Charging case
Charging case WITH
WITHOUT earbuds
earbuds inserted
inserted
LED
pulses
yellow
... earbuds and char... charging case is
ging case are being
being charged
charged
lights up
green
... earbuds and char... charging case is
ging case are fully
fully charged
charged
flashes
red
... a charging error/
battery error has
been detected in at
least one earbud 
(> 26)
... a charging error/
battery error has
been detected in the
charging case (> 26)
2
Press
1x
If you press the LED button and no USB cable is connected, the LED
of the charging case displays the battery charge status or the charging process of the earbuds for 5 seconds:
Charging case
Charging case WITH
WITHOUT earbuds
earbuds inserted
inserted
LED
... charging case is
charged between
50-100 %
lights up
green
... earbuds are fully
charged
pulses
yellow
... earbuds are being
charged via the
–
rechargeable battery of the charging
case
lights up
yellow
... rechargeable battery of the charging ... charging case is
case is empty and
charged less than 
the earbuds are not 50 %
fully charged
lights up
red
... rechargeable bat... rechargeable batteries of the earbuds
tery of the charging
and the charging
case is empty
case are empty
flashes
red
... a charging error/
battery error has
been detected in at
least one earbud 
(> 26)
... a charging error/
battery error has
been detected in the
charging case (> 26)
MOMENTUM True Wireless | 7
Product overview
If the LED does not light up, the rechargeable battery is deep
discharged. Charge the rechargeable battery until the LED
lights up again (> 12).
Overview of the LED indications of the
earbuds
LED
Meaning; the earbud ...
flashes red-blue
... is in Bluetooth pairing mode
for approx. 1 min
3x
flashes blue 3
times
... Bluetooth pairing successful
3x
flashes red 3
times
... Bluetooth pairing failed
lights up blue
... is connected to a device via Bluetooth
(master earbud (R) is connected to
the smartphone, slave earbud (L) is
connected to the master earbud (R))
lights up red
... is not connected to a device via
Bluetooth or the connection has
been lost
(master earbud (R) is not connected
to a smartphone, slave earbud (L) is
not connected to the master earbud
(R))
flashes red
quickly
... rechargeable battery is almost
empty
flashes red
slowly
... system error. Perform a restart (>
28).
When you insert the earbuds into your ears, the LEDs of the
earbuds automatically go off after approx. 5 seconds.
8 | MOMENTUM True Wireless
Product overview
Notes on voice prompts
The earphones output voice prompts for the following functions.
Using the Smart Control app, you can change the language of the
voice prompts, choose between voice prompts and beep sounds, or
deactivate the status messages with a few exceptions (e.g. rechargeable battery is empty).
Voice prompt
Meaning/earbuds...
“Power on”
... are switched on
“Power off”
... switch off
“Connected”
... connected via Bluetooth
“No connection”
... not connected via Bluetooth
“Pairing”
... is in Bluetooth pairing mode
“Pairing cancelled”
... Bluetooth pairing cancelled
“Pairing successful”
... Bluetooth pairing successful
“Pairing failed”
... Bluetooth pairing failed
“Recharge headset”
... rechargeable battery almost
empty – recharge the battery
“Call rejected”
... incoming call rejected
“Call ended”
... call ended
“Volume min”
... volume set to minimum
“Volume max”
... volume set to maximum
MOMENTUM True Wireless | 9
Getting started
Getting started
1. Waking up the earphones and the charging
case and charging the rechargeable batteries
Upon delivery, the rechargeable batteries of the earphones and the
charging case are in sleep mode and have to be woken up by connecting them to a power source once.
▷ Insert the earphones into the charging case.
▷ Connect the USB-C cable to the charging case and to a USB
power source (> 12).
The earphones and the charging case are woken up and the
rechargeable batteries are being charged. The earphones are
now ready for use.
2. Installing the Smart Control app on your
smartphone
ON
The Sennheiser Smart Control app allows you to use all functions
and settings of the earphones and to e.g. adjust the sound to your
liking using the equalizer (> 15).
10 | MOMENTUM True Wireless
Getting started
3. Connecting the earphones to a Bluetooth
device
Connect the earphones to your smartphone via Bluetooth (> 14).
4. Selecting suitable ear adapters for optimum
fit of the earbuds
L
M
S
XS
The perceived sound quality and bass performance of the earphones
depends to a large extent on the correct fit of the earbuds in the ear.
▷ Test which ear adapter size gives you the best sound quality and
the best wearing comfort.
▷ You can choose between 4 different ear adapters in size XS, S, M
and L (> 16).
1
Left
Right
L
R
L
R
▷ Insert the right earbud into your right ear and the left earbud into
your left ear.
▷ Insert the earbuds at a slight angle into the ears and twist them
slightly into the ear canal so that they sit comfortably and snugly
in the ear canal.
MOMENTUM True Wireless | 11
Using the earphones
Using the earphones
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 your earphones safely
at all times while they are being charged.
Upon delivery, the rechargeable batteries of the earphones and the
charging case are in sleep mode and have to be woken up by connecting them once to a power source. Sennheiser recommends charging
the earphones and the charging case for a complete charging cycle
without interruption before using for the first time.
A complete charging cycle of the charging case and the earphones
takes about 1.5 hours.
Sennheiser recommends using the supplied USB cable and a compatible standard USB power supply for charging the headphones.
When a USB cable connected to a power source is also connected to
the charging case, the rechargeable battery of the charging case is
being charged. When the earbuds are inserted into the charging box,
their rechargeable batteries are being charged at the same time. The
LED of the charging case displays the charge status (> 6).
When the battery charge drops to a critical level, a voice prompt asks
you to recharge the earphones (“Recharge headset”).
The charge status of the rechargeable battery of the charging case
is displayed by the LED on the charging case (> 6).
Charging the rechargeable battery of the
earbuds and the charging case
1
L
R
2
USB-C
3
USB-A
1. Open the charging case by overcoming a slight magnetic
resistance and insert the left earbud into the left charging compartment and the right earbud into the right charging compartment.
The earbuds are magnetically pulled into the charging compartments.
2. Connect the USB-C connector of the USB cable to the USB-C
socket of the charging case.
12 | MOMENTUM True Wireless
Using the earphones
3. Connect the USB-A connector to a corresponding socket of a USB
power source (to be ordered separately). Make sure that the USB
power source is connected to the power supply system.
The rechargeable batteries of the earphones and the charging
case are being charged.
If no earphones are inserted into the charging case, only the
rechargeable battery of the charging case is being charged.
The LED of the charging case displays the charge status:
Charging case
Charging case WITH
WITHOUT earbuds
earbuds inserted
inserted
LED
pulses 
yellow
... earbuds and char... charging case is
ging case are being
being charged
charged
lights up
green
... earbuds and char... charging case is
ging case are fully
fully charged
charged
flashes
red
... a charging error/
battery error has
been detected in at
least one earbud (>
26)
... a charging error/
battery error has
been detected in the
charging case (> 26)
Connecting the earphones to a Bluetooth
device
To be able to use the Bluetooth wireless connection, you must register both devices (earphones and e.g. smartphone) via the device settings of your smartphone. This process is called pairing.
If operation differs from the steps mentioned, also refer to the instruction manual of the Bluetooth device you are using.
If you switch the earphones on for the first time after initial
charging, they automatically go into pairing mode.
Information on the Bluetooth wireless
connection
The earphones are compatible with Bluetooth 5.0.
If your audio source supports one of the following high-resolution
audio encoding methods, music is automatically played in high audio
quality: aptX, aptX® LL or AAC. Otherwise the headphones will play
your music in normal audio quality (SBC).
Paired devices establish the Bluetooth wireless connection immediately after switch-on and are ready for use.
When you switch the earphones on, they automatically try to
connect to the last connected Bluetooth device. The earphones can
save the connection profiles of up to eight Bluetooth devices with
which they have been paired.
MOMENTUM True Wireless | 13
Using the earphones
If you pair the earphones with the ninth Bluetooth device, the saved
connection profile of the least used Bluetooth device will be overwritten. If you want to re-establish a connection with the overwritten
Bluetooth device, you have to pair the earphones again.
paired +
connected
R
paired
Pairing the earphones with a Bluetooth
device
1
2
“Pairing“
max. 50 cm
Hold
5s
3
4
“Pairing
successful“
ON
MOMENTUM
TW
ON
ON
ON
1. Take both earbuds out of the charging case and insert them into
your ears (> 16). The distance between the earbuds and the Bluetooth device should not exceed 50 cm.
2. Simultaneously touch and hold the right and the left touch control
panel for 5 seconds until you hear the voice prompt “Pairing” and
a beep.
The LEDs of the earbuds flash blue and red. The earbuds are in
pairing mode.
3. Activate Bluetooth on your Bluetooth device.
4. Via the menu of your Bluetooth device, start the search for new
Bluetooth devices.
All active Bluetooth devices in the proximity of your smartphone
are displayed.
From the list of found Bluetooth devices, select “MOMENTUM
TW”. If necessary, enter the default pin code “0000”.
If pairing was successful, you hear the voice prompt “Pairing successful” and the LEDs of the earbuds flash blue 3 times.
14 | MOMENTUM True Wireless
Using the earphones
If no connection is established within 1 minute, pairing mode is
terminated and the earbuds switch to idle mode. If necessary,
repeat the pairing procedure.
Disconnecting the earphones from a
Bluetooth device
▷ Via the menu of your Bluetooth device, disconnect the connection
to the earphones.
The earphones are disconnected from the Bluetooth device. The
earphones then search for other paired devices. If no device is
found, you hear the voice prompt “No connection”. The earphones
go to idle mode.
If you want to clear the Bluetooth pairing list of the earphones,
reset the earphones to the factory default settings (> 29).
Installing the Smart Control app
To make full use of all the settings and functions of the earphones,
you need to have the free Sennheiser Smart Control app installed on
your smartphone.
Download the app from the App Store or Google Play and install it on
your smartphone. Alternatively, you can use your smartphone to
scan the following QR code or to call up the following Internet site:
www.sennheiser.com/device-control-app
▷ Connect your smartphone to the earphones using Bluetooth (>
13).
▷ Start the Smart Control app.
The Smart Control app recognizes the earphones and activates
all available settings and functions.
MOMENTUM True Wireless | 15
Using the earphones
Selecting suitable ear adapters for
optimum fit of the earbuds
L
M
S
XS
Click
The perceived sound quality and bass performance of the earphones
depends to a large extent on the correct fit of the earbuds in the ear.
▷ Pull the ear adapter away from the in-ear sound tunnel.
▷ Mount the new ear adapter to the in-ear sound tunnel. Ensure that
it locks into place.
▷ Test which ear adapter size gives you the best sound quality and
the best wearing comfort.
You can choose between 4 different ear adapters in size XS, S, M
and L. The ear adapters must fit snugly in the ear canal and completely seal your ears.
Inserting the earbuds into the ears
1
Left
Right
L
R
L
R
▷ Insert the right earbud into your right ear and the left earbud into
your left ear.
▷ Insert the earbuds at a slight angle into the ears and twist them
slightly into the ear canal so that they sit comfortably and snugly
in the ear canal (> 16).
You can use the right earbud alone without using the left earbud. The left earbud, however, cannot be used alone.
The Smart Pause function automatically stops music playback
if you remove an earbud from your ear (> 20).
16 | MOMENTUM True Wireless
Using the earphones
Switching the earbuds on
WARNING
Danger of hearing damage due to high volumes!
Listening at high volume levels can lead to permanent
hearing defects.
▷ Before putting your headphones on, adjust the volume
to a low level (> 18).
▷ Do not continuously expose yourself to high volume
levels.
On
“Power on“
“Connected“
▷ Take both earbuds out of the charging case and insert them into
your ears (> 16).
If a paired Bluetooth device is within the transmission range, you
hear the voice prompts “Power On” and “Connected”. The LEDs
of the earbuds light up blue.
The earbuds automatically switch to idle mode if they do not
find a paired Bluetooth device within 15 minutes or if they are
inactive for approx. 60 minutes (connected via Bluetooth but no
audio playback). You can wake up the earbuds from idle mode
by touching their touch control panels once or by briefly inserting them into the charging case.
Switching the earbuds off
L
R
Off
The earbuds do not have to be switched off explicitly.
▷ Insert the earbuds into the charging case to switch them off.
As soon as the earbuds are inserted into the charging case, they
switch off and are being charged (> 12).
MOMENTUM True Wireless | 17
Using the earphones
The earbuds automatically switch to idle mode if they do not
find a paired Bluetooth device within 15 minutes or if they are
inactive for approx. 60 minutes (connected via Bluetooth but no
audio playback). You can wake up the earbuds from idle mode
by touching their touch control panels once or by briefly inserting them into the charging case.
If you remove an earbud from your ear, music playback is paused. This Smart Pause function can be deactivated (> 20).
Adjusting the volume
WARNING
Danger of hearing damage due to high volumes!
Listening at high volume levels can lead to permanent
hearing defects.
▷ Before putting the headphones on and before toggling
between the audio sources, adjust the volume on the
headphones to a low level.
▷ Do not continuously expose yourself to high volume
levels.
Hold
Hold
R
L
To increase the volume:
▷ Touch and hold the touch control panel of the right earbud until
the volume is increased.
To reduce the volume:
▷ Touch and hold the touch control panel of the left earbud until the
volume is reduced.
When the minimum or maximum volume is reached, you hear the
voice prompt “Volume max” or “Volume min”.
You can also adjust the volume using the connected Bluetooth
device or the Smart Control app.
18 | MOMENTUM True Wireless
Using the earphones
Listening of ambient noise or
conversations - activating/deactivating
the Transparent Hearing function
With Transparent Hearing activated, you can hear ambient sounds or
communicate without having to remove the earbuds from your ears.
This allows you to hear e.g. announcements in the train or airplane or
to have short conversations.
ON/OFF
2x
R
▷ Tap the touch control panel of the right earbud 2 times.
The Transparent Hearing mode set in the Smart Control app is
activated. You can hear ambient sounds without having to
remove the earbuds from your ears.
To deactivate Transparent Hearing:
▷ Tap the touch control panel of the right earbud once.
Adjusting the Transparent Hearing
function
To be able to fully use Transparent Hearing, you require the Smart
Control app (> 15).
▷ Select the desired Transparent Hearing function in the Smart
Control app:
Transparent Hearing
Description
“Keep music playing and
mix with ambient sound”
The audio playback (e.g. music)
continues and is mixed with ambient
sounds.
“No music playback, only The audio playback (e.g. music) is
ambient sound”
muted and you hear only ambient
sounds.
Using the voice assistant/voice dialing
▷ Tap the touch control panel of the right earbud once.
The available voice assistant of your smartphone is activated
(*depending on the system or app used on your smartphone: Siri,
Google Assistant, Baidu, ...).
▷ Ask the voice assistant your question or make a request.
To disable the voice assistant/voice dialing:
MOMENTUM True Wireless | 19
Using the earphones
▷ Tap the touch control panel of the right or left earbud once.
ON/OFF
1x
Siri, Google Assistant,
Baidu, ...*
R
Using the Smart Pause function
The earbuds automatically detect whether they are worn in the ear
or removed from the ear.
Music playback pauses when you remove an earbud from the ear and
continues when you insert it again.
You can also deactivate the function via the Smart Control app.
The right earbud (master earbud) can be used alone. The left
earbud (slave earbud) cannot be used alone because it requires
the right earbud for Bluetooth transmission.
Controlling the music playback
The music playback functions are only available when the earphones
and the device are connected via Bluetooth. Some smartphones or
music players may not support all functions.
The left earbud allows you to control music playback.
L
Playing/pausing music
▷ Tap the touch control panel of the left earbud once.
Left touch control panel
Tap once
Function
Plays or pauses music
Playing the next track
▷ Tap the touch control panel of the left earbud 2 times.
20 | MOMENTUM True Wireless
Using the earphones
Left touch control panel
Tap 2 times
Function
Plays the next track in the playlist
Playing the previous track
▷ Tap the touch control panel of the left earbud 3 times.
Left touch control panel
Tap 3 times
Function
Plays the previous track in the playlist
Making calls using the earphones
The call functions are only available when the earphones and the
smartphone are connected via Bluetooth. Some smartphones may
not support all functions.
The right earbud allows you to control the call functions.
R
Making a call
▷ Dial the desired number on your smartphone.
If your smartphone does not automatically transfer the call to the
earphones, select “MOMENTUM TW” as the audio source on your
smartphone (see the instruction manual of your smartphone if
necessary).
Accepting/rejecting/ending a call
If your earphones are connected to a smartphone and you receive a
call, you hear a ring tone in the earphones.
If you are playing music when you receive a call, the music pauses
until you end the call.
Right touch control panel
Function
Tap once
Accepts a call
Tap once
Ends a call
Voice prompt “Call ended”
MOMENTUM True Wireless | 21
Using the earphones
Right touch control panel
Function
Tap 2 times
Rejects a call
Voice prompt “Call rejected”
Tap once
Accepts an incoming call and ends
the active call
Tap 2 times
Rejects an incoming call and continues the active call
Displaying the battery charge status
If the earphones are connected to your Bluetooth device, the battery
charge status can be displayed on the screen of your smartphone or
device (depending on the device and operating system used).
The Sennheiser Smart Control app also displays the charge status of
the earphones' rechargeable batteries.
Displaying the battery charge status using the charging case
Press
Press
1x
1x
If no USB cable is connected to the charging case:
▷ Press the LED button of the charging case.
The LED of the charging case displays the battery charge status
for 5 seconds:
Charging case
Charging case WITH
WITHOUT earbuds
earbuds inserted
inserted
LED
22 | MOMENTUM True Wireless
... charging case is
charged between
50-100 %
lights up
green
... earbuds are fully
charged
pulses 
yellow
... earbuds are being
charged via the
–
rechargeable battery of the charging
case
lights up
yellow
... rechargeable battery of the charging ... charging case is
case is empty and
charged less than 
the earbuds are not 50 %
fully charged
Using the earphones
Charging case
Charging case WITH
WITHOUT earbuds
earbuds inserted
inserted
LED
lights up
red
... rechargeable bat... rechargeable batteries of the earbuds
tery of the charging
and the charging
case is empty
case are empty
flashes
red
... a charging error/
battery error has
been detected in at
least one earbud 
(> 26)
... a charging error/
battery error has
been detected in the
charging case (> 26)
Adjusting sound effects/the equalizer
To be able to use the sound effects/equalizer, you require the Smart
Control app (> 15).
▷ In the Smart Control app, select the desired sound effects via the
equalizer.
The sound effects are stored in the earphones. These sound settings are active even without using the Smart Control app, i.e.
when you are using another Bluetooth device.
Setting the voice prompts/beep sounds
To be able to set the voice prompts and beep sounds, you require the
Smart Control app (> 15).
You can change the language of the voice prompts, choose between
voice prompts and beep sounds, or deactivate the status messages
with a few exceptions (e.g. rechargeable battery is empty).
MOMENTUM True Wireless | 23
Using the earphones
Storing or transporting the earphones in
the charging case
Store the earphones in the charging case to prevent damage to the
earphones when you are not using or transporting them. The earphones are automatically charged in the charging case so you always
have the full battery life to work with.
▷ Open the charging case by overcoming a slight magnetic
resistance and insert the left earbud into the left charging compartment and the right earbud into the right charging compartment.
The earbuds are magnetically pulled into the charging compartments.
▷ Close the charging case.
L
24 | MOMENTUM True Wireless
R
Care and maintenance
Care and maintenance
CAUTION
Liquids can damage the electronics of the product!
Liquids entering the housing of the product can cause a short-circuit
and damage the electronics.
▷ Keep all liquids far away from the product.
▷ Do not use any solvents or cleansing agents.
▷ Clean the product only with a soft, dry cloth.
▷ Clean the charging contacts on the earbuds and in the charging
case from time to time using e.g. a cotton swab.
Changing the ear adapters
For reasons of hygiene, you should replace your ear adapters from
time to time. Spare ear adapters are available from your Sennheiser
partner.
1. Pull the ear adapter away from the in-ear sound tunnel.
2. Mount the new ear adapter to the in-ear sound tunnel. Ensure that
it locks into place.
L
M
S
XS
Click
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Care and maintenance
Information on the built-in rechargeable
battery
Sennheiser ensures and guarantees that the rechargeable batteries
perform at their optimum upon purchase of the product. If, upon
purchase or within the warranty period, you suspect that a rechargeable battery is obviously defective or if a charging error/battery error
is displayed (> 6), stop using the product, disconnect it from the
power supply system and immediately return the product to any
Sennheiser service partner.
Installing firmware updates
Firmware updates can be downloaded free of charge from the Internet using the Sennheiser Smart Control app.
▷ Connect your earphones to your smartphone and start the Smart
Control app (> 15).
▷ The app provides information on available firmware updates and
guides you through the installation process.
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FAQ/If a problem occurs ...
FAQ/If a problem occurs ...
The left earbud cannot be used?
Make sure that the earbud is charged (> 12) and that the earphones
are paired with your Bluetooth device and connected to it (> 14). The
left earbud can only be used when the right earbud is also used (the
right earbud controls the Bluetooth transmission). The signal transmission range between the left earbud and the right earbud is
approx. 25 cm.
The right earbud cannot be used?
Make sure that the earbud is charged (> 12) and that the earphones
are paired with your Bluetooth device and connected to it (> 14).
The earphones cannot be switched on/do not react to any touch?
Wake up the earphones from idle mode by tapping their touch control panels once (> 17).
Make sure that the earphones are charged (> 12). If this is the case,
perform a restart of the earphones (> 28).
The earphones cannot be charged?
Perform a restart of the earphones (> 28).
The operating time is decreasing?
The rechargeable batteries are exhausted. Contact your Sennheiser
service partner.
The sound occasionally drops out?
Make sure that the earphones are within the transmission range of
the Bluetooth device (> 28).
The sound is too low?
Increase the volume (> 18).
The sound of the earphones sounds misadjusted?
It might be that the sound has been adjusted using the equalizer function of the Smart Conrol app. Connect to the Smart Control app and
check the equalizer settings (> 23).
The sound is only audible on one side?
Make sure that both earbuds are charged (> 12) and that the earphones are paired with your Bluetooth device and connected to it (> 14).
Also make sure that the earbuds are inserted into your ears correctly
(> 16).
The sound is not in lip-sync with the TV/PC picture?
Make sure you are using a Bluetooth device with aptX Low Latency
(LL) to have low audio latency.
The earphones are uncomfortable?
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FAQ/If a problem occurs ...
Test the different ear adapters to find the size that suits you best and
delivers the best sound quality (> 16).
The earphones are connected via the Smart Control app, but music
playback is not possible?
If you connect the earphones only via the Smart Control app, you only
establish the connection for controlling the earphones (via Bluetooth
Low Energy). In order to enable music playback, you have to pair the
earphones with your smartphone using the smartphone's Bluetooth
menu (> 13).
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 
www.sennheiser.com > “Service & Support”.
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.
If you, and therefore the earphones, leave the Bluetooth transmission
range of the smartphone, the sound quality deteriorates increasingly
until you hear the voice prompt “No connection” and the connection
breaks down completely. If you immediately re-enter the Bluetooth
transmission range of the smartphone, the connection is automatically re-established and you hear the voice prompt “Connected”. If
this is not the case, tap the touch control panel of the earbud once.
The right earbud (master earbud) can be used alone. The left earbud
(slave earbud) cannot be used alone because it requires the right
earbud for Bluetooth transmission.
Restarting the earphones
If the function of the earphones is disturbed, perform a restart:
▷ Use the USB cable to connect the charging case to a power
source (> 12).
▷ Insert the earbuds into the charging case and, within 60 seconds,
touch and hold the right and the left touch control panel for 6
seconds.
The earphones are restarted.
Hold
6s
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FAQ/If a problem occurs ...
Resetting the earphones to the factory default settings/Reset
If the function of the earphones is disturbed and a manual restart (>
28) does not improve, reset the earphones to the factory default settings. This deletes, among other things, all pairing settings.
▷ Use the USB cable to connect the charging case to a power
source (> 12).
▷ Insert the earbuds into the charging case and, within 60 seconds,
touch and hold the right and the left touch control panel for at
least 30 seconds.
The earphones are reset to the factory default settings.
Hold
30s
You can also reset the earphones to the factory default settings
using the Smart Control app.
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Specifications
Specifications
MOMENTUM True Wireless M3IETW
Wearing style
True wireless stereo earphones
Ear coupling
ear canal
Frequency response
5 Hz to 21 kHz
Transducer principle
dynamic, closed-back
Transducer size
7 mm
Sound pressure level (SPL) 107 dB (1 kHz/1 mW)
THD (1 kHz, 94 dB SPL)
< 0.08 %
Microphone principle
MEMS
Microphone frequency
response
100 Hz to 10 kHz
Microphone sensitivity
94 dB SPL at 1 kHz
Microphone pick-up pattern 2-mic beamforming array
(speech audio)
Power supply
built-in Lithium rechargeable
batteries, 3.7 V
left earbud: 60 mAh
right earbud: 85 mAh
charging case: 600 mAh
USB charging via USB-C socket of the
charging case: 5 V
, 650 mA
Operating time
4 hrs (music playback via A2DP) with
rechargeable batteries of the
earbuds;
12 hrs with rechargeable battery of
the charging case
Charging time of
rechargeable batteries
approx. 1.5 hours
Temperature range
operation: 0 to +40°C
storage: -25 to +60°C
Relative humidity
operation: 10 to 80%, non condensing
storage: 10 to 90%
Magnetic field strength
earbuds: 1.6 mT
charging case: 130 mT
Ingress protection of the
earbuds
Weight
splash proof (IPX4)
left earbud: approx. 6 g
right earbud: approx. 7 g
charging case: approx. 57 g
Bluetooth
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Version
Bluetooth 5.0 compatible, class 1, BLE
Transmission frequency
2,402 MHz to 2,480 MHz
Modulation
GFSK, π/4 DQPSK, 8DPSK
Profiles
HSP, HFP, AVRCP, A2DP
Output power
10 mW (max)
Codec
aptX®, aptX® LL, AAC, SBC
Manufacturer Declarations
Manufacturer Declarations
Warranty
Sennheiser electronic GmbH & Co. KG gives a warranty of 24 months
on this product.
For the current warranty conditions, please visit our website at
www.sennheiser.com 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
requirements
EU declaration of conformity
• RoHS Directive (2011/65/EU)
Hereby, Sennheiser electronic GmbH & Co. KG declares that the
radio equipment type M3IETW L, M3IETW R, M3IETW C is in compliance with the Radio Equipment Directive 2014/53/EU.
The full text of the EU declaration of conformity is available at the following internet address: www.sennheiser.com/download.
Notes on disposal
• Battery Directive (2006/66/EC & 2013/56/EU)
• WEEE Directive (2012/19/EU)
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.
Further information on the recycling of theses products can be
obtained from your municipal administration, from the municipal collection points, or from your Sennheiser partner.
The separate collection of waste electrical and electronic equipment, batteries/rechargeable batteries (if applicable) and packagings 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.
Trademarks
Sennheiser is a registered trade mark of
Sennheiser electronic GmbH & Co. KG.
Apple and the Apple logo are trademarks of Apple Inc., registered in
the U.S. and other countries. App Store is a service mark of Apple Inc.
Google Play and the Google Play logo are trademarks of Google LLC.
The Bluetooth® word mark and logos are registered trademarks
owned by Bluetooth SIG, Inc. and any use of such marks by Sennheiser electronic GmbH & Co. KG is under license.
Qualcomm aptX is a product of Qualcomm Technologies International, Ltd. Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries, used with permission.
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Manufacturer Declarations
aptX is a trademark of Qualcomm Technologies International, Ltd.,
registered in the United States and other countries, used with permission.
Other product and company names mentioned in the user documentation may be the trademarks or registered trademarks of their respective holders.
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