MobiFren Sound Master MFB-NB5100 User manual

High Resolution sound with
LDAC Stereo Bluetooth headset
Sound Master MFB-NB5100
User Manual
MobiFren is made by dreaming for all the user's happiness.
It delivers premium sound via MSTS™ Tuning Technology together with lossless compression
codec Qualcomm®aptX™ & AAC codec enabling you to enjoy music with premium Hi-Fi
sound in wireless like as CD quality.

MSTSTM is a Audio Technology of MobiFren Co.,Ltd.
Qualcomm aptX is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.
Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries.
aptX is a trademark of Qualcomm
MobiFren MFB-NB5100 Features
This manual includes the following model as a series of NB5100.
Model name MFB-NB5100S
(Flex E Soul)
MFB-NB5100A
(Flex E Air)
Ear body
component
Canal type
Open type
Characteristics All-in-one type(different in ear boby design)
Premium Sound
MSTS™ Tuning Technology together with lossless compression codec Qualcomm®aptX™ & AAC codec
enables you to listen premium Hi-Fi stereo sound.
With built-in DSP chip, it enables optimal call quality by noise reduction and echo cancellation.
Supporting Android & iOS App.
You can use many kinds of useful functions like as below, if you download MobiFren_SM from the store.
※App function may be changed due to mobile phone OS update or improving or adding function.
Caller ID TTS
If you press any button of the headset on incoming call, your mobile reads you
the caller's name.
(In case of iPhone, it reads caller ID together with bell sound and you can listen via earphone too)
TTS message (SMS, Line , Whats
app or other SNS)
If there's new message of SMS or SNS, it reads you the message, together with
vibration.
Find mobile phone If you can not remember well where you placed mobile phone, it helps you to
find out your mobile phone by pressing headset button.
Hot call If you
register the number in advance that you call frequently, you can call easily
by pressing headset button.
Last Call
(Available with Android) You can call to the lastest number directly.
Present time notice By pressing headset button for 2 times consecutively, it notices you the present time.
Voice Memo
(Available with Android) It's to record the conversation by operating headset button simply during a call.
Anti Phone loss function If your mobile phone is out of ranges from the headset, it alarms you by vibration
for 1 minute to prevent the loss of your mobile phone.

Vibration on incoming call
The headset alarms you by vibration if there's incoming call.
Anti Phone loss function
If your mobile phone is out of ranges from the headset, it alarms you by vibration for 1 minute to prevent the
loss of your mobile phone.
Multi Point
Supporting Bluetooth 5.0(BDR,EDR)
Voice prompt
Supporting firmware upgrade
※Features of this product depend on your mobile phone.
This manual can have different images or contents from the purchased ones due to common
edition. This manual can be modified according to company situations.

Contents
Headset & Accessories ....................................................................................... 1
Safety Instruction................................................................................................... 1
Turn on/off the headset......................................................................................... 2
Headset charging .................................................................................................. 2
About your MobiFren MFB-NB7100 Series ............................................... 3
Button Guide ........................................................................................................... 4
Getting started with your MobiFren............................................................. 6
1. Pairing to your mobile phone ............................................................... 6
2. Multi point setting ...................................................................................... 7
3. Call...................................................................................................................... 7
4. Factory Reset ................................................................................................. 8
5. Firmware Upgrade....................................................................................... 8
6. Changing Music Mode.............................................................................. 8
7. Mobile phone Anti-loss ............................................................................ 9
8. Using Android & iOS application......................................................... 9
9. Couple listening mode(MobiShare)...................................................11
What does LED color mean?..........................................................................13
FAQ & Troubleshooting ...................................................................................14
Handle MobiFren with care ............................................................................15
Certification and safety approvals ...............................................................16
Specifications.........................................................................................................17
Warranty..................................................................................................................18

- 1 -
Headset & Accessories
MFB-NB5100
Pouch User Manual Charging cable
※The drawings and examples in manual are for better understanding to this product, so, it may be different
from the real goods. Accessories and design can be changed without prior notice.
Safety Instruction
- Road safety at all times.
- Using mobile phone while driving can distract you and increase the possibility of an accident.
- Do not use mobile phones while driving. Always drive safely and follow local laws.
Manual

- 2 -
Turn on/off the headset
< Turn on >
Press for 2 seconds.
It turns on and glitters blue LED.
< Turn off >
Press for 4 seconds.
If you give MFB button long press, the purple LED
glitters and earphone is power off.
Headset charging
※Make sure that your headset is fully charged before you use it.
- The red LED shows during charging and turns blue LED after fully charged.
- You can use it during charging.
- Charging may not work properly due to low current if you use USB hub.
- It's compatible with Android smart phone charging cable (Mirco 5pin).
MFB button

- 3 -
About your MobiFren MFB-NB5100
(1) Microphone Microphone
(2) LED Light LED guide light for headset status
(3) Micro USB charging port Charging port
(4) Volume up Volume control, Next song etc.
(5) Multi Function button Turn on/off, Answer/Reject/Convert a call, Play/Pause etc.
(6) Volume down Volume control, Previous song etc.
(7) Fixing Magnet Holding L&R earphone with magnet while not in use.
(8) Ear pad Padded material of ear pad

- 4 -
Button Guide
You can control MFB-NB5100 easily with the following 3 buttons.
MFB Volume up Volume down
Basic Button Control
Answer a call Short press
End a call Short press
Turn on headset Press for 2 seconds
(If no paired device, it moves to pairing mode automatically.)
(If there's paired device, it connects to the paired device.)
Turn off headset Press for 4 seconds
Pairing mode Press for 4 seconds at power off
End a call Short press (during call)
Reject a call Press for 1 second
Convert a call Press shortly in mobile during call
Play/Pause Short press
Siri (Voice input) Press for 1 second
Volume + Short press
Next song Press for 1 second (during play)
Camera remote control Short press
Voice for battery level Press for 1 second
Volume - Short press
Mic mute Press for 1 second (during call)
Previous song Press for 1 second (during play)
Camera remote control Short press
Voice for battery level Press for 1 second
Music Mode Change Press for 1 second (during play)
To move forward direction, press button and button
simultaneously.
To go backward direction, press button and button simultaneously.
Couple listening mode(MobiShare)
Entering couple listening mode Press for 1 second
Releasing couple listening mode Press for 1 second
Press MFB
Press Vol. up button.
Press Vol. down button.
Press + Volume or
button at the same time.
Press + at the same time
Press + at the same time

- 5 -
Operating App functions with headset
TTS caller ID or Press volume button.Press button deeply (while being ringed)
TTS (Stop during TTS) Press any button among / /
buttons
Press any button Short press for 1 time
(during message TTS)
TTS (Manual TTS play) Press (MFB) + Volume or
button at the same time. Short press for 1 time
Present time notice Press MFB buttonShort press for 2 times
Voice Memo Press MFB button 1 seconds and hold pressed and release
Hot call (Prompt call)
Press Vol. up button Short press for 2 times (at standby)
※While the sound vibrations to make a call to a specified number.
Last Call (Direct call) Press Vol. down button Short press for 2 times (at standby)
※There are basic mode and exceptional mode for Hot Call/Last Call. If you choose exceptional mode,
it works during playing music. You can set exceptional mode in app.
Find mobile phone and at the same time Press for 1 second
Available for siri and
voice talk modes
Press button, and talk mode is
on. Press for 1 second
Factory Reset
Press ➜➜➜ buttons in order , then press button

- 6 -
Getting started with your MobiFren
MFB-NB5100 series are easy to use for everyone.
※Before you use MobiFren Bluetooth earphone, you need to pair it with your mobile phone or Bluetooth
enabled device.
Step 1 : Entering into pairing mode with Bluetooth headset.
- Press button till LED is continuously on for about 4 seconds at power-off.
(You need to pair within 3 minutes.)
Step 2 : Pairing by mobile phone
➀Activate Bluetooth function in your mobile phone according to phone manual and search Flex E Air (or
Soul)and select, then, it shows "Pairing".
(Some mobile phone needs Pin code, then, enter "0000")
➁If pairing is successful, it shows that " Connected to phone and media audio" and blue LED glitters for
5 times. Now, it's ready to use.
※Pairing will be more easy with MobiFren_SM application
➀Install "MobiFren_SM" from Google play store / App store.
➁Press the first menu "Pair (Connect) headset ", then it goes to Bluetooth setting.
➂Activate Bluetooth and search headset.
➃Select "Flex E Air (or Soul)" from the searched devices, then it pairs.
※Connecting app for iPhone
To use convenient app for iPHone, you need to connect "MobiFren_SM" app after connecting headset to
iPhone.
After connecting Flex E Air (or Soul), there’s “Bluetooth connection” pop-up window after running
“MobiFren_SM” Then, connection is completed if you select “connection by pair”
(If you run app within 1 minute after connection, there’s “Bluetooth connection” pop-up window
automatically. If it passes for 1 minute, please press any button of the headset and run “MobiFren_SM”
Then, there’s pop-up message to connect.)
※Useful tip (3 ways to go Bluetooth setting)
➀Menu button, Setting, Bluetooth on wallpaper.
➁Drag down the screen and press Bluetooth icon for 1 second.
➂Run MobiFren_SM app. and select the menu " Pair (Connect) headset".
※Pairing process may be different from mobile phone makers. Please refer to mobile phone's manual.
※In case of Iphone, 2 devices with model name and model name2 are connected in bluetooth setting
( If model name is MFB-NB5100A, 2 devices are named Flex E Air and Flex E Air2).
(Pairing process may be different from mobile phone makers. Please refer to mobile phone's manual.)
1. Pairing to your mobile phone

- 7 -
※It's possible to pair up to 2 devices simultaneously.
(App related functions which are not Bluetooth basic functions like as call or listening music shall be connected
with only one device, so, we recommend to connect with one mainly used device.)
1) Setting Multi point
- Please pair MFB-NB5100 to the first device according to the pairing process.
(Refer to pairing process P.6 )
- Turn off MFB- NB5100.
- Please pair MFB- NB5100 to 2nd device according to pairing process.
- Then, turn off MFB- NB5100 and turn on again, it will be connected 2 devices.
2) To use multi point
- At the status of connecting two devices, press to answer a call if there's incoming call.
- At the status of connecting two devices, if you press then, you can listen the music for the device that
was played lately.
1) Answering a call
- Press one of these / / 3 buttons at your convenience to answer a call.
- Vibration on incoming call : There's vibration in every 2 second, if there's incoming call.
You can set ON/OFF in app.
2) Ending a call
- Press button to end a call.
3) Rejecting a call
- During call, press button for about 1 second.
4) Converting a call
- During call by mobile, press button to convert to headset
(To call by mobile again, use your mobile phone menu.)
5) Volume control
- With / button, you can control volume.
6) Microphone Mute
- During call, if you press button for about 1 second, the mic becomes mute.
- During mute, it will be released, if you press button for about 1 second.
2.Multi point setting
3. Call

- 8 -
7) Waiting a call and put a call on hold
- This feature allows you to put a call on hold during conversation and answer a waiting call.
- Give the a long press (press approximately 1 second) to put an active call on hold and answer a waiting
call.
- Give the a long press to switch between two calls.
- Just press shortly to end a call.
Press ➜➜➜buttons in order, then press button, and violet signal lights flicker and MFB-
NB7100 is initialized to the factory shipment state.
Please pair the headset again after factory reset.
The USB port can be used for charging and data communication.
1) Consumers can use the USB port only for charging purposes.
2) manufacturers and authorized service centers use part of the DATA communication for firmware modifications
and so on.
You can use 5 music modes and 1 user mode.
While playing music, if you press button and or button at the same time for 1 second, the Music
Mode will be changed in order.
MSTS™ Tuning technology together with lossless compression codec Qualcomm®aptX™ & AAC codec
enables you to enjoy not only MobiFren sound but similar sound of various kinds of famous high end
earphones and you can select it as your preference. Now you will enjoy the music with the optimum sound
quality like as CD in wireless.
4.Factory Reset
5.Firmware Upgrade
6.Changing Music Mode

- 9 -
Music Mode
Sound Effects
Each music mode can be tuned on/off the Bass Enhancement & 3D Enhancement.
※ There are several kinds of bit rate even though it's the same MP3 file. If the file source is higher bit rate(320K)
for listening, you can feel the real worth for our Bluetooth earphone. And, if the speaker is not good even
with good source, the sound quality will not be good, and if the speaker is good with inferior source, the
sound quality can't touch to the listener. The MobiFren earphone of optimized tuning supplies you high
quality sound, but, we also recommend you to use high resolution source file (320K) to enjoy touching sound.
- If your mobile phone is out of some ranges from the headset, the headset alarms you with vibration for
1 minute to prevent phone loss. Press any button to stop vibration.
For more convenient and easy use of the headset, please download "MobiFren_SM" at Google play store or
Apple App store.
(Minimum supporting specification : higher than iPhone 4S / Recommend : higher than iPhone 5)
※Detailed operation for each function shall be different between Android and iOS app.
TTS caller ID
To answer a call, press or button deeply on the headset, then the caller's name is indicated by the
speaker of the mobile phone.
Mobifren Mode : MobiFren Sound
Reference Mode : Natural sound using faithfully the original sound
Space Mode : Extraordinary sound creating a wide sense of space
Tender Mode : Sound of tone color whispering softly into ear
Enhance Mode : Sound of tone color even reproducing vividly breath
User Mode : Sound created by user
7.Mobile phone Anti-loss
8. Using Android & iOS application

- 10 -
Message TTS (SMS/ Kakao Talk/ Line / WhatsApp)
After setting Message TTS, in automatic mode, it reads you message after the setting time, and in manual
mode, you can hear message by using headset button. (When you set this function, it goes to mobile phone's
notification accesss menu automatically, then, select MobiFren_SM in notification accesss menu.)
Stop while playing TTS : TTS playing stop.
While reading TTS message, press / / button to stop playing.
Manual mode : It reads you message by pressing headset button.
Press button and or button shortly at the same time at standby.
Find mobile phone
If you can't remember well where you placed your mobile phone, press and buttons at the same time
for about 1 second to find out your mobile phone. Then, the mobile phone will ring.
Hot Call (Prompt call)
Register one frequent call number and press button shortly for 2 times. (In case of iPhone, it needs to
press Call button in your mobile.)
Last call (call to the latest number) (Android only)
Pressing button shortly two times, the latest caller is read(through earphone) while it's optional to select
the expected caller from caller lists by pressing up and down button away from the unexpected callers, and
then pressing button or deeply, the chosen caller can be called back. In driving or not seeing mobile
screen, it's available to call by the latest call lists with headset simply.
Present time notice
You can hear present time via headset if you press button for 2 times consecutively.
Voice Memo (Android only)
It's useful to record voice memo by pressing button for 1 second and releasing during a call.
You can record it by pressing the same button during a call or not.
Anti Mobile Phone loss
If your mobile phone is out of some range from the headset, the headset alarms you with vibration for 1
minute to prevent phone loss.
Available for siri and voice talk mode
In the ON state of talk mode function, voice input button is called repeatedly and continuously like as if talking
by pressing headsetbutton deeply.
To stop talking, press any buttons.

- 11 -
This function is used when two people want to listen to music on one's mobile phone. If you connect two
earphones with MobiShare function in couple listening mode, you can enjoy the same music with your earset.
Entering Couple Listening Mode
Press and hold + simultaneously while both headphones are on.
When a beep sounds and the blue LED and the red LED alternately flash, it enters into a mode to connect
the two products. Wait for a while, "tortoise" sound and the LED turns off and both products are connected.
After connecting, you can enjoy the same music on both headsets by playing music.
Releasing Couple Listening Mode
To turn off the Couple Listening mode, press and hold the + button.
The connection is released after a beep is heard.
※If the distance between the connected devices is more than 5m away while operating the couple listening
mode, the phenomenon such as sound discontinuity may occur.
※If the sound is cut off when using with a specific phone such as iPhone, it occurs because the phone gives
the streaming signal even when the music is stopped. In this case, if you disconnect the Bluetooth connection
from the slave, it will work normally. (When you are connected to Couple Listening Mode, the one that plays
music first becomes the master, and the other mobile becomes the slave.)
9. Couple listening mode(MobiShare)

- 12 -
< Available functions for Android or iOS app >
App function Android iOS
Music Mode control ○○
Battery gauge ○○
Message TTS ○
○
(Ref.) iPhone supporting SNS
shall be different from that of
Android.
Anti Mobile Phone loss ○○
Last call
(call to the latest call number) ○Ｘ
Hot call (Prompt call) ○○
Present time notice ○○
Find mobile phone ○○
Caller ID TTS ○○
Voice Memo ○Ｘ
Factory reset ○○
Available for siri and voice talk
modes ○○

- 13 -
What does LED color mean?
Status LED indication
Standby Purple LED blinks for every 5 seconds
Connection state Blue LED blinks for every 5 seconds
Battery is running low Blinks red light
Charging Red light ON
Fully charged Blue light ON
Pairing mode Blue light ON

- 14 -
FAQ & Troubleshooting
I hear crackling noises.
For the best audio quality, always locate your headset close to mobile phone.
I cannot hear anything.
- Increase the volume on the headset.
- Ensure that the headset is paired with the phone.
- Make sure that the phone is connected to the headset.
- If the headset fails to connect either when you pressed MFB or through
your mobile phone’s Bluetooth menu, Please refer to set up “Pairing mode” in Page 8.
I have problems with pairing even though my phone indicates otherwise.
Please delete the headset paired in your mobile and pair the headset again. Please refer to set up “Pairing
mode" in Page 6.
Will the MobiFren MFB-NB5100 work with other Bluetooth equipment?
MFB-NB5100 is designed to connect with Bluetooth mobile phone. You can also connect to a Bluetooth
device that supports the Bluetooth stereo headset handsfree profile.
Is the enclosed charging cable for only specified device?
It’s compatible with all standardized micro usb charger, and in general, compatible with Android mobile
phone charger.
When you use the headset in the car, the handsfree can be affected by the internal noise.

- 15 -
Handle MobiFren with care
Always store the MobiFren MFB-NB5100 with the power off and protect safely when
it’ s not in use.
Avoid storage at extreme temperature.
(above 60 ℃ / 140 ℉ -including direct sunlight -or below -20 ℃ / - 4 ℉ )
This can affect the MobiFren’s battery life and may be the cause of malfunction.
High temperature may also degrade performance.
Do not expose the MobiFren MFB-NB7100 to rain or other liquids
Prevent baby, children or pets to bite or suck this headset.
Please do not disassemble at user’s option.
Please make sure to use certified charger. (Rated Voltage : 5V)

- 16 -
Certification and safety approvals
FCC ID : UZCMFB-NB5100S
These limits are designed to provide reasonable protection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance
with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception, which can be determined by turning
the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following
measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and receiver.
- Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help.
CAUTION : Changes or modifications not expressly approved by the manufacturer responsible for compliance
could void the user’s authority to operate the equipment.
Made in Korea
In accordance with the R & TTE Directive 1999 / 5 / EC of 09. March 1999
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the
FCC Rules.
This device complies with RF exposure requirement.