LEXIN LX-B4FM Motorcycle Bluetooth Intercom

Table of Contents

• Function Introduction
• Product Packaging
• Installation Instructions
• Basic Operation
• Bluetooth Connectivity
• Group Call Function
• Troubleshooting
• Maintenance & Certification
• Warranty
• Returns & Exchanges

Function Introduction

The LX-B4FM is a universal intercom system for motorcycles, featuring:

• Bluetooth 5.0
• CVC & DSP Noise Cancellation
• USB Type-C Connector
• Voice Guidance
• Hands-free Calling
• Music Playback
• Navigation Audio Prompts
• FM Radio
• Voice Control (Siri/Google Assistant)
• Connectivity with other intercom brands
• Music Sharing

The LX-B4FM supports up to 10 units with a visible range of approximately 2000 meters for intercom calls. It is compatible with HSP, HFP, A2DP Bluetooth profiles, allowing pairing with other Bluetooth-enabled intercoms.

Speaker

Equipped with 36mm high-quality stereo speakers. The detachable speaker microphone is suitable for both jet and full-face helmets. The speakers deliver clear audio, and the noise-canceling microphone reduces wind noise for a powerful sound experience even while riding.

Battery

Features an 800mAh lithium battery providing approximately 15 hours of continuous talk time or music playback, and up to one week of standby time. Actual usage time may vary based on usage environment.

Function Priority

When multiple functions are active simultaneously, they operate based on the following priority (higher priority functions interrupt lower priority ones):

1. Smartphone/Mobile Phone Calls
2. Intercom Calls
3. Music / FM Radio / Navigation Audio

Note: For example, if listening to FM radio and an intercom call comes in, the radio will pause. If on an intercom call and a smartphone call arrives, the intercom call will be interrupted.

Safety Precautions

Caution: Please check the laws and regulations of your region regarding the use of mobile phones or communication devices while operating a motorcycle.

Product Packaging

The LX-B4FM package includes the following items:

• LX-B4FM Main Unit
• 36mm HD High-Quality Stereo Speakers
• Mounting Bracket Base
• Mounting Bracket
• 3M Double-Sided Tape Bracket
• Boom/Wire Microphone
• Arm Microphone Holder
• Instruction Manual
• USB Type-C Charging Cable
• Bracket Plastic Pad
• 2x Bracket Rubber Pads
• 2x Speaker Pads
• Removal Pad
• 1x Screwdriver and 4x Screws

Diagram Description: The package contents are visually laid out, showing the main LX-B4FM unit, speakers, microphones (boom and wire), various mounting brackets and accessories, cables, and different types of pads.

Installation Instructions

Mounting the Bracket

There are two methods for mounting the bracket:

1. Screw-Type Mounting

Insert the mounting bracket between the helmet shell and the inner lining. Secure the bracket base to the mounting bracket using screws. Adjust the bracket thickness by adding rubber pads (A or B) as needed based on helmet thickness. If using the plastic pad, use the two longer screws; otherwise, use the two shorter screws.

Diagram Description: Illustrates attaching the bracket to a helmet using screws. Shows placement options for rubber pads (A, B) to adjust bracket thickness and the use of longer or shorter screws depending on whether the plastic pad is used.

2. 3M Double-Sided Tape Mounting

Use the 3M double-sided tape bracket if the screw-type mounting is not preferred or usable. Ensure the helmet surface is clean and free of oil before applying the tape. Press firmly and allow approximately 24 hours before use. Note: Screw-type mounting is recommended. The manufacturer is not liable for any damages resulting from tape mounting.

Diagram Description: Shows a helmet with the 3M adhesive bracket being applied to the side.

Mounting and Removing the Intercom Unit

Align the LX-B4FM unit with the bracket and slide it down until it clicks securely into place. To remove the unit, insert the provided removal pad between the unit and the bracket, then push the unit upwards from the bottom.

Diagram Description: Shows the LX-B4FM unit being slid onto the bracket until it locks, and then being detached using a removal pad.

Speaker Installation

Note: For optimal FM radio reception, install the speaker with the shorter wire on the left side and the speaker with the longer wire on the right side.

1. Position the speakers inside the helmet and secure them using the included Velcro pads.
2. If the helmet's ear pockets are deep, use the included speaker pads for adjustment.
3. Route the speaker wires neatly inside the helmet lining.

Diagram Description: Illustrates placing speakers inside a helmet and securing them with Velcro. Also shows the use of speaker pads for adjustment in deep ear pockets.

Microphone Installation

Note: Use the wire microphone for full-face helmets and the boom microphone for open-face helmets. Both are compatible with either helmet type.

Wire Microphone Installation

1. For full-face helmets, attach the wire microphone to the center area of the helmet using the Velcro pad.
2. Secure the wire microphone to the Velcro pad.
3. Connect it to the left speaker.

Diagram Description: Shows the wire microphone being attached to the inside of a full-face helmet using Velcro.

Boom Microphone Installation

1. Attach the Velcro pad to the helmet's inner lining using double-sided tape.
2. Attach the boom microphone to the Velcro pad. Ensure the white triangle mark on the microphone faces towards your mouth.
3. Use the arm microphone holder if necessary.

Diagram Description: Shows the boom microphone being attached to the inside of a helmet using Velcro, with an illustration of correct positioning towards the mouth. Also shows the optional microphone holder.

Note: If your helmet's ear pockets are deep, use the included speaker pads for adjustment.

Basic Operation

Diagram Description: A diagram of the LX-B4FM unit showing the location of all buttons and ports: Intercom Button, Power Button, Volume + Button, Volume - Button, LED Indicator, USB Type-C Earphone Port, and USB Type-C Charging Port.

Powering On/Off

To Power On: Simultaneously press and hold the Power button and the Intercom button for approximately 1 second. The blue LED will flash, indicating the unit is on.

To Power Off: Simultaneously press and hold the Power button and the Intercom button for approximately 1 second. The red LED will flash once, indicating the unit is off.

Battery

Charging

Connect the LX-B4FM unit to a charger using the USB Type-C cable. Charging can be done using a DC 5V power source, such as a smartphone charger or a computer's USB port. The charger itself is not included.

• The red LED will blink during charging.
• The blue LED will light up when charging is complete.
• Full charging takes approximately 3 hours.

Low Battery Alerts

• When the battery level drops below 30%, the unit will beep every 5 minutes to indicate low battery.
• A "Battery Low" announcement will be made approximately 1 to 1.5 hours before the battery runs out.

Battery Level Check

Upon powering on the LX-B4FM, the unit will announce the current battery level. You can also check the battery level by pressing and holding the Volume - button for approximately 1 second. The unit will announce the battery level (e.g., 100% → 80% → 50% → 30% → Battery Low).

Volume Adjustment

Use the Volume + and Volume - buttons to adjust the volume. A single press adjusts the volume by one step, while pressing and holding the button adjusts it continuously.

• Press Volume + to increase volume.
• Press Volume - to decrease volume.

Note: For the best music listening experience, ensure your smartphone's volume is set to maximum.

A beep sound will be heard when the volume reaches its maximum or minimum level.

Note: Volume can be adjusted during music playback, FM radio, intercom calls, or when receiving calls.

Playback Control

• Press the Power button once to play music. Press it again to pause playback.

Track Change

• While music is playing, double-press the Volume + button to skip to the next track.
• While music is playing, double-press the Volume - button to go back to the previous track.

Music Sharing

Share music playback between two LX-B4FM units (Unit A and Unit B).

1. While Unit A is playing music, press the Power button twice to enter sharing mode.
2. When Unit B is in standby mode, press its Power button twice. Unit B will connect to Unit A, and music will play through Unit B's speakers.

Note: Music sharing is only possible between two LX-B4FM units. It cannot be shared with three or more units.

To end music sharing: Press the Power button twice on either Unit A or Unit B.

Bluetooth Connectivity

Note: One LX-B4FM unit can connect to a maximum of two other LX-B4FM units and one smartphone simultaneously.

After pairing, the LX-B4FM will automatically reconnect to connected devices when powered on, provided their Bluetooth is enabled. You can also initiate an automatic reconnection by pressing the Power button once while in standby mode.

Smartphone Pairing

1. With the unit powered off, press and hold the Power button for approximately 5 seconds until the LED lamp flashes blue and red. This indicates pairing mode.
2. Note: For GPS pairing, press and hold the Intercom button.
3. On your smartphone, search for Bluetooth devices and select "LX-B4FM".
4. Tap to begin pairing. If prompted for a PIN, enter "0000".
5. Confirm that the pairing was successful on your smartphone.

Note: The LX-B4FM's LED lamp will flash blue rapidly when pairing is complete.

Universal Intercom Pairing

You can pair the LX-B4FM with intercom units from other brands.

1. While in standby mode, press and hold the LX-B4FM's Intercom button for approximately 1 second until the LED lamp flashes blue and red to enter pairing mode.
2. Follow the instructions in the other intercom unit's manual to put it into pairing mode.
3. Press the Intercom button once on the LX-B4FM. The blue LED will flash rapidly. When the blue LED flashes slowly, pairing is complete.
4. After successful pairing, press the Volume + and Volume - buttons simultaneously once to initiate a call.
5. Press the Power button once during a call to end it.

Group Call Function

The LX-B4FM utilizes full-duplex Bluetooth communication to enable group calls. It supports group calls for up to 4 people or for 5 or more people.

Important Notes:

• It is recommended to reset the units before pairing for group calls. To reset, press and hold the Volume + and Volume - buttons simultaneously for approximately 1 second. The red LED will flash, indicating the reset is complete.
• The default setting for the LX-B4FM is 4-person group calls. To switch to the 5+ person group call mode, press and hold the Power button for approximately 8 seconds while in standby mode. You will hear "bib bib" sounds, and the red indicator line will flash three times rapidly.
• This mode setting is not saved. If you power cycle the LX-B4FM, it will revert to 4-person mode. You must re-enable the 5+ person mode each time you wish to use it.

Pairing for 2 Units

Step 1: Connect two LX-B4FM units.

1. Power on both LX-B4FM units. Press and hold the Intercom button on both units for approximately 1 second. The LED lamps will flash blue and red, indicating pairing mode.
2. Press the Intercom button once on either LX-B4FM unit. The unit will automatically search for and connect to the other device. The blue LED will flash rapidly during connection and flash slowly when pairing is complete. An audio prompt will confirm pairing.

Diagram Description: Shows two LX-B4FM units. Arrows indicate pressing the Intercom button on both. Then, one unit's Intercom button is pressed, leading to a connection state with flashing LEDs, and finally a paired state with slow flashing LEDs.

2-Unit Call: After pairing, press the Intercom button once on either unit to initiate a call. Press the Power button once to end the call. To resume the call, press the Intercom button once.

Note: For pairing two LX-B4FM units, only Step 1 is required.

Pairing for 3 Units

Step 1: Pair the first and second LX-B4FM units as described above.

Step 2: Connect the third LX-B4FM unit.

1. Power on the third LX-B4FM unit. Press and hold the Intercom button and the Volume - button simultaneously on both the second and third units for approximately 1 second. The LED lamps will flash blue and red, indicating pairing mode.
2. Press the Intercom button once on either the second or third unit. The unit will automatically search for and connect to the other device. The blue LED will flash rapidly during connection and flash slowly when pairing is complete.

Diagram Description: Shows three LX-B4FM units. Step 1 shows pairing of unit 1 and 2. Step 2 shows units 2 and 3 being paired by pressing Intercom and Volume - buttons, followed by a single Intercom button press to connect.

3-Unit Call: After pairing, press the Intercom button once on any of the three units to start a group call. Press the Power button once to exit the group call; the person who pressed the button will leave, potentially splitting the group into two. Pressing the Intercom button again will allow the person to rejoin the group call.

Note: For pairing three LX-B4FM units, follow up to Step 2.

Pairing for 4 Units

To connect up to four LX-B4FM units, follow these steps:

1. Pair the first and second units according to Step 1.
2. Pair the second and third units according to Step 2.
3. Pair the third and fourth units according to Step 1. Press and hold the Intercom button on both the third and fourth units for approximately 1 second. The LED lamps will flash blue and red, indicating pairing mode.
4. Press the Intercom button once on either the third or fourth unit. The unit will automatically search for and connect to the other device. The blue LED will flash rapidly during connection and flash slowly when pairing is complete.

Diagram Description: Illustrates the sequential pairing process for four LX-B4FM units, showing the button presses and LED indicators for each stage of connecting units 1-2, 2-3, and 3-4.

4-Unit Call: After pairing, press the Intercom button once on any of the four units to start a group call. Press the Power button once to exit the group call. Pressing the Intercom button again will allow the person to rejoin the group call.

Note: You can connect up to four LX-B4FM units in this manner.

Pairing for 5 or More Units

The default setting for the LX-B4FM is 4-person group calls. To enable calls for 5 or more people, you must switch to the 5+ person mode.

1. Switching to 5+ Person Mode: While in standby mode, press and hold the Power button on all intercom units for approximately 8 seconds. You will hear "bib bib" sounds, and the red indicator line will flash three times rapidly. This confirms the switch to 5+ person mode. Note: This setting is not persistent and will revert to 4-person mode upon power cycling. You must re-enable 5+ person mode each time.
2. Pairing Process:
3. Pair the first and second units.
4. Pair the second and third units.
5. Pair the third and fourth units.
6. Pair the fourth and fifth units. Press and hold the Intercom button and the Volume - button simultaneously on both the fourth and fifth units for approximately 1 second until the LED lamps flash blue and red.
7. Press the Intercom button once on either the fourth or fifth unit. The unit will automatically search for and connect to the other device. A slow blue LED flash indicates pairing is complete.

Diagram Description: Shows a summary of the group call pairing sequence for up to 5 units, illustrating the chain connection and button presses required.

Note: One LX-B4FM unit can connect to a maximum of two other LX-B4FM units simultaneously (e.g., one unit connected to two others). If unit 3 is paired with unit 2 and unit 4, it cannot connect to other devices.

5+ Unit Call: After pairing, press the Intercom button once on any unit to start a group call. If one person presses the Power button, they will leave the call, potentially splitting the group into two. Pressing the Intercom button again allows them to rejoin the group call.

Troubleshooting

If you encounter issues, please refer to this guide. If problems persist, contact customer support.

LX-B4FM Unit Not Powering On

• Check if the unit is powered on.
• Ensure the battery is sufficiently charged.
• Verify the red LED is lit during charging.
• Try using a different USB cable, power adapter, and power outlet to confirm charging capability.
• Charge for 3 hours and check if the LED turns blue.

LX-B4FM Not Syncing with Smartphone/Mobile Phone

• Ensure the unit is powered on.
• Ensure the battery is sufficiently charged.
• Confirm that your smartphone/mobile phone is capable of making calls.
• Ensure Bluetooth is enabled on your smartphone/mobile phone.
• Verify that pairing between the unit and your smartphone/mobile phone was completed successfully.
• Reset the LX-B4FM unit. Restart your smartphone/mobile phone, then re-pair them following the instructions in this manual. You may need to remove the LX-B4FM from your phone's Bluetooth device list, turn off Bluetooth, and then turn it back on.

Microphone Not Working (Your Voice Not Heard by Others)

• Ensure the speaker microphone is securely plugged into the unit.
• Confirm that the microphone part is properly attached to the helmet.
• Make sure the microphone's sound intake hole is facing your mouth.
• Try swapping with the other microphone included in the package to see if it resolves the issue.

Maintenance & Certification

Firmware updates may be available to improve performance or resolve issues. For upgrade information, please contact katelin@lexinmotorcycle.com. Updates are generally not necessary if the product is functioning correctly.

Certifications

• FCC Regulations: This product complies with FCC (Federal Communications Commission) rules and has obtained CE marking.
• GITEKI Mark (技適マーク): This product has obtained the GITEKI mark, indicating compliance with Japanese radio regulations.

Important Safety Precautions

Please read the following precautions carefully to ensure safe use of the LX-B4FM:

• Always comply with local traffic laws and regulations of your prefecture and municipality when using this product on roads.
• Do not listen to audio at excessively high volumes while riding. This can prevent you from hearing important traffic sounds, potentially leading to serious accidents.
• Do not apply excessive force to the unit, as this may cause damage, malfunction, or other operational failures.
• Do not disassemble or modify the product. Doing so may cause fire or electric shock.

Warranty

Warranty Period

• Product Name: LX-B4FM
• Warranty Period: 1 year for the intercom unit, 6 months for the speaker microphone from the date of purchase.

Warranty Terms

This product is covered by a one-year warranty from the date of purchase. LEXIN will provide free repair or replacement for manufacturing defects or material failures within this period. However, the warranty does not cover damage caused by misuse, accidents, unauthorized repairs or modifications, or natural disasters. The speaker microphone is considered a consumable item and has a 6-month warranty. LEXIN is not liable for any direct or indirect damages, including accidents, injuries, loss of time, inconvenience, loss of profit, or incidental expenses. Cosmetic damage or external abrasions on the unit are not covered. Please contact LEXIN for warranty service requests. Paid repairs may be necessary even within the warranty period for certain issues. Damage caused by water ingress is not covered under any circumstances.

Returns & Exchanges

If you experience an initial defect or an issue within the warranty period, please contact your point of purchase.

For purchases made on Amazon.co.jp, please contact:

When contacting us regarding an initial defect or a warranty claim, please provide the following information:

• Product Name
• Serial Number
• Place of Purchase, Date of Purchase, and Proof of Purchase (Warranty Card)
• Description of the Fault
• Your Name
• Your Address
• Your Contact Information