LEXIN LX-B4FM Motorcycle Bluetooth Intercom

Introduction to Features

The LEXIN LX-B4FM is a motorcycle Bluetooth intercom system with the following features:

• Bluetooth 5.0
• CVC and DSP noise reduction
• USB-C fast charging
• Voice prompt for power on/off and voice dialing
• Voice assistant compatibility (e.g., Siri)
• Hands-free phone calls
• Music playback
• GPS navigation connection
• FM Radio playback
• Music sharing
• Universal pairing with most Bluetooth devices
• Supports connection of up to 10 LX-B4FM units
• Maximum range of 2000M (1.2 miles)
• Compliant with Bluetooth V5.0 specifications (HSP, HFP, A2DP)

Battery

The LX-B4FM features an 800mAh battery providing up to 15 hours of music playback or 15 hours of talk time, with 1 week of standby time.

Function Priority

The LX-B4FM prioritizes functions in the following order:

1. Mobile phone
2. Intercom
3. Music/Radio/GPS

Note: Lower priority functions are interrupted by higher priority ones (e.g., intercom interrupts music, phone calls interrupt intercom).

Safety Information

Warning: When operating a vehicle, ensure compliance with all local laws and regulations regarding helmet speaker usage.

Package Contents

The package includes:

• Main Unit LX-B4FM
• 36mm ultra-thin high-definition speaker
• Mounting base
• Metal back clip
• Rear clip plastic pad
• 2x Rear clip rubber pads
• Tool for main unit removal
• 3M adhesive for mounting base
• Boom microphone or button microphone
• Microphone fixing piece
• User manual/Simple instructions
• USB-C data cable
• Speaker pads
• 4x Male key and mounting screws

Diagram Description: The page displays a diagram illustrating the main unit, speakers, microphones, and various mounting accessories, along with their labels.

Mounting Instructions

Helmet Mounting

1. Screw Mount: Attach the metal back clip between the helmet liner and the helmet shell. Secure the clip and base with hex screws. Adjust with included rubber pads (0-2pcs) for optimal fit based on helmet thickness. Use longer screws for plastic mounting pads if needed.
2. 3M Adhesive Mount: Alternatively, remove the protective film from the 3M adhesive on the mounting base and attach it to the helmet. Press firmly for 15 seconds and allow 24 hours for the adhesive to cure.

Attaching the Main Unit: Slide the main LX-B4FM unit downwards onto the mounting base until it clicks securely into place.

Removing the Main Unit: Use the provided tool to detach the main unit from the base.

Speaker Installation

Note: The speaker with the shorter wire is for the left ear, and the longer wire is for the right ear to improve FM radio reception. The speaker attaches to the helmet liner. If the helmet has a deeper ear pocket, use the included ear pads to position the speaker closer to your ear.

1. Attach the VELCRO half to the inside of the helmet.
2. Press the speaker firmly onto the VELCRO. Use the included pad to elevate the speaker if the helmet has a deeper ear pocket.
3. Tuck any excess speaker wire between the interior and the helmet shell.

Note: For helmets with deep ear pockets, use the included speaker pads to increase speaker thickness.

Microphone Installation

Note: Both boom and button microphones can be used interchangeably for full-face or open-face helmets. Choose based on preference and helmet type.

Open-face helmet / Boom microphone

1. Find a suitable area on the helmet for mounting the microphone. Attach the VELCRO half to the microphone.
2. Attach the microphone to the VELCRO on the helmet.
3. Connect the microphone to the earphone connector on the left side.

Open-face helmet / Button microphone

1. Attach one half of the VELCRO to the base of the microphone and the other half to the inside of the helmet.
2. Adjust the microphone direction so the triangle mark points towards your mouth.
3. If necessary, use the microphone support for additional positioning.

Basic Operation

Powering On/Off

To turn on/off: Press and hold the Power button and the Intercom button simultaneously for 1 second. The LED will flash blue, and a voice prompt will indicate power status and battery percentage.

Battery

Charging the Battery

Connect the USB-C cable to the LX-B4FM's USB-C port and charge from any DC 5V power source (phone charger, computer, power bank). The LED is red while charging and turns blue when fully charged. Charging takes approximately 3 hours.

Low Battery Warning

When the battery is below 30%, a voice prompt will sound every 5 minutes, indicating approximately 1-1.5 hours of remaining use. Below 20%, the device will shut down.

Battery Level Alerts

The intercom announces the current battery level upon startup. You can also double-press the Volume Down button to check the battery level. Levels are indicated as 100%, 80%, 50%, 30%, or low battery.

Bluetooth Pairing

Pairing with a Phone

1. With the device powered off, press and hold the Power button for about 5 seconds until the LED flashes blue and red.
2. Note: Do not use the Intercom button for phone/GPS pairing.
3. On your phone's Bluetooth settings, select "LX-B4FM".
4. Connect and enter PIN 0000 if prompted.
5. Confirm pairing on your phone. A solid blue LED indicates a successful connection.

Pairing with GPS Navigation

1. With the device powered off, press and hold the Power button for about 5 seconds until the LED flashes blue and red.
2. Follow the GPS device's instructions for Bluetooth pairing.
3. Connect the LX-B4FM according to your GPS device's pairing instructions.
4. Note: After pairing, you will hear a voice prompt indicating the GPS connection.

Clearing Pairing History

Press and hold the Volume Up and Volume Down buttons simultaneously for about 1 second. The LED will flash blue and red, clearing the pairing history.

Volume and Music Control

Volume Adjustment

Press the Volume +/- buttons for a sound prompt when adjusting volume. The volume can only be adjusted during music/radio/conversation/call playback.

Press the volume button once to adjust volume incrementally. Press and hold to adjust continuously. Adjust phone volume simultaneously for higher overall volume.

Play/Pause Music

Click the Call button to pause music; click it again to resume playback.

Changing Tracks

Press Volume Up briefly for the next track; press Volume Down briefly for the previous track.

Music Sharing

An LX-B4FM unit playing music can share it with another LX-B4FM unit. The music-playing unit (A) double-clicks the power button to enter sharing mode. Unit B, in standby, also double-clicks the power button to search and connect to Unit A, then automatically plays the shared music. Music sharing is limited to two devices.

To stop music sharing: Double-click the power button on the LX-B4FM unit.

Phone Calls

• Answering a call: Press the Power button briefly when a call arrives.
• Auto-answer: The device will auto-answer after 12 seconds.
• Enable/Disable Auto-answer: Press and hold Volume + for 5 seconds. A triple blue flash indicates auto-answer is enabled; a triple red flash indicates it is disabled.
• Ending a call: Press the Power button briefly during a call.
• Rejecting a call: Press the Power button twice to reject a call.
• Redialing: In standby mode, double-press the Volume Up button to redial the last number.
• Phone Voice Assistant: In standby mode, double-press the Volume Down button to activate Siri or S-Voice.

Intercom Pairing

The LX-B4FM supports full-duplex intercom, including 4-way and group intercom modes, supporting up to 10 people.

Note: It is recommended to clear existing connections before pairing. To do this, press and hold Volume + and Volume - simultaneously until the LED flashes red rapidly.

The 4-way intercom mode is the default. To switch to group intercom for more than five people, press and hold the Power button for 8 seconds in standby mode. A beep and rapidly flashing red LED indicate the mode change. This setting is not remembered, so it must be re-selected when connecting more than 5 units.

Bluetooth Intercom Pairing

Pairing Two Units (2-way Intercom)

1. Press and hold the Intercom button on both LX-B4FM units for 1 second until the red and blue LEDs flash. A "pairing in progress" sound will occur.
2. Diagram Description: Shows two units with the Intercom button pressed, indicating pairing mode.
3. Press the Intercom button on either unit. The unit will search automatically, with a rapidly flashing blue LED during the search. After pairing, the blue LEDs on both units will flash slowly. A sound indicates successful pairing.
4. Starting Intercom Conversation: After successful pairing, click the Intercom button on one unit to start. The LED will flash blue and red simultaneously during conversation. Press the Power button to temporarily disconnect; click the Intercom button again to resume.
5. Note: For pairing only two LX-B4FM units, complete step ① and then start the intercom conversation.

Pairing Three Units (3-way Intercom)

1. After pairing two units (step ①), press the Intercom button and Volume - button on the second unit to pair with the third unit.
2. With the third unit in standby, press and hold the Intercom button and Volume - button on both the second and third units for 1 second until the red and blue LEDs flash. A "pairing in progress" sound will occur.
3. Diagram Description: Shows three units being paired, with specific button presses indicated.
4. Press the Intercom button on any unit to search. The blue LED flashes rapidly. After pairing, the blue LEDs on all three units flash slowly.
5. Starting Intercom Conversation: After successful pairing, click the Intercom button on one unit to start. The LED flashes blue and red. Press the Power button to temporarily disconnect; click the Intercom button again to resume.
6. Note: If only three devices need pairing, complete step ②. If the second unit disconnects, the others will also disconnect.

Pairing Four Units (4-way Intercom)

1. After steps ① and ② are complete, units 1, 2, and 3 are paired. Press the Intercom button to pair the third and fourth units.
2. In standby mode, press and hold the Intercom button on the third and fourth LX-B4FM units for 1 second to enter pairing mode. A "pairing in progress" sound will occur, and the red and blue LEDs will flash.
3. Diagram Description: Illustrates the pairing process for four units, showing button presses and LED indicators.
4. Press the Intercom button on any unit to search. The blue LED flashes rapidly. After pairing, the blue LEDs on all four units flash slowly.
5. Starting Intercom Conversation: After successful pairing, click the Intercom button on one unit to start. The LED flashes blue and red. Press the Power button to temporarily disconnect; click the Intercom button again to resume.
6. Note: If only four devices need pairing, complete step ③. If one unit disconnects, the group will split into two. Click the Intercom button again to reconnect.

Group Intercom (5+ Units)

The 4-way intercom is default. To switch to group intercom for more than five people, press and hold the Power button for 8 seconds in standby. A beep and rapidly flashing red LED indicate the mode change. This setting is not saved.

For pairing instructions for 4-way intercom, refer to the group intercom pairing section.

Diagram Description: Shows a unit with the Intercom button pressed for 8 seconds, indicating the transition to multi-intercom mode.

Group Association (5+ Units)

The group pairing rule repeats the steps for coupling multiple units.

Diagram Description: Illustrates a sequential pairing process for units 1 through 5, showing connections and button presses.

Note: Each LX-B4FM unit can be paired with a maximum of two other units, forming a chain. For example, after pairing unit 3 with units 2 and 4, if there are no free connections, it cannot be paired with another unit.

Starting Intercom Conversation: After successful pairing, click the Intercom button on one unit to start. The LED flashes blue and red. Press the Power button to temporarily disconnect; click the Intercom button again to resume.

Note: The group intercom will divide into two groups if a unit disconnects. Clicking the Intercom button again will reconnect the independent groups.

Connecting to Other Devices and Considerations

Bluetooth Group Talk Connection

• Devices connect in a chain. Maintain connection order for optimal communication.
• Group talk devices cannot be connected to a Bluetooth phone or GPS simultaneously.

Starting Intercom

It may take a few seconds for other devices to connect when starting a conversation. Wait for all devices to connect before initiating intercom.

Conversation Distance

If a rider is out of range during a conversation, noise or disconnection may occur. The B4FM will attempt to reconnect automatically every few seconds.

Saving Battery

Disconnect the walkie-talkie when not in use to save battery. Turn off the LED lamp if not needed.

Common Pairing

Pairing Other Bluetooth Intercoms

1. In on mode, press and hold the Intercom button for 1 second to enter pairing mode (alternating blue and red LED).
2. Enter pairing mode according to the other device's Bluetooth pairing instructions.
3. Press the LX-B4FM Intercom button to search. The LED flashes blue rapidly, then slowly upon connection.
4. After pairing, press the + and - buttons to enter intercom mode.
5. In conversation mode, press the Power button to end the conversation.

FM Radio

Saving FM Channels

In FM mode, press the Power button twice to save the current channel. A voice prompt will confirm. Up to 6 channels can be saved, with loop coverage.

Playing Saved FM Channels

In FM mode, briefly press the Power button to cycle through and play saved channels.

Radio On/Off

• Turn on FM Radio: Briefly press the Power button.
• Turn off FM Radio: While the radio is on, briefly press the Power button.

Radio Station Search

• Scan Down: Briefly press Volume Up. A voice prompt indicates scanning down.
• Scan Up: Briefly press Volume Down. A voice prompt indicates scanning up.