1. Introduction
This manual provides comprehensive instructions for the setup, operation, and maintenance of your FIFINE K031B Wireless USB Microphone System. This system offers a versatile audio solution for various applications, including online meetings, teaching, video recording, and live speeches, providing freedom of movement with its wireless design.
The K031B system includes both a headset microphone and a lavalier (lapel) microphone, allowing you to choose the best option for your specific needs. It operates on UHF frequencies for clear, static-free transmission and is designed for plug-and-play compatibility with PC and Mac computers, as well as iPads and iPhones (with appropriate adapters, not included).
2. Package Contents
Please verify that all items listed below are included in your package:
- UHF Wireless Transmitter (Bodypack)
- USB Receiver
- Headset Microphone
- Clip-on Lavalier Microphone
- User Manual (this document)

3. Component Overview


- UHF Wireless Transmitter (Bodypack): This unit connects to either the headset or lavalier microphone. It features an ON/OFF button, an LCD information display for system operation, and a battery compartment for two AA batteries.
- USB Receiver: This compact device plugs into your computer's USB port. It receives the wireless audio signal from the transmitter and acts as the interface for your computer. It is powered by the USB port.
- Headset Microphone: A lightweight microphone designed to be worn on the head, providing hands-free operation. It connects to the bodypack transmitter.

Image: Detailed view of the headset microphone, illustrating the flexible boom and the ear cushion (note: this is not an earphone for audio output). - Clip-on Lavalier Microphone: A small, discreet microphone designed to clip onto clothing, such as a lapel or tie. It also connects to the bodypack transmitter.
4. Setup Instructions
- Install Batteries in Transmitter: Open the battery compartment on the UHF Wireless Transmitter. Insert two AA batteries, ensuring correct polarity. 1.5V alkaline batteries are recommended for optimal performance.

Image: The USB receiver connected to a laptop, and the bodypack transmitter with its battery cover open, showing where to insert AA batteries. - Connect Microphone to Transmitter: Plug either the headset microphone or the lavalier microphone into the input port on the top of the UHF Wireless Transmitter.
- Power On Transmitter: Press and hold the ON/OFF button on the transmitter until the LCD screen illuminates.
- Connect USB Receiver to Computer: Plug the USB Receiver into an available USB port on your PC or Mac. The receiver will automatically install necessary drivers. A blue light on the receiver indicates a successful connection.

Image: A laptop screen displaying sound settings. It shows the USB PnP Audio Device selected as the microphone input and the USB Audio Device as the speaker output, with a blue light on the USB receiver indicating connection. - Select Microphone Input:
- For Windows: Go to Sound Settings > Recording tab. Select "USB PnP Audio Device" as your default microphone.
- For Mac: Go to System Preferences > Sound > Input tab. Select "USB PnP Audio Device" as your input device.
- Compatibility Note for Mobile Devices: For use with iPads and iPhones, a Lightning USB Camera Adapter (not included) is required. The system is equipped with a USB-C interface; adapters for other devices are not included.

Image: The USB receiver connected to an iPhone using a Lightning USB Camera Adapter, demonstrating mobile device compatibility (adapter not included).
The receiver automatically pairs with the transmitter, making setup plug-and-play. The LCD display on the transmitter provides continuous monitoring of system operation, including battery status with a low battery warning.
5. Operating Instructions
5.1. Using the Headset Microphone
The headset microphone is ideal for presentations, teaching, or any situation requiring hands-free communication. Position the microphone element approximately 1-2 inches from your mouth for optimal sound capture.

5.2. Using the Lavalier Microphone
The lavalier microphone is suitable for interviews, video recording, or situations where a discreet microphone is preferred. Clip it onto your clothing, such as a lapel or collar, ensuring it is positioned to capture your voice clearly.
5.3. Wireless Operation
The system operates on UHF frequencies, providing a clear and stable wireless connection. The operating range is approximately 80 feet, though this can vary depending on environmental factors such as obstructions (metal objects, human bodies) and signal strength. The system features preset 20 optional frequencies and automatic pairing to minimize interference from Bluetooth or Wi-Fi devices.

Important Note: The wireless headset does not have a monitoring function. This system is not designed to work with speaker systems or mixers, even if they have a USB input, as it is primarily intended for direct connection to computers and compatible mobile devices.
6. Maintenance
- Cleaning: Use a soft, dry cloth to clean the surfaces of the transmitter, receiver, and microphones. Avoid using liquid cleaners or solvents.
- Battery Replacement: Replace AA batteries in the transmitter when the low battery warning appears on the LCD display. Always use fresh 1.5V alkaline batteries.
- Storage: When not in use, store the microphone system in a cool, dry place away from direct sunlight and extreme temperatures.
- Cable Care: Avoid sharp bends or kinks in the microphone cables to prevent damage.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound or low volume. |
|
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| Interference or static. |
|
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| Microphone not recognized by computer. |
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If you encounter issues not covered here, please refer to the support section for further assistance.
8. Specifications
- Model: K031B
- Frequency Range: 565.0-584.0MHz
- Connectivity Technology: USB
- Microphone Form Factor: Handheld (refers to the bodypack transmitter, which holds the mic input)
- Polar Pattern: Unidirectional
- Audio Sensitivity: 58 dB
- Signal-to-Noise Ratio: 58 dB
- Frequency Response: 15 KHz
- Number of Channels: 1 (audio channel)
- Power Source (Transmitter): 2 AA batteries (1.5V alkaline recommended)
- Power Source (Receiver): USB 5V (from computer)
- Material: Metal (for some components, though plastic is also present)
- Item Weight: 12.3 ounces
- Package Dimensions: 7.87 x 6.38 x 2.72 inches
- FCC ID: 2ANTE-FIFINEMIC05
- UPC: 728290253660, 728290254131
9. Warranty and Support
9.1. Warranty Information
Specific warranty details for the FIFINE K031B Wireless USB Microphone System may vary by region and retailer. Please retain your proof of purchase for any warranty claims. For detailed warranty terms, refer to the documentation provided at the time of purchase or visit the official FIFINE website.
9.2. Customer Support
For technical assistance, troubleshooting, or product inquiries, please contact FIFINE customer support through their official website or the contact information provided with your product packaging. You can also visit the FIFINE Store on Amazon for additional resources.





