1. Product Overview
The Monster Shock Plus Portable Bluetooth Speaker is designed to deliver powerful audio with versatile connectivity options. This manual provides essential information for safe and effective use of your device.

Front view of the Monster Shock Plus Portable Bluetooth Speaker, showcasing its black grille and top control panel.
2. Package Contents
Ensure all items are present in your package:
- 1x Monster Bluetooth Speaker
- 1x Lifting Rope
- 1x AUX IN Cable
- 1x USB-C Charging Cable
- 1x Quick Start Guide & Warning Card
3. Controls and Ports
Familiarize yourself with the speaker's controls and connection ports.
3.1 Top Panel Controls
- Power Button: Press and hold to power on/off. Short press to switch modes.
- Volume Down (-): Short press to decrease volume.
- Play/Pause Button: Short press to play or pause audio.
- Volume Up (+): Short press to increase volume.
- Mode/TWS Button (M): Short press to cycle through input modes (Bluetooth, AUX, TF Card, USB). Press and hold for TWS pairing.

The top panel features intuitive buttons for power, volume control, play/pause, and mode selection.
3.2 Rear Panel Ports
- AUX-IN Port: For connecting external audio devices via a 3.5mm audio cable.
- TF Card Slot: For playing audio directly from a MicroSD/TF card.
- USB Port: For playing audio directly from a USB drive.
- USB-C Charging Port: For charging the speaker.

The rear panel provides multiple input options including AUX, TF Card, USB, and USB-C for charging.
4. Setup
4.1 Charging the Speaker
- Connect the provided USB-C charging cable to the speaker's USB-C port.
- Connect the other end of the cable to a compatible USB power adapter (not included).
- The charging indicator light will illuminate. Once fully charged, the light will change or turn off.
A full charge provides up to 15 hours of playtime at 50% volume.

The speaker offers up to 15 hours of continuous music playback on a single charge.
4.2 Powering On/Off
- To Power On: Press and hold the Power button for approximately 2-3 seconds until you hear an audible prompt and the indicator light illuminates.
- To Power Off: Press and hold the Power button for approximately 2-3 seconds until you hear an audible prompt and the indicator light turns off.
4.3 Bluetooth Pairing
The speaker features Bluetooth 6.0 for stable and fast connections.
- Ensure the speaker is powered on and in Bluetooth mode (indicated by a flashing blue light and an audible 'Discovering' prompt). If not, short press the 'M' button to switch to Bluetooth mode.
- On your mobile device, enable Bluetooth and search for available devices.
- Select 'Monster Shock Plus' from the list of devices.
- Once connected, you will hear an audible 'Device is connected' prompt, and the blue indicator light will become solid.

Advanced Bluetooth 6.0 technology ensures a stable and efficient wireless connection.
4.4 True Wireless Stereo (TWS) Pairing
Pair two Monster Shock Plus speakers for a combined 60W stereo sound experience.
- Ensure both speakers are powered on and in Bluetooth mode, but not connected to any device.
- On one speaker (this will be the primary speaker), press and hold the 'M' button until you hear a pairing tone.
- The two speakers will automatically connect to each other. Once connected, you will hear a confirmation tone.
- Now, connect your mobile device to the primary speaker via Bluetooth as described in Section 4.3.

TWS pairing allows two speakers to create a wider, more immersive stereo soundstage.
5. Operating Instructions
5.1 Playing Audio
- Bluetooth Mode: After successful pairing, play audio from your connected device. Use the Play/Pause button on the speaker or your device to control playback.
- AUX Mode: Connect an audio device using the 3.5mm AUX cable. The speaker will automatically switch to AUX mode or can be selected using the 'M' button.
- TF Card/USB Mode: Insert a TF card or USB drive with audio files. The speaker will automatically switch to the respective mode or can be selected using the 'M' button.
5.2 Volume Control
- Increase Volume: Short press the '+' button.
- Decrease Volume: Short press the '-' button.
5.3 Hands-Free Calling
When connected via Bluetooth, the built-in microphone allows for hands-free calls.
- Answer Call: Short press the Play/Pause button.
- End Call: Short press the Play/Pause button.
- Reject Call: Press and hold the Play/Pause button.
5.4 Official Product Video
Watch this video for a visual guide on the speaker's features and operation.
Official brand video demonstrating the Monster Shock Plus speaker's key features and functionalities.
6. Maintenance
6.1 Water Resistance (IPX6)
The Monster Shock Plus speaker is IPX6 water-resistant, meaning it is protected against powerful water jets. It is suitable for outdoor use and can withstand splashes, but it should not be submerged in water.

The IPX6 rating ensures the speaker is protected from water splashes and jets, making it ideal for outdoor environments.
6.2 Cleaning
To clean the speaker, use a soft, damp cloth. Do not use abrasive cleaners or solvents, as these may damage the surface.
6.3 Battery Care
To prolong battery life, fully charge the speaker before first use. If the speaker will not be used for an extended period, charge it at least once every three months.
7. Troubleshooting
If you encounter issues with your speaker, refer to the following common solutions:
- Speaker does not power on: Ensure the battery is charged. Connect the speaker to a power source using the USB-C cable.
- Cannot pair via Bluetooth: Make sure the speaker is in Bluetooth pairing mode (flashing blue light). Ensure your device's Bluetooth is enabled and within range. Try restarting both the speaker and your device.
- No sound: Check the volume levels on both the speaker and your connected device. Ensure the correct input mode is selected (Bluetooth, AUX, TF Card, USB).
- Poor sound quality: Move the speaker closer to your Bluetooth device to reduce interference. Ensure the audio source is of good quality.
- TWS pairing issues: Ensure both speakers are not connected to any other Bluetooth device before initiating TWS pairing. Follow the TWS pairing steps carefully.
8. Specifications
| Feature | Specification |
|---|---|
| Model Name | Monster Shock Plus |
| Item Model Number | Monster S21 |
| Speaker Maximum Output Power | 30 Watts |
| Bluetooth Version | 6.0 |
| Playtime | Up to 15 Hours |
| Water Resistance Level | IPX6 (Water Resistant) |
| Connectivity Technology | Auxiliary, Bluetooth, USB, TF Card |
| Wireless Communication Technology | Bluetooth |
| Product Dimensions | 2.99"D x 10.08"W x 4.02"H |
| Item Weight | 1.54 pounds (0.7 Kilograms) |
| Material | Plastic |
| Power Source | Battery Powered (1 12V battery included) |
9. Warranty and Support
9.1 Warranty Information
The Monster Shock Plus Portable Bluetooth Speaker comes with a Limited Warranty. Please refer to the included Quick Start Guide & Warning Card for specific warranty terms and conditions.
9.2 Customer Support
For further assistance or technical support, please visit the official Monster website or contact their customer service department. Contact information can typically be found on the product packaging or the brand's official website.





