Monster Shock Plus S21 Bluetooth Speaker User Manual

1. Introduction

Thank you for purchasing the Monster Shock Plus S21 Bluetooth Speaker. This manual provides essential information for setting up, operating, and maintaining your speaker. Please read it thoroughly before use to ensure optimal performance and longevity of your device.

Image: The Monster Shock Plus S21 speaker, highlighting its 30W audio performance for a powerful sound experience.

2. Package Contents

Verify that all items listed below are included in your package. If any items are missing or damaged, please contact customer support.

Image: The Monster Shock Plus S21 speaker and its accessories, including a lifting rope, AUX IN cable, USB-C charging cable, and quick start guide.

• Monster Shock Plus S21 Bluetooth Speaker x 1
• Lifting Rope x 1
• AUX IN Cable x 1
• USB-C Charging Cable x 1
• Quick Start Guide & Warning Card x 1

3. Product Overview

3.1. Buttons and Controls

Image: Top panel of the speaker displaying the power, volume down, play/pause, volume up, and mode (M) buttons.

• Power Button: Press and hold to turn on/off. Short press to check battery status (if applicable).
• Volume Down (-): Short press to decrease volume. Long press for previous track.
• Play/Pause Button (▶❚❚): Short press to play or pause music.
• Volume Up (+): Short press to increase volume. Long press for next track.
• Mode Button (M): Short press to switch between Bluetooth, AUX, and TF Card modes.

3.2. Ports and Connections

Image: Side panel of the speaker with the protective flap open, revealing the AUX-IN, TF Card slot, USB port, and Type-C charging port.

• AUX-IN Port: For connecting external audio devices via a 3.5mm audio cable.
• TF Card Slot: For playing music directly from a MicroSD/TF card.
• USB Port: For playing music directly from a USB flash drive.
• Type-C Charging Port: For charging the speaker using the provided USB-C cable.

4. Setup and First Use

4.1. Charging the Speaker

1. Connect the provided USB-C charging cable to the Type-C port on the speaker.
2. Connect the other end of the cable to a USB power adapter (not included) or a computer's USB port.
3. The charging indicator light will illuminate. It will turn off or change color once fully charged.
4. A full charge provides approximately 15 hours of playtime.

4.2. Powering On/Off

• To turn on: Press and hold the Power button until you hear an audible prompt.
• To turn off: Press and hold the Power button again until you hear an audible prompt.

5. Operating Instructions

5.1. Bluetooth Pairing

Image: The Monster Shock Plus S21 speaker, illustrating its advanced Bluetooth 5.4 connectivity for stable and fast pairing.

1. Ensure the speaker is powered on and in Bluetooth mode (indicated by a flashing blue LED). If not, press the 'M' button to switch modes.
2. Enable Bluetooth on your smartphone, tablet, or other Bluetooth-enabled device.
3. Search for "Monster Shock Plus S21" in the list of available devices.
4. Select "Monster Shock Plus S21" to connect. Once paired, you will hear a confirmation sound, and the LED indicator will turn solid blue.
5. The speaker will automatically reconnect to the last paired device when powered on, if the device's Bluetooth is active and within range.

5.2. AUX-IN Mode

• Connect one end of the 3.5mm AUX cable to the AUX-IN port on the speaker.
• Connect the other end to the audio output jack of your external device.
• The speaker will automatically switch to AUX mode, or you may need to press the 'M' button to select AUX mode.

5.3. TF Card / USB Playback

• Insert a TF card (MicroSD card) or a USB flash drive into the respective slot.
• The speaker will automatically detect the storage device and begin playing music.
• Press the 'M' button to cycle through playback modes if needed.

5.4. True Wireless Stereo (TWS) Pairing

Image: Two Monster Shock Plus S21 speakers positioned for TWS pairing, creating a stereo sound experience.

TWS allows you to pair two Monster Shock Plus S21 speakers together for a true stereo sound experience.

1. Ensure both speakers are powered off.
2. Turn on both speakers. They will enter Bluetooth pairing mode.
3. On one of the speakers (this will be your primary speaker), double-press the 'M' button. The speaker will search for the other speaker.
4. Once connected, you will hear a confirmation tone, and the LED indicators on both speakers will show a solid blue light.
5. Now, connect your Bluetooth device to the primary speaker as described in section 5.1.
6. Audio will play in stereo through both speakers.

Note: TWS pairing only works with two identical Monster Shock Plus S21 speakers.

6. Maintenance and Care

• Keep the speaker away from extreme temperatures, direct sunlight, and corrosive substances.
• Clean the speaker with a soft, damp cloth. Do not use harsh chemicals or abrasive cleaners.
• Ensure the port cover is securely closed when using the speaker near water to maintain its IPX6 waterproof rating.


Image: The Monster Shock Plus S21 speaker demonstrating its IPX6 water resistance, suitable for outdoor use.

• Store the speaker in a cool, dry place when not in use for extended periods.

7. Troubleshooting

8. Specifications

9. Warranty and Support

Monster products are designed and manufactured to the highest quality standards. For detailed warranty information and customer support, please refer to the warranty card included in your package or visit the official Monster website.

For assistance, please contact Monster customer support through their official channels. Keep your purchase receipt and product serial number handy for faster service.