1. Introduction and Overview
The Monster Cubis Bluetooth Speaker is designed to provide powerful, clear audio in a compact and portable form factor. Featuring advanced Bluetooth 6.0, True Wireless Stereo (TWS) pairing, and IPX7 waterproofing, this speaker is suitable for various environments, from indoor relaxation to outdoor adventures. This manual provides detailed instructions for setting up, operating, and maintaining your speaker to ensure optimal performance and longevity.
2. What's in the Box
Carefully unpack your Monster Cubis Bluetooth Speaker and ensure all items are present:
- Monster Cubis Bluetooth Speaker ×1
- USB-C Charging Cable ×1
- AUX-in Cable ×1
- Quick Start Guide ×1
- Portable Lanyard ×1

3. Product Features
- Pure Monster Sound & 15W Powerful Audio: Experience room-filling, crystal-clear stereo sound with a robust 15W audio driver, delivering strong bass and minimal distortion.
- Advanced Bluetooth 6.0 & TWS Pairing: Enjoy faster pairing and a more stable connection with Bluetooth 6.0. Connect two Cubis speakers for an immersive True Wireless Stereo experience.
- 15H Playtime & Type-C Fast Charge: A built-in battery provides up to 15 hours of playback at 50% volume. The USB-C port allows for quick and convenient recharging.
- IPX7 Waterproof & Portable Design: With an IPX7 rating, the speaker is protected against immersion in water up to 1 meter for 30 minutes. Its compact size and built-in strap make it easy to carry.
- Multiple Connectivity Options: In addition to Bluetooth, the speaker supports 3.5mm AUX input and TF card playback for versatile audio sources.






4. Controls and Ports
Familiarize yourself with the speaker's buttons and connection ports:

- Power On/Off Button: Press and hold to power the speaker on or off.
- Play/Pause Button: Short press to play or pause music. Long press to disconnect Bluetooth. Double press to enter/exit TWS mode.
- Volume Down/Previous Song Button: Short press for volume down. Long press for previous song.
- Volume Up/Next Song Button: Short press for volume up. Long press for next song.
- Mode Switch Button (M): Press to switch between Bluetooth, AUX, and TF card modes.
- Type-C Charging Port: For charging the speaker.
- Charging Indicator: LED light indicating charging status.
- TF Card Port: Insert a TF card for local music playback.
- AUX-in Port: Connect external audio devices via a 3.5mm audio cable.
5. Setup
5.1. Charging the Speaker
Before first use, fully charge the speaker. Connect the provided USB-C charging cable to the speaker's Type-C port and the other end to a USB power adapter (not included) or a computer's USB port. The charging indicator will show the charging status and turn off when fully charged.
5.2. Powering On/Off
- To Power On: Press and hold the Power On/Off button until you hear an audible prompt.
- To Power Off: Press and hold the Power On/Off button until you hear an audible prompt.
5.3. Bluetooth Pairing
- Ensure the speaker is powered on and in Bluetooth mode (indicated by a flashing blue LED).
- On your device (smartphone, tablet, etc.), enable Bluetooth and search for available devices.
- Select "Monster Cubis" from the list of devices.
- Once connected, the LED indicator will turn solid blue, and you will hear a confirmation sound.
6. Operating Instructions
6.1. Music Playback
- Play/Pause: Short press the Play/Pause button.
- Volume Up: Short press the Volume Up (+) button.
- Volume Down: Short press the Volume Down (-) button.
- Next Track: Long press the Volume Up (+) button.
- Previous Track: Long press the Volume Down (-) button.
6.2. 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 during a call.
- Reject Call: Long press the Play/Pause button.
6.3. Switching Modes
Press the Mode Switch (M) button to cycle through available input modes: Bluetooth, AUX, and TF Card.
7. TWS (True Wireless Stereo) Pairing
To achieve a true stereo sound experience, you can pair two Monster Cubis speakers together.
- Ensure both Monster Cubis speakers are powered on and not connected to any Bluetooth device.
- On one speaker (this will be the primary speaker), double press the Play/Pause button. The speaker will enter TWS pairing mode, indicated by a specific LED pattern or audible prompt.
- The primary speaker will automatically search for and connect to the secondary speaker. Once connected, you will hear a confirmation sound, and the LED indicators on both speakers will change to reflect the TWS connection.
- Now, connect your device to the primary speaker via Bluetooth as described in section 5.3. Audio will play in stereo through both speakers.
- To exit TWS mode, double press the Play/Pause button on either speaker.

8. Maintenance
- Clean the speaker with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Avoid exposing the speaker to extreme temperatures or direct sunlight for prolonged periods.
- Ensure the charging port cover is securely closed when not charging, especially when near water, to maintain IPX7 waterproofing.
- Store the speaker in a cool, dry place when not in use.
9. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Speaker does not power on. | Battery is depleted. | Charge the speaker using the provided USB-C cable. |
| Cannot pair with Bluetooth device. | Speaker is not in pairing mode; device's Bluetooth is off; speaker is already connected to another device. | Ensure speaker is in pairing mode (flashing blue LED). Turn on Bluetooth on your device. Disconnect from other devices or restart the speaker. |
| No sound or low volume. | Volume too low on speaker or device; incorrect input mode; device not connected. | Increase volume on both speaker and device. Press 'M' button to select correct input mode. Re-pair Bluetooth if necessary. |
| Short battery life. | Playing at high volume; battery not fully charged; aging battery. | Battery life is significantly reduced at maximum volume. The stated 15 hours of playtime is typically achieved at 50% volume. Ensure the speaker is fully charged before use. If the issue persists after prolonged use, the battery may be degrading. |
| TWS pairing fails. | Speakers are too far apart; one speaker is already connected to a device. | Ensure speakers are within close proximity. Disconnect both speakers from any Bluetooth devices before initiating TWS pairing. |
10. Specifications
| Feature | Detail |
|---|---|
| Brand | Monster |
| Model Name | Monster Cubis |
| Speaker Maximum Output Power | 15 watts |
| Connectivity Technology | Auxiliary, Bluetooth |
| Bluetooth Version | 6.0 |
| Audio Output Mode | Stereo |
| Water Resistance Level | IPX7 (Waterproof) |
| Battery Average Life | 15 hours (at 50% volume) |
| Charging Port | USB-C |
| Item Dimensions (D x W x H) | 4D x 11W x 6H centimetres |
| Item Weight | 0.25 kg |
| Enclosure Material | Plastic |
| Control Method | Push Button |
| Additional Features | TWS Pairing, Built-in Mic, Hands-free Calling, Multi-Input Interfaces (AUX, TF Card) |
11. Warranty and Support
11.1. Warranty Information
The Monster Cubis Bluetooth Speaker comes with a 6 Months Limited Warranty from the date of purchase. This warranty covers manufacturing defects under normal use. It does not cover damage caused by misuse, accidents, unauthorized modifications, or normal wear and tear.
11.2. Customer Support
For technical assistance, warranty claims, or product inquiries, please contact Monster customer support. Manufacturer contact information is available through your point of purchase or on the official Monster website.