1. Nhanganyaya uye Pamusoroview
This manual provides detailed instructions for the installation, operation, and maintenance of your Gravity MGR-208BT Marine Stereo and Speaker System. Designed for marine environments, this system features a waterproof stereo receiver and 6.5-inch marine speakers with built-in LED lights, Bluetooth connectivity, and various audio playback options.

Image 1.1: The Gravity MGR-208BT Marine Stereo unit with two 6.5-inch marine speakers.
2. Safety Information
- Always disconnect the vehicle's battery before beginning any installation to prevent electrical shorts.
- Ensure all wiring connections are secure and properly insulated to prevent damage from moisture and vibration.
- Do not operate the stereo system at excessively high volumes for prolonged periods, as this may cause hearing damage.
- This product is designed for marine use with weather-resistant features. However, avoid direct high-pressure water jets on the unit.
- Bvunza nyanzvi yekuisa kana usina chokwadi nezve chero chikamu chekugadzirisa.
3. Package Zviri mukati
Ndokumbira utarise kuti zvinhu zvese zvakanyorwa pazasi zvinosanganisirwa mupakeji yako:
- 1 x Gravity MGR-208BT Bluetooth Marine Receiver
- 2 x Gravity 6.5-inch Marine Speakers with LED Lights
- 1 x Wire Harness
- 2 x Stereo Removal Keys
- 1 x Chinyorwa cheMushandisi (gwaro iri)
- 1 x Remote Control

Image 3.1: The Gravity MGR-208BT Marine Stereo Receiver unit.

Image 3.2: Two Gravity 6.5-inch Marine Speakers featuring built-in blue LED illumination.

Image 3.3: The remote control for the Gravity MGR-208BT Marine Stereo.
4. Setup uye Kuiswa
4.1 Stereo Receiver Installation
- Nzvimbo yekukwirisa: Choose a suitable location in your vessel that is protected from direct exposure to extreme weather conditions, although the unit is designed with a conformal-coated PCB for enhanced durability against moisture.
- Power Connection: Connect the yellow wire (constant 12V) to a constant 12V power source, the red wire (accessory 12V) to a switched 12V source, and the black wire (ground) to a reliable chassis ground.
- Kubatanidza Mutauri: Connect the speaker wires from the stereo's wire harness to your marine speakers. Ensure correct polarity (+/-) for optimal sound performance. The MGR-208BT supports a 4-channel output.
- Antenna: Connect your marine antenna to the designated input on the stereo.
- Secure Unit: Slide the stereo into the mounting sleeve until it clicks into place.
4.2 Kuiswa kweMutauri
The 6.5-inch marine speakers feature a low-profile design for easy integration into various marine watercrafts and off-road vehicles.
- Nzvimbo yekukwirisa: Select a flat surface for mounting. Ensure there is sufficient depth behind the mounting surface for the speaker magnet.
- Cheka-kunze: Use the provided template (if applicable, or refer to specifications for cut-out dimensions) to cut a circular opening for each speaker.
- Wiring: Connect the speaker wires from the stereo to the terminals on the back of each speaker. Observe correct polarity.
- MaSpika Akachengeteka: Mount the speakers using the supplied screws, ensuring a snug fit.

Mufananidzo 4.1: Kumashure view of a Gravity MG680-LW marine speaker, showing wiring terminals and specifications.
5. Operating Instructions
5.1 Basic Operation
- Batidza/Kudzima: Press the PWR bhatani rekubatidza kana kudzima unit.
- Kudzora inzwi: Rotate the central knob to adjust the volume level.
- Kwakabva Sarudzo Press the MODE button to cycle through available sources: Radio (AM/FM), CD, USB, AUX, and Bluetooth.
5.2 Kushanda kweBluetooth
- Kubatanidza: Select Bluetooth mode. On your mobile device, search for available Bluetooth devices and select "MGR-208BT". Enter "0000" if a passcode is required.
- Kutenderera Kwemumhanzi: Once paired, you can stream audio from your Bluetooth-enabled device to the stereo. Use your device or the stereo controls for playback (play/pause, skip track).
- Yakavakirwa-mukati Maikorofoni: The stereo includes a built-in Bluetooth microphone for hands-free calling.
5.3 USB and AUX Input
- USB Kutamba: Insert a USB drive into the front USB port. The unit will automatically switch to USB mode and begin playing compatible audio files (MP3, WMA, AAC, WAV, FLAC).
- AUX Input: Connect an external audio device (e.g., MP3 player) to the front AUX input using a 3.5mm audio cable. Select AUX mode to play audio from the connected device.
- iPod/iPhone Connection: Direct connection for iPod/iPhone is supported with an optional cable.
5.4 Kutamba kweCD
- Insert a CD into the disc slot. The unit will automatically switch to CD mode and begin playback.
- The unit plays CDs, CD-Rs, and CD-RW discs, including those loaded with MP3, WMA, AAC, and WAV music files.
5.5 Audio Settings
- Kudzora Manzwi: Press the SEL button repeatedly to access Bass and Treble adjustments. Use the volume knob to adjust values (Bass: +/-10dB, Treble: +/-10dB).
- Drive EQs: Improves sound quality to compensate for exterior noise.
- Sound Reconstruction: Restores fullness to compressed digital files.
- Low-Pass Filter & Sub Level Control: Adjust these settings for optimal subwoofer performance, if connected.
- Speaker Setting Function: Optimize audio output for different sizes and types of speakers.
5.6 Display and Faceplate
- The unit features a glare-resistant white display with variable-color illumination (up to 5 different tones).
- The faceplate is removable for theft deterrence. To remove, press the release button and gently pull the faceplate off. Store it in the provided case.

Image 5.1: The Gravity MGR-208BT Marine Stereo with its removable faceplate detached.

Image 5.2: The removable faceplate of the Gravity MGR-208BT stored in its protective case.
6. Kuchengeta
- Kuchenesa: Shandisa nyoro, damp cloth to clean the stereo unit and speakers. Avoid abrasive cleaners or solvents.
- Faceplate Care: When removed, store the faceplate in its protective case to prevent scratches and damage.
- Connections: Periodically check all wiring connections for corrosion or looseness, especially in marine environments.
- Kuramba Mvura: While the speakers are waterproof and the stereo has a conformal-coated PCB, ensure all covers (like USB/AUX input covers) are securely closed when not in use to maintain weather resistance.
7. Kugadzirisa matambudziko
| Dambudziko | Zvinogona Kukonzera | Solution |
|---|---|---|
| Hapana simba | Blown fuse; incorrect wiring; loose power connection. | Check and replace fuse; verify power and ground wiring; ensure connections are secure. |
| Hapana ruzha | Volume too low; incorrect source selected; speaker wires disconnected; amplifier protection mode. | Increase volume; select correct source; check speaker wiring; power cycle unit. |
| Bluetooth pairing yakundikana | Bluetooth not enabled on device; device too far; interference; incorrect pairing procedure. | Ensure Bluetooth is on and discoverable; move device closer; restart both devices; follow pairing steps in Section 5.2. |
| CD/USB playback error | Disc/USB damaged or incompatible format; dirty disc; incorrect file structure on USB. | Try a different disc/USB; clean disc; ensure files are compatible (MP3, WMA, AAC, WAV, FLAC). |
| Speakers not lighting up | LED power not connected or faulty. | Verify LED power connections (if separate); contact support if issue persists. |
8. Zvinotsanangurwa
- Muenzaniso: MGR-208BT
- Kubatana Technology: Bluetooth, USB
- Special Feature: Waterproof (speakers), Conformal-coated PCB (stereo)
- Zvishandiso Zvinoenderana: Smartphone, Mutauri
- Type yekubatanidza: USB
- Audio Output Mode: Stereo
- Yakapoteredza Sound Channel Configuration: 4 chiteshi
- Amplifier: Yakavakwa-mukati MOSFET amplifier (22 watts RMS/50 peak x 4 channels)
- Playback Formats: CDs, CD-Rs, CD-RWs, MP3, WMA, AAC, WAV (via CD/USB), FLAC (via USB)
- Ratidza: Glare-resistant white display, variable-color illumination (up to 5 tones)
- Kudzora Manzwi: Bass +/-10dB, Treble +/-10dB
- Additional Audio Features: Drive EQs, Sound Reconstruction, Low-pass filter, Sub level control, Speaker Setting function
- Faceplate: Removable theft-deterrent faceplate
- Chinhu Weight: Approximately 9.7 pounds (total package)
- Zviyero zvechigadzirwa: Approximately 9 x 12 x 8 inches (package)
9. Warranty uye Tsigiro
Your Gravity MGR-208BT Marine Stereo and Speaker System is covered by a manufacturer's warranty. Please refer to the warranty card included in your package for specific terms and conditions, including warranty duration and coverage details.
For technical support, troubleshooting assistance, or warranty claims, please contact your retailer or the manufacturer's customer service department. Contact information can typically be found on the product packaging or the manufacturer's official website.