







Gravity MG660-LBK 6.5" 2-Way Marine Speakers
- Pair of 6.5-inch marine speakers
- Two-way full-range speaker design
- Built-in blue LED illumination
- Waterproof and weather-resistant listed
- Low-profile OEM-style replacement format
Product Info
| Brand | GRAVITY |
|---|---|
| Model / SKU | 787446976839 |
| UPC | 787446976839 |
| Availability | In stock and ready to quote |
The Gravity MG660-LBK is a pair of 6.5-inch two-way marine speakers designed for audio systems exposed to water, weather, and open-air use. It provides a practical replacement or upgrade option for boats, personal watercraft, and off-road vehicles that use a standard-size speaker location. The pair combines full-range speaker playback with integrated blue LED illumination.
These speakers are intended for listeners who want music in marine and outdoor vehicle applications without using conventional interior-only speakers. Their weather-resistant, waterproof-listed construction is made to handle heavy water splashes and outdoor conditions. The 6.5-inch format supports installation in many common OEM-style speaker positions, subject to verifying the actual opening and available mounting clearance.
The MG660-LBK uses a two-way speaker layout to cover both lower and higher portions of the audible range from each location. Gravity lists 350 watts of advertised power for the pair, though it does not publish an RMS rating or a power-rating test standard for this model. Match the speakers with a compatible marine or vehicle audio source and avoid relying on an unconfirmed continuous-power figure when selecting an amplifier.
Built-in blue LED lighting adds visual accent lighting around the speaker area for marine and outdoor installations. This makes the speakers suitable for systems where lighting is part of the overall vessel or powersports presentation. The lighting feature should be connected and protected according to the vehicle's electrical system requirements.
A low-profile design helps the MG660-LBK fit installations where rear-panel space is limited. It can be used as a direct replacement where fitment is confirmed, or as part of a larger system with a marine receiver, external amplifier, and additional speakers. Confirm mounting dimensions, wiring requirements, and speaker impedance before installation because detailed manufacturer installation specifications are not published for this SKU.
Key Features
- 6.5-Inch Size: Fits many standard marine and vehicle speaker locations.
- Two-Way Design: Combines full-range playback from each speaker location.
- Waterproof Listing: Intended for wet marine and outdoor environments.
- Weather Resistance: Built to handle water splashes and outdoor exposure.
- Blue LED Lighting: Adds illuminated styling to compatible installations.
- Low-Profile Form: Helps support installations with limited mounting space.
Design & Installation
The MG660-LBK is a white marine speaker pair with a slim, low-profile exterior intended for exposed recreational-vehicle environments. Its listed waterproof and weather-resistant characteristics are intended for marine, watercraft, and off-road applications. No IP rating, cone material, grille material, or basket material has been published for the exact UPC-listed product.
Before mounting, compare the existing opening, screw pattern, and rear clearance with the actual speakers, since detailed cutout and mounting-depth figures are not published. Connect each speaker with correct positive and negative polarity to a compatible audio system, and plan separate protected wiring as needed for the LED lighting. These speakers are best used in boats, marine watercraft, and off-road vehicles where a 6.5-inch OEM-style replacement size is appropriate.
| Brand | Gravity Professional |
|---|---|
| Model / SKU | MG660-LBK |
| Referenced Model Number | MG660 |
| UPC | 704129655775 |
| EAN | 0704129655775 |
| Product Type | Marine speakers |
| Speaker Configuration | 2-way |
| Speaker Size | 6.5 inches |
| Quantity | 1 pair (2 speakers) |
| Advertised Power | 350 watts |
| Power Rating Basis | Not published |
| RMS Power | Not published |
| Nominal Impedance | Not published |
| Frequency Response | Not published |
| Sensitivity | Not published |
| LED Lighting | Built-in blue LED lights |
| Water Resistance | Waterproof listed |
| Weather Resistance | Weather resistant |
| IP Rating | Not published |
| Design Profile | Low profile / slim style |
| Replacement Fitment | Universal standard OEM replacement size |
| Primary Applications | Boats and marine watercraft |
| Additional Applications | Off-road vehicles and outdoor use |
| Product Color | White |
| Package Dimensions | 15.0 x 7.9 x 3.9 inches |
| Mounting Depth | Not published |
| Mounting Cutout Diameter | Not published |
| Mounting Hardware | Not confirmed |
| LED Wiring Specifications | Not published |
| Warranty / Service Listing | 12-month return or exchange service |
| Release Date | August 30, 2018 |
Will these fit my boat's existing 6.5-inch speaker openings?
They are listed as 6.5-inch speakers with a universal standard OEM replacement size. Verify the cutout diameter, mounting-hole pattern, and rear clearance on your boat before purchase because exact mounting dimensions are not published.
Are these speakers suitable for marine use?
Yes. The product is listed as waterproof and weather resistant for boats, marine watercraft, and outdoor vehicle use. No IP rating or submersion-depth rating is published, so installation practices should still protect wiring and connections.
What is included in the package?
The listing confirms one pair of speakers, meaning two 6.5-inch marine speakers. It does not confirm mounting hardware, wiring, LED controllers, or other accessories.
How much power can the MG660-LBK handle?
The product listing advertises 350 watts of power for the pair. An RMS rating, per-speaker rating, and power-test standard are not published, so those values should not be assumed for amplifier matching.
Do the LED lights require separate wiring?
The speakers have built-in blue LED lights. The available product information does not document the LED voltage, current draw, connector type, or wiring method, so confirm those details from the product packaging before installation.
Is there a warranty or return policy?
The source listing states a 12-month return or exchange service. Coverage details, exclusions, and the responsible service provider are not otherwise published.




















