JL Audio MediaMaster MM55 Marine 3-Zone Source Unit 010-03365-00 (99975)

JL Audio MediaMaster MM55 is a compact, weatherproof marine and powersports digital media receiver built for real open-air duty. A full-color 2.8" LCD, three audio zones, and intuitive rotary controls give you helm-friendly operation while the chassis, electronics, and user interface are engineered specifically for boats, UTVs, and other 12-volt platforms.

Behind the faceplate, the MM55 uses a Class-D 25W x 4 amplifier (2Ω-stable) to drive primary zones directly, plus nine 4V preamp outputs with selectable fixed/relative modes to feed JL amplifiers in larger systems. Integrated high-/low-pass crossovers, per-zone tone and volume limits, and IP67-rated construction, combined with AM/FM/DAB+, Bluetooth with aptX, USB audio, AUX, and NMEA 2000® connectivity, make it a true OEM-plus system controller rather than a generic head unit.

Key Features

• Weatherproof marine/powersports digital media receiver (no CD mechanism)
• Built-in Class-D amplifier: 25W RMS x 4 @ 4Ω (2Ω-stable)
• Three independent audio zones, each with its own subwoofer output and controls
• Nine channels of 4V preamp outputs (front/rear/sub per zone)
• 2.8" full-color TFT LCD with day/night brightness controls for screen and keys
• AM/FM/DAB+ tuner with RDS and up to 18 stored presets
• Bluetooth® audio streaming (A2DP/AVRCP) with SBC and aptX™ codec support
• Rear USB 2.0 input for thumb drives and digital audio (with 1A device charging)
• Rear stereo RCA AUX input with selectable input sensitivity
• NMEA 2000® network-ready for integration with compatible marine displays and JL remotes
• IP67-rated construction, designed for real-world marine and powersports environments

Technical Specifications

Ideal Applications

• Premium multi-zone marine audio on center consoles, pontoons, towboats, and cruisers
• Side-by-sides, UTVs, and other powersports builds needing robust weatherized controls
• Custom OEM-plus 12-volt systems where a compact, high-control source unit is required

Amplifier/Focus Matching

• Use the built-in 25W x 4 channels for primary cabin or cockpit speakers in smaller systems.
• Feed JL Audio marine amplifiers from the 4V preouts to power multiple zones, towers, and subwoofers.
• Pair with JL Audio M3/M6 speakers and JL marine subwoofers for consistent voicing across all zones.

What’s Included

• JL Audio MediaMaster MM55 marine source unit (010-03365-00, with 15A fuse)
• Trim ring (installed) and self-adhesive mounting gasket
• Power harness and speaker harness
• Mounting hardware and cutout template
• Owner’s manual and warranty information

Why Buy From MCOR Automotive

• Authorized JL Audio dealer with direct access to current spec and support information
• Real-world marine and powersports system design experience
• Application-focused guidance on zone layout, amplifier selection, and control strategy
• 20+ years in high-end 12-volt OEM-plus integration

JL Audio MM55 25Wx4 Marine Source Unit 010-03365-00

JL Audio MM55 marine digital media receiver with 25W x4 built-in amp, 3 audio zones, 4V preouts, Bluetooth, USB, IP67 design and NMEA 2000® integration for boats and powersports.

Fitment & Installation Help

Need help confirming fitment or installation parts? Use our Fit Guide or contact us through the chat button before ordering.

Authorized Retailer & Warranty

MCOR Automotive is an authorized JL Audio / Garmin retailer. Products purchased from MCOR include applicable manufacturer warranty coverage when installed and used according to manufacturer guidelines.